A/C cuts out

[93SHO_2]

The Air Conditioner (and heat and defrost) on my 93 SHO, 3.2 AT cuts out. It works fine at start up and low RPMs, but when I reach between 2500 and 3000 RPM the EATC goes blank and the A/C quits. When I drop below 1000 RPM the EATC desplays properly and the A/C comes back on.

I replaced the low pressure cycle switch on the dryer, no help. Also, I swapped the EATC dash unit with a good working unit (some benefit to owning 2 of these), no help.

Further, while the A/C cuts out, sometimes if I activate the turn signals, the EATC blinks "888" in sync with the flasher ??

 

[projectSHO89]

You don't have an A/C problem, you have a weak electrical system. The EATC just happens to be VERY susceptible to low supply voltage.

Weak alternator, weak battery, or a high resistance electrical connection on either the EATC supply or ground would be where I'd focus. Pay particular attention to the primary battery cables and the connections on both ends.

Steve

 

[MD Ever]

Check your battery cables. I had the same condition and found that the connection at the starter was bad as well as the battery cable had been chaffed were it runs down next to the radiator. When I accelerated and the engine tilted enough to make contact with the cable

 

[93SHO_2]

I removed and cleaned the cables at the battery. When I was removing the hot cable at the starter the plastic cover on the solenoid broke. I replaced the starter. Same issues remain.

A year ago I replaced the heater core. Any other ideas?, a relay (which one)?, pinched wire?

Thanks for the prior posts.

 

[projectSHO89]

....

Thanks for the prior posts.

If you ignore them, you're wasting your time and ours.

 

[93SHO_2]

remind me never to say thank you again

 

[projectSHO89]

remind me never to say thank you again

You're welcome.

However, I did tell you what exactly was wrong yet you asked for more ideas.

I get testy when my specific advice is ignored.

Steve

 

[93SHO_2]

Alternator (regulator)

The alternator was producing some extra juice the EATC didn't like. I suppose that self protection feature of the EATC saved a few hundred dollars by not burning itself out. I miss the days when the voltage regulator was separate, and adjustable, from the alternator. $179 later the new alternator and the EATC are working well together.