89 vette heater

The heater on my 89 vette doesn't work and it's cold out there! Blower works, coolant hoses are warm to touch so that's not the problem, A/C works fine, but only cold air comes out of the ducts with the heater on. Any suggestions? Is there someplace I can see a schematic of the system to point me in the right direction?

I have the same problem with my 89 Vette. If you felt the heater hoses and they are hot you more than likley do not have air in the system. These models sometimes need to be blead at the small hoses going to the TPI and intake.
If the hoses are hot at the heater core, the problem might be at the programer or temperature valve actuator valve. I will let you know when I work on mine on Friday.

Let me know if you hear from anyone else.

Thanks, Jim

I have the same problem with my 89 Vette. If you felt the heater hoses and they are hot you more than likley do not have air in the system. These models sometimes need to be blead at the small hoses going to the TPI and intake.
If the hoses are hot at the heater core, the problem might be at the programer or temperature valve actuator valve. I will let you know when I work on mine on Friday.

Let me know if you hear from anyone else.

Thanks, Jim

Thanks for the input, Jim. I am continuing to poke around with it. If I figure anything out, I'll let you know and I look forward to anything you find out. My instinct at this point is that the mechinism that directs the air for cooling or heating is malfunctioning. But I don't know enough about the specifics of the system to pin it down.

So far yours is the only reply.

Thanks again, Steve (islandVette)

I had the opposite problem. It was a cold day, so I put on the heat. The next time I drove it, it was a hot day and the heater stayed on and the ac wouldn't work.
I removed the passanger side access panel to gain access under the dash. The little plastic retainer for the heater flap came loose. I zip-tied the linkage together and it works just fine.

I had the opposite problem. It was a cold day, so I put on the heat. The next time I drove it, it was a hot day and the heater stayed on and the ac wouldn't work.
I removed the passanger side access panel to gain access under the dash. The little plastic retainer for the heater flap came loose. I zip-tied the linkage together and it works just fine.

Thanks, Texas, I'll take a look.