(T) Unfixable AC Air Conditioning ECU problem

Hello all

Have a 13 Lounge who's air conditioning stopped working last summer. My regular mechanic checked the gas and all was fine so suggested I take it to an AC specialist. AC specialist said they couldn't find any problems and said it was probably a programming or electrical fault so take it to an ECU specialist. Took it to an ECU/electrical specialist who said they can't find any problems. They bypassed the switch and it worked while they had their machine attached but couldn't understand why the ECU wasn't switching the switch on.

Out of sheer desperation has anyone had the same problem?

Obviously I don't want to take it to FIAT because of the expense but also I've had VERY bad experiences with them over a few electrical faults

All the best

Nicky

Start with the basics does the light switch in for the Aircon when you press it?

It’s certainly not something I have heard of before.

In years gone by the high pressure switch and low pressure switches in the system where all connected in series, so if any switch wasn’t in the right state the aircon wouldn’t work.

The only connection to the ecu was to tell it to up the idle speed.

Now the ecu takes inputs from all these sensors, has control over the compressor clutch and can read the exact pressure of the gas.

Without knowing everything that’s been done, what has or hasn’t been tried and what the specialist bypassed to get it to work it’s hard to say what you can or can’t do or where to start.

Essentially if it’s an ecu problem then you’re electrical specialist should have been able to fix it, unless they didn’t want to, too much like hard work. The only thing you could try now is a new ecu and that’s not going to be cheap. It’s certainly something the ecu specialist should have offered as a solution, I’m guessing he didn’t then I’d guess he was not convinced himself this was the fault.

Maybe it’s worth replacing the heater controls panel. You’ll find one on eBay cheap. Easy to change. It could easily be faulty circuitry within that. If it is, it’s a cheap easy fix. I think that’s worth a try.