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Got the axle from Jim Finn today. Packaging was excellent. It came in a box like you would expect to see if it was shipped from GM. Jim has been very helpful every time I've called on him for assistance or parts.

Since Ronnie's tests were with the engine not running, somewhat lower voltages would be expected, especially over time. I do not know what the GM engineers have designed into the system, but I do know that I, and others, have commented on the unobtrusive nature of the climate control. I run mine in ECON a lot, even when temperatures really need A/C, but I don't use it for short trips. I notice the fan more at times like that as the system tries to bring down temperature using only airflow to accomplish it. I think they did a good job of using the best combinations when in full auto mode and staying in the background when doing so.

Ronnie, thanks so much for doing the "field" test on this. I am away from the car right now but when I get back to it I will have to duplicate your tests and see what my results are. It is odd that the max heat and max cool numbers are where they are. I had been doing my tests with max cool. I wonder what the econ numbers would be. It's perplexing to be sure.

Runs for a second and dies sounds more like a fuel issue. What is the rail pressure doing ? Needs to be at least 30 psi.

Depends on which adapter you used, some are pretty bad.. I like the later Nulaxy products, about $30 on Amazon.

2seater and Ronnie you are both pointing to the same place, the control module, as I suspected. I hate to think that I am out $140 (because the part is not returnable but that seems to be where I am heading). I deeply appreciate all your assistance with this. If you have any more thoughts or suggestions, I am open to any and all.

We're getting nowhere with theory so I decided to do some hands on testing. Without starting the car and with the fog lights off, I turned the key to run and let the brake pump run till it stopped and turned the key off. Then I connected my meter to ground and the purple wire going to the blower motor. I turned the key back on and selected the climate control screen on the CRT. Below are the readings I got. Ambient temp in my garage was 73* It appears when testing in AUTO mode that the fan speed voltage is being determined by readings from all the sensors such as ambient temp sensor, sun load sensor, etc. My car was in the garage. I suspect the blower voltage would go to full battery voltage if the car was outside on a hot day in full sun when the temp was set to maxcool. ECONj mode fan speeds: Low speed= 4.16 volts Hi speed= 10.29 volts Auto= 5.36 volts AUTO mode temp settings: 75* (default after battery disconnect switch closed)= 5.38 volts 65*= 7.94 volts maxcool=8.64 volts (now I went the other direction for heat) 80*= 6.13 volts 85*= 8.86 volts maxheat= 8.64 volts <- actual voltage. not a typo. odd that voltage dropped on maxheat.

The later models might be different but below is what the '89 FSM has to say about how power is supplied to the blower motor. I -think?- it supports what I said in my last post if I stated the point I was trying to make in a way that makes sense.

The engine starts on commands from the ICM and then switches to ECM control of the timing after it starts. I think the problem lies in the wiring between the ICM and ECM or the PROM and ECM combination. The two common elements which have not been replaced is the wiring and the PROM. Checking the wiring for continuity or cross talk is straightforward with an Ohmmeter and a long jumper wire. It can be done alone but a helper makes it much easier. The color codes at the ICM and the ECM are the same and am pretty sure all the relevant connections at the ECM are in the 32 pin black plug. A loaner Prom and/or ECM w/Prom as well as the wiring check have been suggested before.