gen3dreamin

Hey guys i have a 2000 ECSB w/ a 4.8(for now) and the a/c - heater control head took a crap on me. When i replace it do i need to get the new one calibrated? Thanks for the help guys. Also, are there any updated calibrations for these that i could maybe try first?

LowBlack99

iTrader: (3)

Your good, plug it and and go. If you have a problem unplug to 30a HVAC fuse on the side fuse panel and leave it out for a few minutes.

Whats it doing? Not switching the vents or not cooling?

budhayes3

iTrader: (19)

+1 No calibration necessary. As asked above, are you sure you need a control unit? Blend door actuators are real common failures on our trucks.

gen3dreamin

The actuators seem to be working fine, at least the ones i can get to fairly easily. The a/c will work fine when i first start driving it, then after about 5min it will stop blowing cold. Freon levels/pressures are good, i replaced the high/low switch, and the compressor seems fine when it turns on. Also if I try to switch it to heat it wont switch and the compressor will continue to kick on, as if it were still set on a/c. Only thing i can think of is control head. Any other suggestions?

budhayes3

iTrader: (19)

Could be the control unit, but it may still be something with one of the actuators. You could try the actuator re-park procedure just for poops and giggles. Search this section for re-park procedure or pm Torque_Wrench, as he's posted it up before.

gen3dreamin

Cool, cool, thanks for the help, and quick responses. It is greatly appreciated. Ill give the park procedure a try and let ya know what happens.

RST787

Whats a blend door actuator? My driver heat occasionally decides to come on when the ac is running but returns cold when i turn it off and start her back up

AJII

iTrader: (7)

Bumping this because I'm having ac/heat problems that are similar.

When I turn the heater on, it won't go off 75% of the time. And in the summer, have to press the ac button several times to get the compressor to kick on.

Any idea what the problem is? I've replaced the control unit with no luck.

Thanks

Superado

iTrader: (37)

drained radiator of water and added anti-freeze last night...
ran truck with heat on for maybe 10 minutes...circulating fluids...
warmed the truck up this morning and on the way to work I noticed that I could not change heat from "face" and it was on "floor" already...no matter what setting I put it on...blowing from "face"...
also, I couldn't turn temp down...HOT only...
also, I couldn't press the in-cab recirculate button and turn the vent off with blower off as usual...
ALSO, I couldn't press A/C button and turn on compressor...
have experienced issue similar to RST787 before and bought a blend door actuator but never installed it because it just didn't happen that often...still have it...
BUT...my symptoms this morning don't sound like the actuator ...or DOES IT?

budhayes3

iTrader: (19)

That doesn't sound like the common actuator problems, but anything's possible. If an actuator was shorted I'll bet it would cause some wierd things to happen...my *guess* would be the control unit in your case, but that's just a guess. I'd start with checking all of the fuses...do you have a friend with a similar truck that you could swap control units out of to see if that's the problem?