my s5 89 project. finally figured out the wiring n cant seem to get the lights to turn on. i got the front blinkers to turn on but they blink fast, cant get headlights or taillights to come on n also no running lights or brake lights either.

 

Check voltage?

 

havent yet where would i start checking it from? n what sould it be reading?

 

Headlight fuse is in the engine bay fuse box.

Headlights work like this..........turn the headlight switch to full ON. That sends a ground signal from the switch to the Headlight relay located in front and to the left of the radiator brace. The headlight relay has batt voltage on it 24/7 and all it needs is the ground signal from the headlight switch to pull in the relay and power up the headlights.

That's how things work on a series four and more than less on a series five.

Side lights get power from the Illumination fuse in the interior. How it gets thru the headlight switch to the tail/front side lights is a unknown to me when talking about series five. On a series four you'd just put the headlight switch to the first position and the power would pass thru the headlight switch to the front and side and tail lights.

Wiring manuals are online on this forum. On a series four car if you pull the headlight switches plug off, you'd see a white/green wire that has power 24/7 with or without the key in the ignition. That power passes thru the headlight switch and leaves the switch thru the Red/Black wire and goes to the lights on that wire.

Sooo, if you had the elect plug off the headlight switch and jumpered b/t the W/G wire in the plug to the R/B wire in that same plug.............walla........the side and tail lights will come on.

Diagram attached. Fuses have to be good.

One clue here is ...............if when you turn the headlight switch to ON, the headlights come up...............then it's a given the HEADLIGHT fuse in the engine bay is good and not the problem with the headlights. On a series five the headlights are perhaps also controlled by the CPU. I'm sure someone series five oriented will pipe in and clear that up.

That said..........I had my headlights fail at state inspection last yr. The wire at the bottom of the engine bay fuse box had come loose/off. thru my bad maint.

 

cool will try later 2day thx for great info. hopefully jus wat i needed