HELP! : Wiring conundrum - Voltage drop when circuit created
Posted: Tue Nov 21, 2023 9:41 am
Hi All,
I am in the final days of my GTV6 restoration, before taking the car back to Oom Dawie to get driveshaft properly fitted and new exhaust made up.
Have connected a battery up to the car for the 1st time in 4 years and busy testing ALL circuits. I re-crimped many terminals on the wiring harnesses due to poor connections and new harness tape. I also have tons of video I made when removing all components.
So far circuits working are front lights, power windows, inside lights, rear demister, hooter, radiator fans etc
My conundrum starts with the rear harness and the front indicator lights as well as windscreen wipers.
These circuits are not working. I will disconnect all components and the trace power through.
So for example, brake pedal switch is sending 12v to rear. Bridged reverse light switch send 12v to rear.
The moment I try to form a circuit through the lights by earthing, Relay 4 and the relay in engine where bosch harness joins into main harness Click, and the Voltage drops away to nothing with lights not working...
The moment I remove the earth side, the relays "reset" 12v comes back to the +ve side of these lights.
And so I repeat.
What was also quite strange is that on the weekend, the coil with the 3 wires to it, basically ruptured (even though engine has not even started yet, so no sparks being generated).
So there is clearly a circuit problem somewhere, but I am at a loss. I have the wiring diagrams and have tested what I can.....
Any ideas on what I should check would be much appreciated.
Thanks Mike
I am in the final days of my GTV6 restoration, before taking the car back to Oom Dawie to get driveshaft properly fitted and new exhaust made up.
Have connected a battery up to the car for the 1st time in 4 years and busy testing ALL circuits. I re-crimped many terminals on the wiring harnesses due to poor connections and new harness tape. I also have tons of video I made when removing all components.
So far circuits working are front lights, power windows, inside lights, rear demister, hooter, radiator fans etc
My conundrum starts with the rear harness and the front indicator lights as well as windscreen wipers.
These circuits are not working. I will disconnect all components and the trace power through.
So for example, brake pedal switch is sending 12v to rear. Bridged reverse light switch send 12v to rear.
The moment I try to form a circuit through the lights by earthing, Relay 4 and the relay in engine where bosch harness joins into main harness Click, and the Voltage drops away to nothing with lights not working...
The moment I remove the earth side, the relays "reset" 12v comes back to the +ve side of these lights.
And so I repeat.
What was also quite strange is that on the weekend, the coil with the 3 wires to it, basically ruptured (even though engine has not even started yet, so no sparks being generated).
So there is clearly a circuit problem somewhere, but I am at a loss. I have the wiring diagrams and have tested what I can.....
Any ideas on what I should check would be much appreciated.
Thanks Mike