self leveling susension air system question

had to replace the compressor on my 94 RMW for the self leveling suspension but couldn't find one for any 94 gm car all I could find for 94 was the air dryer, so ordered a compressor for a 95 RMW and just got it today, while installing it found that the relay on the new compressor had four terminals, while the relay and plug on the original compressor has five terminals and was wondering if anyone here would know if there is a difference between the 95-96 air suspension system verses the 94 system or is it just a modernization of the compressors function?

A lot of times the 5th pin is the N/C contact that is typically not used in the 4 pin variation.

If you can post a picture, that would help confirm.

here are pics of the terminals on the relay and the diagram on the side, though I did notice that terminal 87 is doubled

Interesting - I'm guessing the harness only has 4 wires? if so, then no functional difference other than the extra 87 terminal instead of 87a.

that's the old relay and the old compressor was wired for all 5 of the relays terminals


the new compressor is only wired for the four terminals on the new relay that came with it

Any pictures of the new relay?

I did some more looking on both old and new compressor and on the car side harness, the extra wire on the old relay goes to a terminal on the main plug, but on the car side there is no terminal there so that part of the relay was never used

Simple enough

yeah once I had the time to actually think, between cleaning out the garage so my mom can get her van in next to my Buick, trying to figure out whats going wrong with my 3d printer,, still tryin got get things organized in the house from our move between De Pere and Stevens Point, and getting ready for two big craft shows coming up.

So, figuring out what you are missing is easy.... 85 and 86 operate the magnet, meaning one of these is the "trigger" wire (either by positive trigger or negative) and the other wire would either be ground (if positive triggered) or hot positive (if negatively triggered)..... #30 is your hot, fat positive feed that runs the switched item (compressor) (8-12 ga wire)...
87A (middle connection) is hot while magnet is at rest (not energized) and 87 (top) is the fat switched wire that is hooked to the compressor.......
This relay is a standard Bosch (style) 5 wire relay that is interchangeable with the fuel pump relay, the AC compressor relay and others throughout the car....They are a very common automotive relay used in many applications where switching 30-plus amps remotely is necessary.....
It's my guess that the missing spade connector is the one in the center (87A)