H4 bulb question
02-07-2006 | 01:53 PM
#1
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Posts: 5,631
From: Montreal
H4 bulb question
I was looking through a parts catalogue looking for a Xenon H4 bulb to add some much needed candlepower to my VTR (same 60/55 rating). I was unsure which type to order as they have two H4 sub-types listed: P45T and P43T. Does anyone know which is the one in the VTR? Can anyone "shed light" on the topic? 
cheers
Mikstr
cheers
Mikstr
02-07-2006 | 03:38 PM
#2
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Posts: 147
From: Los Angeles, California, Canyons = SMM's, ACH,
Re: H4 bulb question
The shawks voltage drop (with both stock wiring and headlight bulb) is 1
volt measured from the positive battery terminal to the headlight socket.
It's almost 2 volt drop with both beams on, (dimmer switch in mid-position
for canyons at night).
And this is with the stock 60/55 watt bulb.
Furthermore the OEM fuse box (that the headlight circuit is wired though)
is where a large part of the voltage drop occurs, so the headlight circuit
drops voltage to every other circuit fed though the box as well. By
eliminating the high current headlight circuit the rest of the circuits
have more than enough current carrying capability.
Here's a dedicated circuit I just installed on the SV1000S
Since I needed a relayed circuit for my monitor anyway and measured a 1.9 high and 1.6 low beam voltage drop at the headlight sockets.
So it seemed logical to install a dedicated headlight harness at the same time.
I used 12 AWG wire and afterward measured only .16 voltage drop at both lamps.
Took some pictures during the project.
One of the tricks of the trade is building most of the harness outside of the bike and then routing it in just before crimping the last key connectors.
http://tinyurl.com/8a957
"Normal engine-running voltage in a "12-volt" automotive electrical system
is around 13.5 volts. At this voltage, halogen headlamp bulbs achieve 100
percent of their design luminous output. When operating voltage drops to 95
percent (12.825v), headlamp bulbs produce only 83 percent of their rated
light output. When voltage drops to 90 percent (12.15v), bulb output is only
67 percent of what it should be. And when voltage drops to 85 percent
(11.475v), bulb output is a paltry 53 percent of normal!" [Source: Hella KG
Hueck AG, Germany]
Heavy Duty H4 headlight socket $7
30 amp relays $6 x 2
male spade terminals x 2 (for relay signal from OEM H4 socket)
female spade connectors x 8 (for relay connections)
1 butt connector (for fuse holder connection)
battery terminal connectors x 2
30 amp waterproof inline fuse holder $2
12/14 gauge wire $3
volt measured from the positive battery terminal to the headlight socket.
It's almost 2 volt drop with both beams on, (dimmer switch in mid-position
for canyons at night).
And this is with the stock 60/55 watt bulb.
Furthermore the OEM fuse box (that the headlight circuit is wired though)
is where a large part of the voltage drop occurs, so the headlight circuit
drops voltage to every other circuit fed though the box as well. By
eliminating the high current headlight circuit the rest of the circuits
have more than enough current carrying capability.
Here's a dedicated circuit I just installed on the SV1000S
Since I needed a relayed circuit for my monitor anyway and measured a 1.9 high and 1.6 low beam voltage drop at the headlight sockets.
So it seemed logical to install a dedicated headlight harness at the same time.
I used 12 AWG wire and afterward measured only .16 voltage drop at both lamps.
Took some pictures during the project.
One of the tricks of the trade is building most of the harness outside of the bike and then routing it in just before crimping the last key connectors.
http://tinyurl.com/8a957
"Normal engine-running voltage in a "12-volt" automotive electrical system
is around 13.5 volts. At this voltage, halogen headlamp bulbs achieve 100
percent of their design luminous output. When operating voltage drops to 95
percent (12.825v), headlamp bulbs produce only 83 percent of their rated
light output. When voltage drops to 90 percent (12.15v), bulb output is only
67 percent of what it should be. And when voltage drops to 85 percent
(11.475v), bulb output is a paltry 53 percent of normal!" [Source: Hella KG
Hueck AG, Germany]
Heavy Duty H4 headlight socket $7
30 amp relays $6 x 2
male spade terminals x 2 (for relay signal from OEM H4 socket)
female spade connectors x 8 (for relay connections)
1 butt connector (for fuse holder connection)
battery terminal connectors x 2
30 amp waterproof inline fuse holder $2
12/14 gauge wire $3
02-07-2006 | 04:24 PM
#3
Senior Member
Superstock
Joined: Jan 2006
Posts: 402
From: Florida
Re: H4 bulb question
H4 P45T has a 45mm fitting
and
H4 P43T has a 43mm fitting and has two tabs you line up in the mounting.
