AC Vacuum Pump and Oil

[Dynomite]

Originally Posted by vilant

Here's the fuse block on the passenger side. The 2 fuses are 15A CTSY fuse and 25A A/C fuse. The clutch relay should be fed from 25A. Not sure why you have a 10A for CTSY (if that's what you're talking about).

The fans (heater/air) do not work either as they stopped at the same time I lost power to the Pressure Cycling Switch.

I think everything else is working as far as I know. The Heater Controller on the dash I prolly messed up by jumping the Pressure Cycling Switch too many times in succession

I have an extra Heater Controller from a 90' Corvette that looks identical...which I may just switch as an experiment.
That switch should take an hour and then I can eliminate the Heater Controller as the issue. I will take a picture tomorrow of that experiment.

The lesson learned will be.....do NOT Jumber the Pressure Cycling Switch to get the compressor working but rather hot wire the compressor at the Pressure Cycling Switch connector (12 volts directly from battery to A/C Compressor) after determining which lead at the switch goes to the A/C Compressor.

I was going to check the A/C Clutch relay but thinking on it....that would not effect the Heater/Air Fans.
Is your schematic a 90'?

This is a 91' passenger side fuse block...I have a 15 amp for CTSY and a 10 amp fuse there for AC

[vilant]

All information and pics are from the 1990 Section 8A Electrical Diagnosis Supplement. I can't say what is needed for anything after 1990 ( but I assume 91 should be the same), but on a 1990 there should be a 25A fuse, not 10A on the A/C fuse space.
P.S. If you look on pg 8A-66-1 of the pics I gave you, you'll see there's a 5A A/C underhood fuse on the line that gives input to the heater/ AC programmer from the output of the blower power module. There is also a fusible link that feeds the blower control module. If the link is completely blown, the blower will not work (I'm assuming the heater programmer will not work properly without input(voltage) from the blower power module output, which is protected by the 5A fuse).

[Dynomite]

Originally Posted by vilant

All information and pics are from the 1990 Section 8A Electrical Diagnosis Supplement. I can't say what is needed for anything after 1990 ( but I assume 91 should be the same), but on a 1990 there should be a 25A fuse, not 10A on the A/C fuse space.

P.S. If you look on pg 8A-66-1 of the pics I gave you, you'll see there's a 5A A/C underhood fuse on the line that gives input to the heater/ AC programmer from the output of the blower power module. There is also a fusible link that feeds the blower control module. If the link is completely blown, the blower will not work (I'm assuming the heater programmer will not work properly without input (voltage) from the blower power module output, which is protected by the 5A fuse).

5 amp A/C fuse is in fine shape.....Heater Controller was switched with no effect.
I now have power to the A/C Pressure Cycling Switch.
No fan response on Heat or A/C. I have not located the fusible link.

I took a peak at the Fan Wire Harness and in the process am re-routing the HVAC Wire Harness to a better location.

Guess what.....
When I installed the engine there was ONE SINGLE ground wire not connected up from Wire Harness at rear of engine.....Guess which one

I connected that ground wire through my ohm meter to the black wire on fan connection ....and.....zero ohms

[vilant]

Glad you got it figured out. I didn't notice the number 10, written below the A/C fuse, the first time I looked at the pic. I looked at my A/C fuse space and it has 25 below it. Guess that's something else that's different on 90's then the later year models. Which probably means the drawings are only relevant to a 90, nothing later (probably no fusible link either, on later models). Would you like me delete those drawings?

[Dynomite]

Originally Posted by vilant

Glad you got it figured out. I didn't notice the number 10, written below the A/C fuse, the first time I looked at the pic. I looked at my A/C fuse space and it has 25 below it. Guess that's something else that's different on 90's then the later year models. Which probably means the drawings are only relevant to a 90, nothing later (probably no fusible link either, on later models). Would you like me delete those drawings?

Absolutely not (do not delete the drawings).....that is a great reference and if not exact...very close. Even the color wires. Thanks......and yes....there are differences here and there between the 90' and 91'. Since I have both, your drawings are very relevant

Fans are now working but had to attach that fan ground wire to rear Plenum bolt where I can get at it

Cliff