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Im trying to get the HVAC head unit to function for the heater to work before replacing the locked up compressor. It displays and isnt dead or dim like other hvac problems i've read. The codes it throws are "short to ground left/right actuators" 5 codes i believe with those both being two. Im assuming a short to ground for the actuators is that the problems in the hvac head unit? It constantly reads 69 degrees even when its 80 degrees outside.
Last edited by Justin Raney; Nov 5, 2021 at 06:19 PM.
Great thanks i believe it had a code for the outside sensor which to me looks to be the original and head unit stays at 69 degrees. Amazon has the ac delco for 7-8$.
Last edited by Justin Raney; Nov 6, 2021 at 07:45 PM.
Well picked up the new sensor from autozone but the original pigtail had both prongs from the old sensor broke off. I had used a pigtail off a 2008 junkyard saab i had laying around for the ambient temp sensor the pigtail was the same. Haven't driven it yet to see if it works but hopefully does the trick. The wiring does feel old and brittle so hopefully nothing wrong with the wiring up in the harness. It should reset after a few miles if all is well according to the other thread link posted above?
Here are the HVAC codes any help is appreciated. Great B0333 C is the outside air temp waiting on it to arrive at the local autozone.
U1064 H
U1096 H
U1160 H
U1255 H
B0333 H C
B0361 H
B0363 H C
B0365 H
B0367 H
I believe the U codes are no communication, and the BO 360s codes sound like you need new vent door actuators. The internal plastic gears are pressed on the metal shafts, and when the plastic gears get old and brittle, they usually split in half. Presto, no more press fit!!! These are supposed to direct the correct temperature air to the selected vents, but can't when they're spinning on the shaft. Hope this helps.......
Does anyone know if theres a way for it to show or view the internal cabin temperature via the cabin temp sensor or is that not viewable and only a sensor that controls the AC thermostat settings?
Ok great got the hvac unit to power on orbut does anyone know if the default mode or blend air system or what the problem could be when it directly blows the air out the passenger vent as well as defrost and front vents. It powers on but trying to get it to power thru the vents other then a light breeze and blowing air out the vent next to blower motor. The only codes are B0361 B0363 B0365 B0367. I read above the actuators are electric driven or vacuum driven? Its coming along one piece at a time. Great thanks for the help guys. It does seem to blow air out the front ducts and straight out that passenger duct but the car does have a locked up compressor that needs replacing so i may get to that with an ebay 160$ compressor kit. I do need to check that theres no holes in the vacuum line from behind the intake.
Im curious as with this HVAC is there a way to operate the driver and passenger with 2 different operations being ac and heater at the same time? I only ask as it does have a passenger and driver temp ****. I have the first 4 codes as described in this and with both temps driver/passenger ***** on heat they dont blow any hot air. So im guessing im having problems with the temp valve blend actuator for both left and right? Is there anyway it could be a short circuit in the head unit or is it possible for both left and right to quit.1997-2004 Corvette Temperature Valve/Blend Actuator (zip-corvette.com) Im going to test the plug to see if it gets 5 volts and maybe remove one and see if its in bad shape.
EDIT: I see the actuators are tucked up in there and require most disassembly of the dash. If anyone has changed both left and right actuators without removing a bunch of stuff please comment on how you did remove/replace them as it would be a great help. There's cheaper replacements from rockauto for the actuators 20$-30$ and the newer style i believe. How hard is it to convert it to a manual climate control setup? Would require a whole different ac/heater box?
Last edited by Justin Raney; Nov 17, 2021 at 06:26 PM.
Vettetronics on ebay led light repair when i asked about this told me if that one actuator was bad or didnt calibrate into place then the headunit wont send out the blower motor signal sometimes and itll just turn on randomly.
That may be the issue as i was going to swap the headunit out and check for power at the wires looks like ill look into the actuators being the issue.
A lot of your symptoms are classic broken vacuum line results: https://www.corvetteforum.com/forums...with-pics.html
Coupled with a dead compressor it becomes very difficult to determine which way to go first. Try to follow the vacuum line from the back of the intake manifold over and down to the vacuum reservoir. It gets blended into the wiring harness, but is very likely broken along the way.
Maybe i checked the ones from canister to cabin but should recheck them.
I need to replace some dorman actuators on both sides 77$ each from amazon the one piece plastic or if the cheaper rock auto skp,four seasons are just as good those.
Heres what i was told about the blower motor signal if actuators never calibrated or were bad. Mine has codes for both.
Sometimes, if there is an issue with a faulty blend door actuator, the head unit won't sent a signal out to the blower control module. It will keep checking the position of the blend door actuator until it is satified or will give up after some amount of time and then the blower will start working again at an alomst random seeming time.
A lot of your symptoms are classic broken vacuum line results: https://www.corvetteforum.com/forums...with-pics.html
Coupled with a dead compressor it becomes very difficult to determine which way to go first. Try to follow the vacuum line from the back of the intake manifold over and down to the vacuum reservoir. It gets blended into the wiring harness, but is very likely broken along the way.
I fixed a small hole in the line by cutting and really short pushed together rubber coupler but didnt see anything broke.
Is there a tool or machine you can run smoke thru to see where the leak is or if a line is broken simular to intakes, turbo piping and for finding vacuum leaks?
As with all things, if we look for it, someone on YouTube will show us how to do the job with stuff already in the garage: https://m.youtube.com/watch?v=EhNQiIRsCCk
Theres got to be an affordable smoke machine to test for vacuum/ air leaks as this type of situation is common.
I really just need a cheap one that works. Autozones 12$ fluid transfer pump 1 qt 5qt jug diff, trans or other fluid transfer pump sure works nice for filling the auto trans on rhino ramps.
Not sure when i looked the canister was there with the check valve and lines to cabin back of the intake. I think i may have tried blowing thru the one from the intake to the canister to make sure it didnt have any leaks. I may not have. Would this be the easier way and which line on the canister goes to back of intake and cabin?
Pull the line off inside the cabin with it running see if its sucking any air and blow thru test it as well? These tricks should work.
HVAC head unit problems