You need the P43T I believe since the 45T does not appear to have the two tabs.
I will double check mine when I get home later. I took the bulbs out of a crashed R6.
and
H4 P43T has a 43mm fitting and has two tabs you line up in the mounting.
You need the P43T I believe since the 45T does not appear to have the two tabs.
I will double check mine when I get home later. I took the bulbs out of a crashed R6.
02-07-2006 | 06:09 PM
#5
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Posts: 147
From: Los Angeles, California, Canyons = SMM's, ACH,
Re: H4 bulb question
It's a seperate relay for each beam, Hi/Lo.
So that's the same with shawk and SV (single and dual headlights)
I done the same mod on both bikes including the LED charging system monitors.
Makes a noticeable differance in light output. Also on the shawk I have it wired so that low beam is always on, then when you select Hi beam you get both on. This gives you a better spread of beam at night and helps get you noticed for lane splitting here in California where it's legal to do.
If you ran both beams without relays there's a 2 volt voltage drop, and the headlight's more yellow than white.
~Jeffers
So that's the same with shawk and SV (single and dual headlights)
I done the same mod on both bikes including the LED charging system monitors.
Makes a noticeable differance in light output. Also on the shawk I have it wired so that low beam is always on, then when you select Hi beam you get both on. This gives you a better spread of beam at night and helps get you noticed for lane splitting here in California where it's legal to do.
If you ran both beams without relays there's a 2 volt voltage drop, and the headlight's more yellow than white.
~Jeffers
02-07-2006 | 06:35 PM
#6
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Superstock
Joined: Jan 2006
Posts: 402
From: Florida
Re: H4 bulb question
mikstr,
I pulled the bulb and it is a P43T 12v H4 Blue tint.
(three tabs not two)
I did notice an improvement with the H4 bulb; however, Caffineracer may be on to something with the voltage drop. Most motorcycle electrical systems do seem operate close to the designed limits. The bulb won't fry your system, but I can believe it could draw down the voltage enough to not give the full brightness the bulb should.
I pulled the bulb and it is a P43T 12v H4 Blue tint.
(three tabs not two)
I did notice an improvement with the H4 bulb; however, Caffineracer may be on to something with the voltage drop. Most motorcycle electrical systems do seem operate close to the designed limits. The bulb won't fry your system, but I can believe it could draw down the voltage enough to not give the full brightness the bulb should.
02-07-2006 | 07:07 PM
#7
Senior Member
SuperSport
Joined: Sep 2005
Posts: 882
From: Dallas, TX
Re: H4 bulb question
It's a seperate relay for each beam, Hi/Lo.
So that's the same with shawk and SV (single and dual headlights)
I done the same mod on both bikes including the LED charging system monitors.
Makes a noticeable differance in light output. Also on the shawk I have it wired so that low beam is always on, then when you select Hi beam you get both on. This gives you a better spread of beam at night and helps get you noticed for lane splitting here in California where it's legal to do.
If you ran both beams without relays there's a 2 volt voltage drop, and the headlight's more yellow than white.
~Jeffers
So that's the same with shawk and SV (single and dual headlights)
I done the same mod on both bikes including the LED charging system monitors.
Makes a noticeable differance in light output. Also on the shawk I have it wired so that low beam is always on, then when you select Hi beam you get both on. This gives you a better spread of beam at night and helps get you noticed for lane splitting here in California where it's legal to do.
If you ran both beams without relays there's a 2 volt voltage drop, and the headlight's more yellow than white.
~Jeffers
I thought the VTR's light was pretty good untill I rode with a '04 R1 last weekend.
Dang his lights were bright!
Do you have a sketch of the wiring diagram for the VTR?
How did you wire it so both Hi & Lo are both on when the Hi beam switch is on?
Thanks, BIll
02-07-2006 | 08:00 PM
#8
Thread Starter
Senior Member
MotoGP
Joined: Apr 2005
Posts: 5,631
From: Montreal
Re: H4 bulb question
Thanks Bird
I must confess that I am a bit "electrically challenged" should we say. If I am following what you are saying then Jeff, the stock fuse box and wires are the source of a significant drop in voltage between the battery and the bulb? If, so, what do you think is the main cause? The wire diameter too small causing too much resistance?
Forgive my ignorance but what exactly is a relay? a switch?
Could I simply run a separate circuit from the battery to the hi-low beam switch (with an in-line fuse in between), then go to the bulb?
Sorry for being slow but mechanical stuff= no problems, electrical stuff=problems.
