hello i just installed a serpentine belt on my 1990 camaro. the compressor only had 1 wire. i installed the positive wire to it. that wire runs to the back of the ac controls. i think it was green if i remember. i installed a ground wire to a screw on the compressor. not sure it was needed but yall can see in the pictures. im not getting any power to compressor and the blower fan isnt coming on. if i run a wire from positive terminal of battery to the wire on compressor it comes on so there has to be a relay somewhere. anyone got any ideas or location of this relay? also im posting a picture of a relay next to the accumulator. is this what im looking for?

 

The relay you're looking for is on the driver side firewall.
The one in your picture is the relay for the fan blower motor.
The driver side firewall typically the one closet to the fender is the relay you're after.

You said you ran the positive for the compressor to the green wire at the back of the ac controls?
Or do you mean you connected to the green wire for the connector that used to plug in the old R4 compressor?
If you ran to the back of your ac controls you bypassed the high and low pressure switches.

 

Sounds like you have the classic problem involving the incredibly STUUUUUUPIDDDDD design of connector that GM used in cars from the mid 70s until well into the 90s.

Remove your AC control head from the dash. You will find that it has 5 wires coming off of the switches that go one way (harness for compressor and blower resistors), and one brown wire coming off of the "mode" switch that goes another way. That brown wire supplies power to the entire HVAC system. Follow it up into the dash, maybe a foot or 15" or so. You will come to a connector. This basically plugs the HVAC subsystem into the "car" proper, via the dash harness. You will find that it is BURNT TO ASHES. It contains one of the absolute worst possible design features that a connector can incorporate: the plastic housing maintains (or fails to) the tension holding the connection together. As anyone with 2 neurons they can rub together and get at least ONE to fire, hell EVEN ME, can figure out, once the THERMOplastic (thermo = prefix that means that the plastic is heat-sensitive and is formed during the mfg process by melting and can be melted at any later time if the temp exceeds whatever its melting point is) shell of that connector melts from the heat generated at the connection, the force holding the connection together is reduced. When the force is reduced, the connection gets worse, and generates more heat. When there's more heat, the THERMOplastic melts more. When the THERMOplastic melts, ... no doubt you can see where this is going. Furthermore, as the connection worsens, even MORE heat is generated, which causes corrosion on the metal parts, which generates more heat, which accelerates the corrosion, which ... you can see where THIS is going too, no doubt. All in all, a disaster biding its time to fail in EVERY GM car of the era. At one time (maybe early-mid 90s) I and my immediate family owned about 7 or 8 such cars; 5 of them at nearly the same time had either the connector failure that your car has, or the same failure in another connector of the same design in the same system which feeds hard battery to the blower high speed relay. That one is in the engine bay, about right above the pass side valve cover. Since these are part of, and unique to, the HVAC system, it must have been a Harrison Radiators thing; maybe they can design radiators, butt they clearly don't/didn't have anybody that knew electricity.

Here's what that other connector looks like when it burns up. I don't have a pic of the specific one that's burned up in your car, butt you may be SURE it will look alot like this.



Once you find that connector, cut it off and replace it with a set of the BIG FAT WIDE slide connectors for #10 & #12 wire (yellow insulation). You might have to fold the wire back on itself to get it to crimp well. Not, the little weenie yellow-barrel connectors that are the same as the red- and blue-barrel ones; I'm talking, the BIG FAT WIDE THICK kind. At least twice as much metal as the others. If you can find insulated ones that's the best thing. If not, cover them with some hi-temp sleeving and electrical tape to keep them from touching anything.

 

Incidentally the problem is NOT a relay. There is no relay that can disable BOTH the compressor AND the blower. The ONE thing that CAN however, is the connector in the brown wire under the dash, which when it fails, breaks the power feed going to BOTH of those things. Well, and also maybe the "mode" switch, butt that RARELY goes bad. Start with the connector.