When the AC is on and I get on the brakes hard it
turns hot. If I turn the switch to off for about 5 seconds
then back to AC it immediately blows cold. I've checked
the vacuum check valves and they are fine. The blend
door is electric so this is where I'm stumped.
Any ideas.
Thanks for any help.

 

SoCal desert? Argh, you WANT your a/c to work right. Wonder if the temp door is flopping around...... Drop the little electric motor, and look at the coupler between the motor, and the axle for the blend door, bet its cracked.....

Heatertreater.net.

 

Thanks man. I was thinking about that, I'm sure I have that issue as
when I move the temp control it's either hot or cold, no in between.
It just doesn't make sense that a quick off and on with the control ***
switches it back. I really had not wanted to try to get to that 3rd screw.
I'll give it a shot and let everyone know.

 

Is the AC clutch still spinning when it goes hot or is it stopped? Could be a worn clutch disc.

 

HeyYou, where is this little motor you are referring to sir? I'm going to drop my dash and install new dash but I might be having trouble with my door as well. Did a coolant flush and when i tried to run defroster it stayed cold instead of getting hot. I may be having a heater core issue too but I need to flush that a little better.

 

Yours is cable operated. (temp door) The little motor showed up in 2000, I think. (maybe 99, but, not 100% on that....)

You probably have an air pocket in the heater core. These trucks are a major pain to get all the air out of 'em.

 

I believe it was 97, All kind of issues with them. I'm glad i got a cable. Drill a small hole in the thermostat, That will allow the air to get out when you are filling it and solve the problem of air in the system.

 

Not the heater core. That thing hangs onto its air pocket like a miser hangs on to his last coin.