One last thing, I was thinking of disconnecting the small "driving light" at the front as it serves no real purpose (just wasting power that could otherwise go to the headlight)
cheers (hopefully no jeers!)
Mikstr
I must confess that I am a bit "electrically challenged" should we say. If I am following what you are saying then Jeff, the stock fuse box and wires are the source of a significant drop in voltage between the battery and the bulb? If, so, what do you think is the main cause? The wire diameter too small causing too much resistance?
Forgive my ignorance but what exactly is a relay? a switch?
Could I simply run a separate circuit from the battery to the hi-low beam switch (with an in-line fuse in between), then go to the bulb?
Sorry for being slow but mechanical stuff= no problems, electrical stuff=problems.
One last thing, I was thinking of disconnecting the small "driving light" at the front as it serves no real purpose (just wasting power that could otherwise go to the headlight)
cheers (hopefully no jeers!)
Mikstr
02-07-2006 | 09:42 PM
#9
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Back Marker
Joined: Dec 2004
Posts: 147
From: Los Angeles, California, Canyons = SMM's, ACH,
Re: H4 bulb question
Here's a diagram of the circuit.
http://www.humanspeakers.com/audi/headlight-simple.htm
For both beams to be on when you select hi beam?
Find the three wires going to your hi/lo handlebar switch.
one is hot (with key on)
one is hi beam
one is lo beam
Place a jumper between hot and lo beam.
(you can do it with one of those 'tap' connectors)
Now lo beam is always on, and hi beam is added to lo when you select hi beam.
This only works after you've installed a dedicated headlight circuit with relays. Otherwise the voltage drop is so great the beams are yellow instead of white.
~Jeffers
http://www.humanspeakers.com/audi/headlight-simple.htm
For both beams to be on when you select hi beam?
Find the three wires going to your hi/lo handlebar switch.
one is hot (with key on)
one is hi beam
one is lo beam
Place a jumper between hot and lo beam.
(you can do it with one of those 'tap' connectors)
Now lo beam is always on, and hi beam is added to lo when you select hi beam.
This only works after you've installed a dedicated headlight circuit with relays. Otherwise the voltage drop is so great the beams are yellow instead of white.
~Jeffers
02-07-2006 | 09:54 PM
#10
Senior Member
SuperSport
Joined: Sep 2005
Posts: 882
From: Dallas, TX
Re: H4 bulb question
Here's a diagram of the circuit.
http://www.humanspeakers.com/audi/headlight-simple.htm
For both beams to be on when you select hi beam?
Find the three wires going to your hi/lo handlebar switch.
one is hot (with key on)
one is hi beam
one is lo beam
Place a jumper between hot and lo beam.
(you can do it with one of those 'tap' connectors)
Now lo beam is always on, and hi beam is added to lo when you select hi beam.
This only works after you've installed a dedicated headlight circuit with relays. Otherwise the voltage drop is so great the beams are yellow instead of white.
~Jeffers
http://www.humanspeakers.com/audi/headlight-simple.htm
For both beams to be on when you select hi beam?
Find the three wires going to your hi/lo handlebar switch.
one is hot (with key on)
one is hi beam
one is lo beam
Place a jumper between hot and lo beam.
(you can do it with one of those 'tap' connectors)
Now lo beam is always on, and hi beam is added to lo when you select hi beam.
This only works after you've installed a dedicated headlight circuit with relays. Otherwise the voltage drop is so great the beams are yellow instead of white.
~Jeffers
02-08-2006 | 07:29 AM
#11
Thread Starter
Senior Member
MotoGP
Joined: Apr 2005
Posts: 5,631
From: Montreal
Re: H4 bulb question
Hello again,
thanks for all the info. Just a few more questions (trying to understand all of this and learn from it):
1) is a relay just a switch or does it serve some other function?
2) what do you think is causing the significant current loss between the power source and headlight? The reason I ask this is I am having a difficult time understanding how simply re-routing the circuit will seemingly unlock hidden voltage. At the end of the day, the magneto (or alternator or whatever is generating teh power) produces only so much output so whether you route it through circuit A (OEM) or B should not really matter unless somehow there is power loss by routing it through A (which is not present in B). If this is not the case, what you are doing, in effect, is draining the battery over time are you not?
I realize these questions may sound silly but I really want to grasp what is happening here.
thanks in advance
Mikstr
thanks for all the info. Just a few more questions (trying to understand all of this and learn from it):
1) is a relay just a switch or does it serve some other function?
