Electrical wiring Guru please help

[Adey]

Hi all, I have a funny electrical fault with my Twingo and could do with a wizard to direct me where to look for the issue. With diagnostic equipment if I activate the low speed rad fan it will run fine, if I request the high speed fan the fuse will pop (share the fuse by the looks of it?), the stop light will illuminate on the dash and I will get a warning beep. I also have the warning beep and light illuminate briefly when starting the car. And it will also intermittently do the same when powering my boost bypass solenoid (totally independent system, simple switched relay control) So I'm pretty sure I have an earth fault that is isolated to the high speed fan side of the circuit, though I could be wrong. Where do I test between to find it..... this is where I need your help.

Attached is a wiring diagram and codes for items. I've checked the diodes are in the correct direction as per their markings.

234 fan relay
597 fusebox
120 ecu
700 perc fan low speed
238 injection lock
321 resistor
965 low speed anti return diode, 1st threshold temp switch
262 fan

 

[Red21]

With out being there and prodding things, my first guess would be 965 diode or one of the diodes in the relays.
Try disconnecting the resistor on the rad fan cowl & the diode in the engine bay fuse box and see what happens.

 

[Adey]

make sure you have everything plugged in the correct place would stop this happening. The resistor pack and fan use the same plug and are next to each other

 

[Red21]

Sorted then,

 

[Adey]

Sorted then,

Yeah, just needed some down time to stop over thinking it. Sat and drew the wiring out myself this morning so I could follow it and then had the thought..

What a twat lol