Technical No brake lights, indicators or windscreen wipers

[Bertybuoy]

Hi all - First time posting here so nice to meet you all!
My daughters Classic 500L has been working perfectly recently, but has suddenly it has developed an electrical fault that has stopped the brake lights working, the indicators and the windscreen wipers. Having checked the obvious fuses, I can see that the second fuse controls all three, so I thought it was going to be an easy fix! Unfortunately the fuses and contacts all test OK, so I'm now trying to trace a possible fault on the wiring diagram, but without any luck.
Could any of you kind people point me in the right direction please?

 

[smart51]

Do you have a multimeter? Check that there's 12V on either side of each fuse. Then check that 12V gets to one of the terminals on each switch. Then turn the switch on and check there's 12V to the other terminal. Finally check that the 12V gets to the bulb or motor. You can track down where the fault is easily enough.

 

[Bertybuoy]

Do you have a multimeter? Check that there's 12V on either side of each fuse. Then check that 12V gets to one of the terminals on each switch. Then turn the switch on and check there's 12V to the other terminal. Finally check that the 12V gets to the bulb or motor. You can track down where the fault is easily enough.

Thanks for your speedy response and sound advice. As I am remote from the car for another week, I am gathering thoughts and ideas in preparation. I haven't had the chance to use a multi-meter on it yet, but I was interested in what might be causing the fault 'upstream' of the individual faults that might be responsible for all three simultaneously happening. Any ideas on that?

 

[Bertybuoy]

I notice on the wiring diagram that there are a couple of connection blocks (I think numbered 17 on the diagram by memory) - could they possibly be a casue, and if so, do you know where they are located?

 

[smart51]

Fuse B (or 2) could be a common point. It is fed from the ignition switch. The feed also goes to the ignition coil. The other side of the fuse goes to the brake pedal switch and to the wiper motor. From there, it goes to Item 17, which is the plug that goes to the instrument cluster, and onwards to the indicator flasher relay.

I'd first start by checking if there is 12V on the red wire to the ignition switch. Be careful. It goes straight to the battery and there is no fuse. Then check that there is 12V on the blue/black wire from the switch when the switch is on. Then check 12V on both sides of the fuse.

 

[Bertybuoy]

Fuse B (or 2) could be a common point. It is fed from the ignition switch. The feed also goes to the ignition coil. The other side of the fuse goes to the brake pedal switch and to the wiper motor. From there, it goes to Item 17, which is the plug that goes to the instrument cluster, and onwards to the indicator flasher relay.

I'd first start by checking if there is 12V on the red wire to the ignition switch. Be careful. It goes straight to the battery and there is no fuse. Then check that there is 12V on the blue/black wire from the switch when the switch is on. Then check 12V on both sides of the fuse.

Many thanks… will do

 

[Bertybuoy]

Many thanks… will do

Thanks for the tips… I drive over to my daughter’s place and found a corroded contact on the fuse box… a good clean up and we’re back in business.
By the way, does anyone know the correct fuse ratings for all the fuses in the fuse box?
The ones that I have are all over the place!
Thanks again.

 

[Goldnrust]

Glad to hear you got it fixed.

All fuses should be 8 amp.

 

[Bertybuoy]

Glad to hear you got it fixed.

All fuses should be 8 amp.

Many thanks