Electrical Nightmare... Help!!!

[Guest Andy H]

Hi all

please, please, please can anyone shed a little light on why my heater, indicators and wipers have packed up its all went at the same time yet my rear windows, dash lights and interior lights are still working i hope to god its not the fuse box

[Guest Paul Grainger]

I am afraid it could be the fuse box. There is however an ign feed relay that feeds these items on top of the fuse box, so it is worth checking this first. Get a manual to show which ones are which, as there are different fuse box configuratons.

Good luck

[Guest Andy H]

hi paul

and thanks only checked the fuses so far how can you tell if the relay has gone??

[Guest Paul Grainger]

If you pull them out one by one, you can check them with a multimeter and a 9v battery like a pp3.

 

Pins 30 ans 87 is the load circuit, test the resistance across these teminals, (should be open circuit)

Then put the teminals of your battery across the other two pins (85 and 86), (you should hear a click as the contacts close). Check the resistace again whilst holding the battery on. the resistance should read below 5 ohms.

 

If you think one is a bit dodgey then you could always try swapping it temporarily with another to see if it makes a difference.

 

One thing to watch is that some relays have diodes fitted, and will only operate if the battery is the right way round, so try it both ways. Also some relays have five pins, the extra is 87a which should be open circuit when 87 is closed, and is closed when 87 is open.

 

Good luck