I drive a 1992 Opel Monza 1.6 GSi (South Africa), which is the equivalent of the UK's Vauxhall Belmont with the 16SE engine.
A few months ago, I had the problem that one of the relays in my fuse box would start buzzing whenever 2 or more of the following were on: indicators, reverse lights, brake lights.
It would also happen when the cooling fan came on, but this was fixed by hooking up the fan's power directly to the battery via a relay and a 30A fuse.
This problem has now started again, and it feels like the flasher relay buzzing.
There would be no buzzing when the air-con was on. I suspect that this is because the air-con is also earthed when it is running.
Also, whenever I hit the brakes immediately after start-up (from cold), I hear a clicking noise because the air-con switches on for a split second.
I suspect that the afore-mentioned lights aren't earthed properly.
My question is: WHERE ARE THESE LIGHTS EARTHED ON A BELMONT/ASTRA???
Also, what else could the problem be?
I've already checked that all the relays and fuses are plugged in properly. The alternator was overhauled last year. The earth strap to the battery is fine, as is the battery.
Only the above-mentioned lights are affected: Everything else works perfectly.