Mitsubishi Repair: A/C system, dodge stealth, integrated alarm

Question
My wife has a 91 Dodge Stealth R/T 3.0L DOHC non turbo Manual (her baby) and it has a cooling problem.

When it's warm the A/C kicks out really well but the engine temp starts to go toward red line (we've never let it get there). If we turn the A/C off it drops back to normal, as it also does if we're driving at slower speeds (50 or below). If we stop, even as briefly as hitting a red light, it drops. It will start to climb again as it accelerates, but sometimes, if we raise the cabin temp to 77F (with outside temps of 90+) it will drop even in 5th gear.

We upgraded the A/C to R-134 and we still have the problem(but we're greener).

We've checked the cooling levels - they're fine. We've flushed the radiator and replaced the filters.

It also, on occassion when it's particularly hot out, will stall out, even when driving - usually after downshifting and gliding into a turn or while sitting at a stop light. But, that usually only happens when we have the A/C off, and it will restart easily with a clutch pop. Not so easily if we're at a full stop when it stalls. As long as the A/C is running, even if it's running a bit high, the car doesn't seem to want to stall.  

The car currently records over 160,000 miles, but it's a rebuilt engine, so there's only about 90,000 miles actual on it. The rebuilt was caused by the dealer (don't ask - bad, bad, story) who, in trying to fix a problem with the integrated alarm system cut virtually every electrical wire (incl. the one to the inside-hood light). That's all fixed now (except, to accomplish this, the car now starts in gear) and the only "unexplained" issue is with the potential overheating/stalling.

Any ideas? It's too late to sue the dealer.


Answer
John,
Better than suing the dealership would be to talk with the service manager and have them work on your car, at their expense, until its fixed.  But if it's been over 12 months since they last serviced the car, that would be difficult.

The cooling issue could be caused by the A/C fan not kicking on, bad air flow across the radiator and/or condenser, faulty radiator temp sensor switch, faulty engine coolant temperature sensor, weak water pump, worn radiator cap, or even your car's computer may be faulty and not recognizing the signals coming from the sensors.  Make sure there are no air bubbles in the coolant system either.
Good luck!