Onlya1

I know this has been asked before but where is the A/C relay on my 87 vette? Help Please!!!!!

SunCr

If you mean the compressor, there isn't one. Electronic Air uses a Blower Control Module - mounted on the Evaporator Case - that grounds the clutch coil based on a low voltage signal from the Dash Controls. If it's Manual Air, the circuit from the a/c fuse flows through the dash controls, out to the low and high pressure switches and onto the coil. Coil is grounded to the frame. If you mean the Blower Motor, Manual Air has a relay above the Blower. Electronic Air uses the Blower Module and doesn't have a relay.

Onlya1

I ordered a A/c blower relay from mid america for an 84-87 vette and I recieved a relay with this part number from acdelco 60207546 and it says relay, ac blower, I'm confused.

Bobby

SunCr

Post whether you have Manual or Electronic Air. Is it the Blower motor you're having problems with or the compressor? AC Delco part #'s and what they fit are available at www.acdelco.com

Onlya1

I have the electronic control for the A/C and heater. I can change the temperature up and down for the heater and the A/c but the blower doesn't come on nor does the blower. I checked the fuse above the blower and the fuses in the fuses box. Is there any other places I should check for fuses links or fuses?

SunCr

Blower is controlled by a Module mounted on the Evaporator Case. It gets low voltage signals from the Dash and amplifies them to control the speed of the Blower. If you haven't done so, jumper the blower motor to the battery to make sure it works. Then check for Battery Voltage at the Module - Red Wire. It's on a fusible link, so if it's not there, you'll need to find the link and replace it (you will have to trace it to behind the battery). If power is good, check the low voltage signal wire from the Dash to Module at the Module. It's Brown or Tan and should have 2 to 2.5 volts with the setting at "1". The output or Purple wire should have about 4 volts at this setting - so check it for that voltage. If the controls are at "10", the signal wire should have at least 6 volts, the Purple wire 12 volts. If you have the signal voltage, but no output, replace the Module. If there is no signal voltage, you'll need to tear into the dash and remove the Dash controls so that can ohm at the Brown wire. If good, you'll need a new assembly. Modules are available through Chevy, Pontiac, Buick or Cadillac - GM uses the same across all lines. NAPA also offers it. The assembly is available, rebuilt, at the Last Detail - www.tld-corvette.com - though even rebuilt, it's pricey.

SunCr

PS - check the ground too - Module and Blower are spliced, sharing the same ground.

vader86

The blower motor has its own relay, and theres another AC pressure switch mounted on the compressor.

Sounds like you have just the blower relay.

Onlya1

Thanks to everyone for the info I'll try it all and post a message with the results.

Onlya1

Phase 1 - jumped the blower motor to the battery the blower works.

Onlya1

I jumped the blower motor and it works then I checked the voltage at the module at the red wire and received the right reading from there I checked the voltage at the purple and received the right reading but on my car I don't see a tan or brown wire I see a black, black/red, green/yellow, purple wire. No voltage is coming from the other wires on the module. The red wire is on a seperate connector with a green wire. The other four wires is on the same connector black, black/red, purple, and the green/yellow. Is the black a substitute for the tan wire?

SunCr

Now that you mention it, I believe the Black/Red is the output to the Blower Motor on your Year. Whatever color is hot (Not Black) at the Blower, should be the same at the Module. Green should be compressor Ground. Green/Yellow, compressor "On" signal. Black, Module Ground (and it's spliced to the Blower Ground). So Purple should be the input from the Dash. If you have the input, but nothing at the Blower Motor, the Module is bad. Be sure to check the Module Ground by ohming out the Black Wire from the Module connector to the frame - that way you'll also verify the Blower Motor Ground.

Onlya1

I checked the black/red wire and it goes to the blower also but there no voltage at the blower. There is a signal going to the compressor. I will change the module tomorrow and post the results, thanks!

Onlya1

Thanks for all the help. I ended up sending the climate control to be repaired. I should have it back next week and working, once again thanks.

hokiess

Where did you send your climate control to be worked on if you don't mind me asking? I may have to do this myself. THanks

Onlya1

OK here are the results I sent the climate control off to corvette dash cluster service in Bloomington, Indiana at http://www.corvettedashclusterservic...nd%20Time.html I received the climate control back with no faults found. I ordered a control module new and replaced it but no response from the blower or A/C. I then had the programmer taken apart and re-soldiered the two transistors and still no response from the A/C or blower. I'm out of options and it's very hot in Texas. Are there anymore ideals to try, Thanks!

Poncho C4

The relay for the a/c heater blower is under the blower motor.
to get to it you have to remove the passenger wheel wall then
just replace the relay and that should do it!!!

Onlya1

Thanks PonchC4 I'll try that next. I finally got the blower to blow but the clutch will not kick in. There is no power going to the clutch. I track the a/c compressor wire to the firewall of the car and now I'm scratching my head again saying what the heck is this??????????

ZumZum

If your not getting any power to the compressor clutch it could be the low pressure switch. Pull off the switch and jumper the switch with the AC controls in the on position and see if that starts your compressor. If it does, you need a new switch.
(or, you're very low on freon)

Onlya1

I jumped the plung from the switch and the compressor did not come on. Is there any other cause for power not getting to the clutch?