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Couple of electrical problems
Posted: Tue May 19, 2020 6:15 pm
by Fox
When I got my car out of the workshop i noticed my speedometer, odometer, info center and the side indicators were dead. After I took out the CEM and back in, the pop up lights had also stopped working. Only when I disconnect the wire going to fuse box from the battery, the info center comes to life.
Re: Couple of electrical problems
Posted: Tue May 19, 2020 7:33 pm
by MisterH
Maybe its time to replace the fuses? The pop ups I have fixed were to do with the relay needing some WD, but this is very odd how the whole car is 'dead'. I don't know if the car has something like this, but is there a sensor to tell if the ignition is on, thereby telling the car to fire up the instruments?
not a mechanic but just trying to think why this is happening, but pretty sure Brinkie will know
Re: Couple of electrical problems
Posted: Tue May 19, 2020 9:01 pm
by brinkie
1986/1987 cars have VERY flaky electrics, they were the Volvo mechanic's nightmare. I once worked on a 1987 car, which had all sorts of strange failures (engine did start, but no brake lights, dashboard dead, etc.), turned out to be a bad socket of the "15" relay supplying power to the rail that is carrying 12V with ignition on. Those model years can have all sorts of electrical gremlins, especially if they have been sat for a long time in a moist environment.
So what you need to do, is measure voltages. Start at the fuse box, is there a voltage present when it should (with igntion on), is the fuse not blown? Work methodically, eliminating causes.
Re: Couple of electrical problems
Posted: Wed May 20, 2020 6:12 pm
by Fox
brinkie wrote: ↑Tue May 19, 2020 9:01 pm
1986/1987 cars have VERY flaky electrics, they were the Volvo mechanic's nightmare. I once worked on a 1987 car, which had all sorts of strange failures (engine did start, but no brake lights, dashboard dead, etc.), turned out to be a bad socket of the "15" relay supplying power to the rail that is carrying 12V with ignition on. Those model years can have all sorts of electrical gremlins, especially if they have been sat for a long time in a moist environment.
So what you need to do, is measure voltages. Start at the fuse box, is there a voltage present when it should (with igntion on), is the fuse not blown? Work methodically, eliminating causes.
Yes there is power running to the relay box, and the pop up lights were caused by a blown fuse, so no biggie. Should I look into replacing some relays? If so which ones?
Re: Couple of electrical problems
Posted: Wed May 20, 2020 10:19 pm
by Murf
I had an issue with my GT where the info centre was very faint and the radio didn't work. It turned out that the fuse carrier in the fuse box was faulty and was only allowing 6 volts to pass through.
Check the voltages at each of the locations that are faulty and see what you get.