No blower, fan, AC compressor power

[Jerryl]

Trying to help a buddy . . . And electrical is not on my list of strengths. Lol

The AC system is completely dead. I have not yet looked at the car yet but have been told that the bliwer/fan/compressor does not come on and the fuse appears to be fine.
No work was done to the car and this started suddenly. Sounds to me like a main feed for the whole circuit?

Looking for some input where to start looking.

 

[Jerryl]

Let me ask in a clearer way:
Is there a main power or round for the AC circuit?

 

[nwarky]

I would start by checking the fusible links that run to the starter. One of the three would supply power to the HVAC circuits that you are describing.

 

[Jerryl]

Thanks.

 

[H2Ogbodies]

Thanks.

There's a factory HD lug style soldered crimp within the engine harness where all the 12V runs meet so checking only at the starter won't help a lot-see if you have power @ the 4-cavity connector on the 12ga red. If that is no good, trace that lead. If it is good, check the brown 12V IGN hot sire going to your climate control panel-it will be a 14ga brown wire. It supplied power to the whole panel. This applies to non-digital panels......I don't have a diagram pinout for the digital panel so hopefully this helps.

 

[Jerryl]

So my buddy is tired of no AC after 2 years.
We still can’t get it to work and here is what we tried;

Both sides of all fusible links have power.
The orange wire at the plug by PS fender for (3 in, 2 out) has power on both sides.
Switched the panel from another car that is known good, and blower did not work.
The AC relay (PS fender) has power at orange wire , and here is where I am thoroughly confused.

Ground the signal side of the relay, relay clicks, nothing works.
Removed the relay and ran a HW from the + of the plug directly to other 2 cavities on the plug, and blower/AC clutch *activate*.
Must be the relay right?

Installed a known good AC relay, nothing works. (BTW: The relay from the 86 and 87 are different)
Probed/grounde the signal side of the relay WITH the relay in place, relay clicks, blower and clutch do not.

I found a few schematics online, but they are far from readable.
Its mid 90’s in Houston, so what’s next?

 

[pajo]

Did you ever got this issue straightened out ..?

 

[Jerryl]

Not yet. Lol
Going to drop the car off at buddy of mine who owns a shop. Like I said: Electrical is not one of my strengths.

 

[mikestertwo]

When you talk about putting a hotwire jumper on the relay, which relay are you talking about? The A/C cutout relay or the high speed blower relay? The only two things the compressor clutch and the blower motor have in common is the A/C control head and the power feed from the A/C fuse. Either the switch on the control head is no good or there is no power coming from the fuse block up to the head. Your sure the A/C fuse is good and the connector on the back of the A/C control head is good? Do you have power on the brown wire (pin "E") on the back of the A/C function switch?