I did I search on the forums on this, but Im gona beat this one to death a little more. I drove my 96 SSE to work yesturday and the heat worked no problem. Car sat over night at work (rained all night) and I drove it home today. Car heated up like normal, but the vents blew out cold air no matter what I did! It would blow colder if I kicked the A/C on, but heat was maybe about 45-50 degrees F tops. I tried burping the coolant system, but got no air out of it and I let it run for a good 30 mins or so with the cap off. Iv regularly changed the coolant so I dont think theres any gunk in there. Any other ideas why the heat would crap out all of a sudden? Thanks a lot!

If both of your heater hoses are hot, then the heater core is more then likely working. I'm thinking the actuator is not moving. I think Billboost did a write up on that.

couple links that may help:

A/C Service Tech Tip: How to redirect the cooled air in late model GM cars

and

http://trialsnuts.com/ecc.pdf

both very helpful

Ok ive finally pin pointed that the air mixer is shot. The temperature is now flashing every morning when the bonneville is started and no hot air or very little. Do someone have the link with maybe a step by step replacement procedure on a 96 bonneville? I cant seem to find one by doing a search. Thank You in advance.

You can try this thread here. It may have the info you need. There'* several broken links that need to be fixed. I'll talk to venom about that.

https://www.gmforum.com/t217162/

I was in the same boat as you a while ago. So this is what I did in the mean time before I had enough money/time to fix it correctly.

I disconnected the airmix actuator from the blend door rod going to it.

Easy once located just give it a nudge up and it will pop off the plastic clip. Than this way the air mix blend door defaults to full hot. This is good because now you will have heat in the winter time. But it is FULL hot and if you drive for a long distance you will get really hot in side the car.

So what I did next is replaced my 195 stat with a 180 stat for the winter. The car heats up good and the cabin inside is very comfortable. But mind you this is not a permanent fix just to get you by.


So to get to the airmix actuator rod remove the glove box liner..should be like 4 screws. Than look down the hole on the left to see the top of the actuator and pop up the rod. good to go full heat. If too hot than swap out your 195 stat for a 180... I'll dig up some photos of the glove box/air mix area for you.

Todd.

Thank You guys, where can I find the air mix actuator? I tried Autozone and Advanced Auto and neither of them have it. Is it a dealer only item?

I bought mine through Auto Parts Fast at RockAuto
It was something like $56.00 shipped and some change

try this link:
RockAuto Parts Catalog

part number 1571835