Alternator derived transmission issue . . . again

Very good to know about this problem. It makes perfect sense though, and I'm glad you got it fixed!

Asinnn wrote:

Hi Everyone,

Thank you for all your help with the Riviera. And a special "Thank you" to Lance. Without Lance's help in obtaining a thermistor, the Riviera would still be parked. Yes, swapping out the thermistor certainly cleared up the shifting issue. Junkyards in my area do not keep complete cars for very long and I had no luck locating a thermistor locally.

This time the only thing affected was the shifting. When the alternator went bad a couple of years ago, shifting, the ac/heater controls and digital readouts on the dash all went haywire.

Attached are photos of the old thermistor cut open to show the internal chip. Unfortunately, it broke in the process. I have tried contacting one Thermistor supplier but it didn't look like anything they offer.  He didn't think it was a thermistor at all until I sent him the pages from the GM repair manual. So, finding spares in junkyards seems to be the only solution. I am also attaching another image which talks about testing the thermistor and lists the GM cars that used them.

+1 Thank You to Lance.

For people in the future that have this problem: If you can copy the numbers off of the thermistor body you can replace it using a cross-reference; if you use the info in the Thermistor thread on this site you can get a superior replacement. The replacement does not look like the original all that much... and it does not have to.

Albertj