wire digram for aircon

[Jinx Reyneke]

Rough stony roads take their toll. With aircon working used the indicator. the aircon fan in cab gave a few surges in time with indicator and no more aircon. And shortly after no more indicator either about 5 uses later. Took it to a auto electrician. Replaced flasher relay and aircon relay and a inline fuse for aircon. Happy days Then it happened the next day and back to auto elec. Now I'm back in the bush no auto elec, just me trying to trace a web of wires.

I have found indicator flasher unit and aircon relay both shot. Replaced them. all working again but why is it blowing them? With a tester I have found a black wire from aircom relay going to an earth but it has 13V I tested from a good earth to this black wire separately and found the 13V, why would you connect power to the chassis? If you take the wire off the aircon stops working.

Could someone help me out with a wiring diagram of how it should be.

Thanks a bunch

[western]

Book 5, Section 82 for Air Con & associated wiring diagram.

[Dave W]

It sounds as f the earth point isn't connected to earth anymore. As a result the aircon relay is trying to earth through the indicator relay and the indicator relay through the aircon one. Your description of the original fault is a classic earth problem.

If the earth point isn't connected you will get up to 13v at that point, fed through the aircon/indicator relays. You can probably resolve the problem by running an earth wire from the dodgy earth to a known good one and/or finding out why the earth is bad. It's not that 12v is being fed through the chassis, it's actually the fact that the earth point isn't connected to earth that is causing you to see a voltage there.