2) what do you think is causing the significant current loss between the power source and headlight? The reason I ask this is I am having a difficult time understanding how simply re-routing the circuit will seemingly unlock hidden voltage. At the end of the day, the magneto (or alternator or whatever is generating teh power) produces only so much output so whether you route it through circuit A (OEM) or B should not really matter unless somehow there is power loss by routing it through A (which is not present in B). If this is not the case, what you are doing, in effect, is draining the battery over time are you not?
I realize these questions may sound silly but I really want to grasp what is happening here.
thanks in advance
Mikstr
02-08-2006 | 07:34 AM
#12
Thread Starter
Senior Member
MotoGP
Joined: Apr 2005
Posts: 5,631
From: Montreal
Re: H4 bulb question
Just thought of two more:
1) why replace the stock bulb socket? Why not just hook up the wiring to the stock one?
2) does running both beams at once increase the chance of failure, or decrease the life of the bulb (excessive heat?)? I would think that this is especially critical given taht the VTR only has one bulb (would leave you in a real pickle if both beams burned out at once while riding at night)
thanks again
Mikstr
1) why replace the stock bulb socket? Why not just hook up the wiring to the stock one?
2) does running both beams at once increase the chance of failure, or decrease the life of the bulb (excessive heat?)? I would think that this is especially critical given taht the VTR only has one bulb (would leave you in a real pickle if both beams burned out at once while riding at night)
thanks again
Mikstr
02-08-2006 | 08:18 AM
#13
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Joined: Dec 2004
Posts: 147
From: Los Angeles, California, Canyons = SMM's, ACH,
Re: H4 bulb question
You need the heavier gauge wire that the aftermarket socket has 12/14 gauge.
Or you can build you own socket with 3/8" spade connectors, like I did on the SV.
With a stock bulb I haven't had any problem running both beams at once.
Even lane splitting in the summer months nothing has melted and filments haven't burnt out both at once.
Also a picture of a socket I made for thr KLR in my Yahoo picture album.
~Jeffers
Or you can build you own socket with 3/8" spade connectors, like I did on the SV.
With a stock bulb I haven't had any problem running both beams at once.
Even lane splitting in the summer months nothing has melted and filments haven't burnt out both at once.
Also a picture of a socket I made for thr KLR in my Yahoo picture album.
~Jeffers
02-08-2006 | 01:54 PM
#14
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Back Marker
Joined: Dec 2004
Posts: 147
From: Los Angeles, California, Canyons = SMM's, ACH,
Re: H4 bulb question
Hello again,
thanks for all the info. Just a few more questions (trying to understand all of this and learn from it):
1) is a relay just a switch or does it serve some other function?
=====
The relay is just a switch, but it's able to carry 30amps (plenty of current for your headlight)
And it can be controlled by a much lower rated switch ( the hi/lo beam switch on the left handlebar)
=====
2) what do you think is causing the significant current loss between the power source and headlight?
=====
The stock 18/16 awg wires themselves don't carry enough current,
the hi/lo beam switch on the left handlebar,
the ignition switch, and terminal block all add to the total resistance of the circuit.
If you put a high enough wattage head lamp in with stock wiring it could drop enough voltage that it would actually be dimmer than the stock light.
=====
The reason I ask this is I am having a difficult time understanding how simply re-routing the circuit will seemingly unlock hidden voltage.
=====
We're re-routing thru a circuit that has less resistance to current flow, so it carrys more current to the headlights.
=====
At the end of the day, the magneto (or alternator or whatever is generating teh power) produces only so much output so whether you route it through circuit A (OEM) or B should not really matter unless somehow there is power loss by routing it through A (which is not present in B). If this is not the case, what you are doing, in effect, is draining the battery over time are you not?
I realize these questions may sound silly but I really want to grasp what is happening here.
thanks in advance
Mikstr
thanks for all the info. Just a few more questions (trying to understand all of this and learn from it):
1) is a relay just a switch or does it serve some other function?
=====
The relay is just a switch, but it's able to carry 30amps (plenty of current for your headlight)
And it can be controlled by a much lower rated switch ( the hi/lo beam switch on the left handlebar)
=====
2) what do you think is causing the significant current loss between the power source and headlight?
=====
The stock 18/16 awg wires themselves don't carry enough current,
the hi/lo beam switch on the left handlebar,
the ignition switch, and terminal block all add to the total resistance of the circuit.
If you put a high enough wattage head lamp in with stock wiring it could drop enough voltage that it would actually be dimmer than the stock light.
=====
The reason I ask this is I am having a difficult time understanding how simply re-routing the circuit will seemingly unlock hidden voltage.
=====
We're re-routing thru a circuit that has less resistance to current flow, so it carrys more current to the headlights.
