Topic: Anyone out there using Bosh Headlight System on C3
in Forum: C3 Electrical
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Mine were installed by previous owner, Don't know why But they are not working properly. Shut down when at engine idle and come on again at RPM increase . Alternator seams to be OK output is fine,
My Two Babies!!!!
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Sounds like a regulator problem. Does all the other electrics still work at idle, like dash lights and stereo etc? Maybe try putting a smaller pulley on the alternator (to make it spin faster at idle)



They may be drawing too much power for the system. The headlight switch has a circuit breaker built in to prevent overload. The wires will handle it, but if the breaker is overloaded the lights will come on for a while, the go out. After some time they will come back on and then go out again.
The time they are on depends on the current draw through the breaker.
The H3 light do draw more power. If you find this is the problem, you can connect the headlight feeds to operate a relay instead of the lights directly, the circuit breaker won't overload. Then you can fuse the power supply to the relay and supply the lights with all the necessary power.
If you need it, I will draw up a diagram how to do this and post it.
The time they are on depends on the current draw through the breaker.
The H3 light do draw more power. If you find this is the problem, you can connect the headlight feeds to operate a relay instead of the lights directly, the circuit breaker won't overload. Then you can fuse the power supply to the relay and supply the lights with all the necessary power.
If you need it, I will draw up a diagram how to do this and post it.
I spent a bit of time with my Corel Draw tonight.
Here is the mod diagram. You can use the battery lead on the back of the alternator for a great power supply. Be sure to use fuses

This can also work if your headlights seem a bit dim. The more direct current path prevents a voltage drop through old wireing resulting in dim lights.
If you turn on your lights and have less than 1/2 volt drop from battery voltage, the lights will start to dim a bit. If they are a couple of volts down, they will be quite dim.
But it will also solve the over current problem the brighter lights will cause with the headlight circuit breaker.
|UPDATED|1/9/2005 9:24:12 PM (AZT)|/UPDATED|
Here is the mod diagram. You can use the battery lead on the back of the alternator for a great power supply. Be sure to use fuses

This can also work if your headlights seem a bit dim. The more direct current path prevents a voltage drop through old wireing resulting in dim lights.
If you turn on your lights and have less than 1/2 volt drop from battery voltage, the lights will start to dim a bit. If they are a couple of volts down, they will be quite dim.
But it will also solve the over current problem the brighter lights will cause with the headlight circuit breaker.
|UPDATED|1/9/2005 9:24:12 PM (AZT)|/UPDATED|
Ken, that seems very easy to do. I wonder why they just didn't do this to begin with. This will also save the headlight switch a lot of greif also. Very nice diagram. Do you have any idea how big of a relay is needed?
A standard bosch relay is fine. Most of them will handle 30 amps with no problem. Over that is a bit much, but the lights will pull less than that.
You can get them at some parts houses for 20 bucks, or I could give you an Autozone part number for 12 bucks, or just go to the fog/driving lights at Autozone and you will see a relay for 4 or 5 bucks. It's labeled as a light relay.
Just a square box with a mounting tab on the edge. It has 5 terminals, you only need four.
Looking on the relay and you can see the wiring diagram. Two terminals are the control circut show in my diagram with the jagged line in the relays. Then there is one that will contact either one of the remaining two, depending if it's on or off. Just don't use the one contacted in the off position.
When you look at the diagram, it's easy.
|UPDATED|1/11/2005 7:11:49 PM (AZT)|/UPDATED|
You can get them at some parts houses for 20 bucks, or I could give you an Autozone part number for 12 bucks, or just go to the fog/driving lights at Autozone and you will see a relay for 4 or 5 bucks. It's labeled as a light relay.
Just a square box with a mounting tab on the edge. It has 5 terminals, you only need four.
Looking on the relay and you can see the wiring diagram. Two terminals are the control circut show in my diagram with the jagged line in the relays. Then there is one that will contact either one of the remaining two, depending if it's on or off. Just don't use the one contacted in the off position.
When you look at the diagram, it's easy.
|UPDATED|1/11/2005 7:11:49 PM (AZT)|/UPDATED|
in Forum: C3 Electrical
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