sidelights / tailights / licence plate lights / instrument panel lights / aircon panel lights

[nanardos]

Hi All,

The sidelights / tail lights / licence plate lights / instrument panel lights / aircon panel lights have suddenly stopped working on my 1987 S3 Turbo HCI (US car)

I have checked/ replaced all the related fuses but got no improvement.

The headlight (low and high beam work fine

Any ideas ?

Bernard

[Sparky]

As all of those are governed by a single switch, that's where I'd start.

[Escape]

Indeed, the light switch is the same as in my Excel. Those can fail in just one position. Take it out to get access to the wiring and check if you have 12V on the red/green wire. If not, chances are it's the internal contact that has worn. Sometimes cleaning is enough to get it working again, if not you'll need to replace the switch.

[nanardos]

I just ordered a new switch 

[nanardos]

I just replaced the light switch (a nightmare...)  , everything is working again.

[nanardos]

Oops , the lights work fine but the car won't start...

I don't quite understand why there would be a relation ship with the replacement of the light switch but it seems that the fuel pumps are not working.

I have checked all the related fuses and relays but did not find anything wrong.

Any idea ?

[snowrx]

Have you checked for a inertia/rollover fuel pump safety switch? My '85 has one in the wall between engine and trunk. if it's popped it interrupts the fuel pump power. 

 

[Escape]

Go over things step by step:

- the engine is turning over but not firing? -> either fuel or spark is missing
- does the fuel pump come on? If not, try jumping the relay.
- there is an inertia switch in the circuit (as mentioned) as well as an overboost switch, both can prevent the fuel pumps from coming on.

Do you have the diagram for the fuel pump circuit?

[nanardos]

Hi,

I have checked all that.

The problem seems to come from a faulty primary pump.

I will keep you informed.

Thanks

 

Bernard

[Escape]

If you swap the electrical connections to the primary and secondary pumps, you can prove that theory.

[nanardos]

Faulty primary pump confirmed