=====
At the end of the day, the magneto (or alternator or whatever is generating teh power) produces only so much output so whether you route it through circuit A (OEM) or B should not really matter unless somehow there is power loss by routing it through A (which is not present in B). If this is not the case, what you are doing, in effect, is draining the battery over time are you not?
I realize these questions may sound silly but I really want to grasp what is happening here.
thanks in advance
Mikstr
02-08-2006 | 01:57 PM
#15
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Back Marker
Joined: Dec 2004
Posts: 147
From: Los Angeles, California, Canyons = SMM's, ACH,
Opps, you have to read my post though mikstr's quote.
Hello again,
thanks for all the info. Just a few more questions (trying to understand all of this and learn from it):
1) is a relay just a switch or does it serve some other function?
=====
The relay is just a switch, but it's able to carry 30amps (plenty of current for your headlight)
And it can be controlled by a much lower rated switch ( the hi/lo beam switch on the left handlebar)
=====
2) what do you think is causing the significant current loss between the power source and headlight?
=====
The stock 18/16 awg wires themselves don't carry enough current,
the hi/lo beam switch on the left handlebar,
the ignition switch, and terminal block all add to the total resistance of the circuit.
If you put a high enough wattage head lamp in with stock wiring it could drop enough voltage that it would actually be dimmer than the stock light.
=====
The reason I ask this is I am having a difficult time understanding how simply re-routing the circuit will seemingly unlock hidden voltage.
=====
We're re-routing thru a circuit that has less resistance to current flow, so it carrys more current to the headlights.
=====
At the end of the day, the magneto (or alternator or whatever is generating teh power) produces only so much output so whether you route it through circuit A (OEM) or B should not really matter unless somehow there is power loss by routing it through A (which is not present in B). If this is not the case, what you are doing, in effect, is draining the battery over time are you not?
I realize these questions may sound silly but I really want to grasp what is happening here.
thanks in advance
Mikstr
Hello again,
thanks for all the info. Just a few more questions (trying to understand all of this and learn from it):
1) is a relay just a switch or does it serve some other function?
=====
The relay is just a switch, but it's able to carry 30amps (plenty of current for your headlight)
And it can be controlled by a much lower rated switch ( the hi/lo beam switch on the left handlebar)
=====
2) what do you think is causing the significant current loss between the power source and headlight?
=====
The stock 18/16 awg wires themselves don't carry enough current,
the hi/lo beam switch on the left handlebar,
the ignition switch, and terminal block all add to the total resistance of the circuit.
If you put a high enough wattage head lamp in with stock wiring it could drop enough voltage that it would actually be dimmer than the stock light.
=====
The reason I ask this is I am having a difficult time understanding how simply re-routing the circuit will seemingly unlock hidden voltage.
=====
We're re-routing thru a circuit that has less resistance to current flow, so it carrys more current to the headlights.
=====
At the end of the day, the magneto (or alternator or whatever is generating teh power) produces only so much output so whether you route it through circuit A (OEM) or B should not really matter unless somehow there is power loss by routing it through A (which is not present in B). If this is not the case, what you are doing, in effect, is draining the battery over time are you not?
I realize these questions may sound silly but I really want to grasp what is happening here.
thanks in advance
Mikstr
02-09-2006 | 08:12 AM
#18
Senior Member
Back Marker
Joined: Dec 2004
Posts: 147
From: Los Angeles, California, Canyons = SMM's, ACH,
02-09-2006 | 09:28 AM
#19
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SuperSport
Joined: Sep 2005
Posts: 882
From: Dallas, TX
02-09-2006 | 09:31 AM
#20
Moderate-whore
MotoGP
Joined: Nov 2005
Posts: 9,049
From: Leander TX!!
Re: H4 bulb question
I think Ohmslaw has less Mayonaise in it....thus producing less gas/indigestion.....
02-13-2006 | 06:11 PM
#21
Senior Member
Superstock
Joined: Jan 2006
Posts: 402
From: Florida
Re: H4 bulb question
Watt?
I find the hole theory quite stimulating.
Once you have the basics of Ohm's law in hand you will be shocked at how en-lightened you feel
Currently you can ask ELI the ICE man, about the left hand rule.
It is attractive and can give you some direction.
I don't want to load you down, with any negative thoughts.
Just remember to be positive and go with the flow.
:wink:
I find the hole theory quite stimulating.
Once you have the basics of Ohm's law in hand you will be shocked at how en-lightened you feel
Currently you can ask ELI the ICE man, about the left hand rule.
It is attractive and can give you some direction.
I don't want to load you down, with any negative thoughts.
Just remember to be positive and go with the flow.
:wink:
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