The clutch coil connector has a green and a black wire on a 1984 Vette, does it matter which way to plug it to the clutch? Is it reversible? Also according to the FSM, the high pressure switch on the compressor is colored red, one wire type when it was new, now all the switches are two wires, what is the right switch color or type for the early C4?

 

Technically I don't believe that polarity matters but I believe that on most R4 compressors the spade/blade had tab that protruded and the connector was slotted to orientate it correctly. The slot in the connector and the tab would make it non-reversible. I thought that early OE/GM connectors had a molded connector 90°

If you've bought a new connector, new compressor or whatever it's difficult to know what to tell you to expect.

I believe that the connector needs to be orientated correctly for the diode in the connector to function. On the later "off the shelf" coils - is the diode internal to the coil? I've no idea.

Have you bought a compressor a clutch coil or ...?


The single wire switch that's retained in the compressor is the fan switch. The orig GM# 2724279 - you could use that original number and shop on eBay and wait until one surfaces. Is there any NOS stuff elsewhere? Very likely! Use that part # at a trusted parts store or GM dealer and have it researched for a current 2 wire and ask that they confirm!

***You might mention what you've done or bought maybe mentioning brand and part# if you've bought.

I've never done this but I understand the "how to" and the reasoning mentioned in this post by user "HRR" - Not knowing what you're doing or have done or purchased maybe there's information you could use to accomplish a repair.

https://www.corvetteforum.com/forums...post1588311844

 

I 'think' that the coil is basically an electromagnet in operation, so I don't think it matters which way the current flows. Worst case, I would first check the FSM to confirm, but I would expect you could run a couple of wires from the battery to the coil and jumper it without anything else running and see if you can detect any sound or movement when you attempt to energize it.

Just a thought.

 

The clutch itself doesn't matter but there is a diode between the wires and it will blow if reversed.

 

Thank you guys, I ordered a new compressor and it is a Four Seasons brand, currently the old one has a blue cooling switch from the same company with two wires( it seems that is the only one shown for the car everywhere) The connector is the original one with the diode, I believe I can test the diode with the multimeter? This system has not worked for about thirty two years and now I am replacing the compressor/accumulator and filter and cleaning the condenser and evaporator. The connector is not with 90 degree angle but the straight one and the wiring diagram in the FSM does not show which wire goes where at the coil. My main concern is to make sure I have the right cooling switch for it in case I can not find the original one.

 

If you've not purchased yet mention everything to 4-Seasons and get their response and opinion before buying a thing. Buy everything/anything they suggest to keep the warranty intact - they likely have maybe different opinions as to the orifice used dependent upon refrigerant. Mention to them your intent to reuse condenser and evaporator. Buy "LOCAL"!

If they've a suggestion for the switch ask that their suggestion is NO (normally open). I believe I've seen purchases for a NC switch which would create a "FAN ON" at all times.

 

The '84 switch on the compressor which actuates the radiator fan relay is a NO switch. Later C4's which have the radiator fan controlled by the ECM use a NC switch. If you install the wrong switch, the fan would run all the time, except that turning on the A/C might turn OFF the radiator fan!

 

I have asked about a normally open switch but they don't know anything about that, today went to the Chevy dealer and asked about part number 2724279 and they say new number is 89019195( AC Delco 15-2235) it is a two wire kit and that one is the one I am going to get since it has been impossible to find an original one. I tested the diode on the connector and had a reading of 585,.585 or something like that, still need to find out which way to plug it into the coil.

 

I notice on that picture, that car has the one wire radiator fan switch so I assume it has an original switch and the coil connector has two black wires, mine has a green and a black wire, same colors of the connector that plug into the switch at the evaporator line.

 

I wouldn't expect a parts counter guy to know anything about a NO definition for the switch you're looking for. He's not likely to be an electrical expert, or he'd have a different job! Test it with your DVM.

Did you reverse the test leads on your DVM to determine that the resistance of the diode is different in the two directions? If it's not, you have a bad diode, which will damage your Low Pressure Cycling Switch (on your evap. coil). The cathode of the diode goes to the dark green wire. (Cathode----[<----Anode)

One of the wires to my Compressor Clutch Conn. is dark green. Hard to see in this picture (32 y.o. car!). The dark green wire goes directly to the High Pressure Safety Switch. The black goes to ground.

 

When I tested the diode, it had a reading one way and not the other way. Getting closer to finish this task after thirty two years on a non-op a/c system.

 

On this picture, can you tell me if the green wire of the clutch coil connector is the one on the right or the left so that I can orient mine the right way, thank's Jose.

 

Side question but is 4 seasons a good place for AC compressors? I think mine is becoming noisy and if it makes it to the end of the year, I probably will replace it. If so, I think I will revert to R12 since I really don't like the R134A used. In all the few cars I have seen an R134A conversion, they work but aren't as cool as they used to be.

 

The Four Seasons brand is the one most sold by everybody, I sold many when I worked at Advance Auto Parts, bought this one from Rockauto as a kit with the accumulator and filter. This is my first experience replacing the compressor, will post results later, will go the r134 route since is cool enough here in Colorado.

 

When testing diodes, you need to know how your meter works. They're not all the same. You need a loose diode, which will have the cathode end marked with a stripe around the diode. Determine which color lead of your meter results in a low resistance reading when connected to the cathode of the test diode. The cathode of the diode in the compressor clutch coil connector MUST be connected to the dark green wire .

The wire on the left of the clutch coil connector is the dark green wire in my '84, and goes to the high pressure safety cut-out switch, where there are two wires connected to the same terminal. The other wire at this terminal goes to my ECM, pin 21. The third wire, on the other terminal of the safety switch, goes to the low pressure cycling switch.

 

I went back to the manual and checked the wiring schematics and found out where the wires go. Installed a new ran switched, mounted the compressor and condenser, almost done, the diode is connected right, still have the original connector.

 

Update: I just finished installing all the new components, cleaned the condenser, hoses and evaporator, installed green o- rings, filled the compressor and most important, installed a new AC Delco fan switch I found on EBay for around 23 dollars. The original problem was no AC and the fan coming on as soon as put the key in, now the fan did not come on until the temperature hit 195 degrees so I think that is solved, now will take the car to the shop to evacuate and charge the system, the way things look, it seems the AC will work, will post later the resultson't

 

In case anybody is interested, charged the Vette air conditioner today and now I have a good working system so far, drove it and came back home and everything is still ok(for thirty two years it was inoperable) but I felt a small backfire, going to check timing and maybe try 8 degrees.

 

How did the AC system cause the backfire? How do you think the timing caused the backfire if it is at 6 degrees? Are you sure the harmonic balancer is not slipping?

 

I don't think the a/c work has anything to do with any backfire, I had worked on the injectors,timing,pressure regulator etc. I installed a 1985 pump and could not adjust the pressure to at least 13 pounds, going back to check everything again