I was helping a friend fix his 1990 Old Delta 88 today. He wasn't getting any heat at all. His temp gauge would only get to about 130 degrees. So, I replaced his thermostat and it now gets to 185-210 degrees. Then, I noticed his blower is working intermittently. On the High Fan Speed setting (Automatic Climate Controls) the blower hardly works. Sometimes, it will kick in for a few seconds on high, then goes right back to its low setting. So I think the blower is ok, but is this a sensor issue? Since I changed the thermostat it does blow hot air but still not at the correct speed. Any help would be appreciated!

1990 Oldsmobile Delta 88

Well, on those older Deltas there is a little door located around the middle of the firewall with 4 wires sticking out of it. Behind that little door is a servo that controls the entire climate control system. Try changing that and it should help! Good luck!