So right against the firewall is a box that's missing. I don't know what its called, so I can't look it up in the service manual.
This is the end of the alternator plug off the wiring harness. Someone spliced a wire before, but I don't know which connection on the alternator it goes to. I have two spades to choose from. I assume this should have had a plug on it. Need to use electrical contact cleaner on those and get things back to snuff.
These two connectors go back to a sensor. One of them was connected to the A/C compressor. The other was left hanging, but you can see that the plug is actually still connected, with the wire cut. Where would this have gone?
The only wires I can imagine actually on the AC compressor would be for the clutch.
I don't have my 82 book handy, but an additional wire to the alternator might be for a tachometer. I rekon the others (in the plug) are for excitation and output.
I'm sure some of the gurus will have the correct info.
Have a nice day.
'91 Jetta ECOdiesel TD - clean & complete (less motor/tranny) for sale
The red wire in picture #2 (with the taped on bluish green wire) goes to the broken off connector on the right in picture #3.
It has to do with the control system to your A/C and goes to either the pressure switch on the A/C Freon line in front of the strut tower or the air temperature switch behind the driver's side louvers below the grille -- can't remember which.
The left hand connector (red wire) in picture #3 would have the A/C compressor plugged into it.
If you're looking for a tach wire, it will be black, at least that's the way on my '82. It's on the small bundle of pink wires going to the switches on the IP.
On that alternator plug, the two red wires are B+, go to the battery and fusebox etc. The little blue one, F, feeds the alternator's field with +12v; there is no W connection for a tachometer on that alternator.
Thanks for all the input. I'll get things wired back the way they should have been now. Probably remove the green extension wire and redo it with a red wire, soldered and then heat shrink tubing over it and of course a new female spade inserted into the plastic plug.
I believe the spliced wire goes to the AC compressor clutch.
Powers it up, unless the thermoswitch say the engine is too hot.
Some alternators have the "W" terminal for the upshift light.
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
So I'm trying to get the AC working and need to hook up the clutch. As I understand, the clutch should be powered from the green spliced wire in picture two. Power should come from there, go through a red wire to a thermostatic cutoff, back out the cutoff and to the AC clutch.
When I test for power at the green wire, I don't get anything. I tried with the car on, cooling lever on AC, and blower on. My Bentley doesn't give the AC wiring for the 83 rabbit. It does it give it for the other cars in the manual, so I'm not sure where to start probing. I checked the fuse panel and the only fuse that mentions AC is the fan one, which is good.
There is also a black wire, not in any of the photos. Its in the same bundle as the fuel relay line for the injector pump. It doesn't appear to have voltage either. Where does that go? My alternator has a W terminal and I could hook it there, but there seems to be some disagreement about its use.
There are frequently a series of relays to ensure that the compressor runs safely.
One for low pressure,
One for high pressure,
One turns on the radiator fan (maybe two for high/low)
Generally, if the system is empty of refrigerant, the clutch will not engage.
A tach wire is usually light blue.
A black wire in the same bundle with the fuel cutoff wire may be a oil or water sensor line.
Some of my AC equipped cars have plunger-switches at the accelerator lever limits. They may be in separate bundles.
Have a nice day.
'91 Jetta ECOdiesel TD - clean & complete (less motor/tranny) for sale
The green'ish wire (really red a little below that, due to a splice) didn't have power, because there was no refrigerant in the system causing the pressure switch to remain open. Once I put a can in, the pressure switch closed and the AC clutch was able to work.
Still don't know where the black spade connector goes.
MK2 cars had an A/C cut that tied into the coolant sensor on the front of the head. I think the wire that is cut could be part of that. IIRC it cut the a/c and powers the rad fan when temps were too high for a/c but before normal fan operation...could be off on how it works, but it is in there and cuts the a/c feed to the clutch.
I do not see any "black" spade connector pictured. The only black connector is your alt. plug and you know what that is.
