Redwing's disconnected wires

[FastWoman]

In response to Redwing's private email, I'm starting this thread for her.  She has 5 disconnected wires and is trying to figure out what they do, where they're supposed to go, etc.

 

First are "2 blue wires coming out of wrapped bundle" here:

 

 

The one on the left (from center of image to top center) is not blue.  Rather, it appears to be black with a blue tracer (stripe) on it.  (Very big difference!)  That may be the wire that goes from the "start" position of the starter switch to the middle of the drop resistor for the ignition coil.  This isn't absolutely necessary for your engine to run, but it energizes the coil a bit more when you're cranking the engine, making it start more easily.  I have no idea about the wire on the right.

Edited June 22, 2015 by FastWoman

[FastWoman]

Next, "from red (sensor???), connected wire.  near coil"  Here:

 

 

The red "sensor" is a noise suppression capacitor with some red paint on it.  Neither end is connected.  I don't see it diagrammed in the ignition circuit, and you can probably remove the part.  It was probably installed to suppress electrical noise to a previous owner's stereo system.  By the way, there's a clip that holds the coil wire (that goes to the distributor).  It wants to be inserted onto the metal tab about an inch to the left of it.  You also have the wiring harness (wrapped in black electrical tape) running very close to the coil wire.  That's probably not a good idea.  It would be good to have a bit more distance between them.

[FastWoman]

Next, "black wire disconnected, other end attached to outside of compressor.  Maybe ground?"  Here:

 

 

I assume you mean the black wire on the right.  If one end is attached to the body of the compressor, then it's indeed a ground.  Black would be the correct color code for ground also -- although black is also used for other things, like almost every wire in the EFI wiring harness!  Anyway, this black wire, which is a ground, should probably be connected to the body ground point on the left side of the photo.

Edited June 22, 2015 by FastWoman

[FastWoman]

Finally, "disconnected white wire from/through firewall"  Here:

 

This wire isn't OEM.  It was added by one of the previous owners, and I would have no idea what it is.  You should be able to find it on the other side of the firewall and see where it runs.  In all likelihood, you can take a pair of wire clippers and remove as much of the wire as you are able.  I suspect it serves no more purpose. I see the end wrapped in electrical tape, so it might be live (+12 V).  Be careful when you snip it that you don't short it to ground.  Perhaps tape the exposed end when you're done, just to be safe.  The two black wires emerging from the same hole are also non-OEM.

[FastWoman]

Hope that helps!

[FastWoman]

Jai, that solid blue wire with the bullet connector MIGHT run from the (-) terminal of your coil to the tachometer.  However, as I said before, your ECU is being triggered, and the blue wire at the coil is common to both the ECU and tachometer.  That's how it's reflected in the '76 schematic diagram too.  It's possible you've got some modification going on.  But blue is the correct color code for the trigger wire.  If you know how to use a multimeter, you should test for continuity of the blue wires to the #1 pin of the ECU and to the tachometer (I think the terminal labeled "S").  If you don't know how to use a meter, you should find someone who does.  The worst thing you can do is to hook up wires where you think they might go (without confirming what they are).  That's a recipe for having stuff blow up.

[EuroDat]

I posted this already, but something went wrong, so Ill try it again.

 

Looking at your wiring, its very similar to mine. The blue wire with the bullet connector goes to your A/C compressors magnetic clutch.

 

The capacitor with red overspray has two wires coming out of it. One connects to a black wire coming out of the body harness directly behind the coil. If you look in the wiring diagrams, its the last ground wire before the Check Connector plug (Mine is anyway). The other end goes to the distributor body. In the photos below you can follow them carefully through the jumble of wires around the coil.

Its a noise supression capacitor for the radio. I wouldn't worry about it too much. Like Sarah already mentioned, its not on any of the wiring diagrams Ive seen and the car will run without it. It is an original piece of equipment.

 

The wire coming out of the firewall is not original. Don't know what the last owner wnated to do with it????

 

 

Chas

[Redwing]

Euro Dat

Thank you for your observations. I will take my novice eyes and see if that works for me.

[Redwing]

EuroDat

Will the blue wire with the bullet connector that goes to the A/C compressors magnetic clutch, when reconnected maybe start the AC?

Thank you

[EuroDat]

It would be one of the conditions require for it to run. I think there would be more things to investigate before trying to start the airco. The fact that the bullet connector is disconnected strongly indicates it wasn't functioning when the PO removed it. More than likly no gas in the system or damaged compressor.....

Some simple things you can check is for starters. Is the system complete.

-Are all the A/C hose/piping connected and no visible damage.

-Are the vacuum lines still in place, vacuum tank on the other side of the engine bay, fast idle actuator on top of the inlet manifold etc.

The FSM has some good diagrams in the 1977 edition. See section AC-36 and AC-37 for the vacuum hose en electrical harness diagrams. There is also a good diagnostic system for trouble shooting in the FSM starting at page AC-40.

The FSM has a good description on how the system works and what all the individual parts do. It would be advisable to read up on this before going any further. Background knolledge would also help if you when to an A/C service centre.

If it all looks complete you could check if it has pressure. The compressor has to valves with caps where the hoses go to the compressor. They are use to service and test. You can remove a cap and check for pressure or get a specialist to check with his gauges. I doubt it will have any because it been sitting for a long time. Compressor seals tend to dry out and start leaking over longs periods of not being used.

The next question would be what refrigerant does it have now, has it been converted?

This system was designed for a refrigerant called R12 which worked at a lower pressure than the modern day equivalents like R134a. R12 was banned for enviromental reasons and the system will work on the modern refrigerants, but not as effective.

It you do decide to get it working, don't expect to much from these systems. Its not a modern day system. No climate control or window defrosting, just cool air. Basic creature comforts....

[FastWoman]

^^^ Everything that Chas said!  If you were to look at my Saturn, you would find the same thing:  The wire to the clutch on my AC compressor is disconnected.  Why?  It's because my compressor went bad, and I couldn't seem to get other people to stop trying to turn the AC on.  Unplugging it was a simple solution.

 

Not knowing anything more about your AC than it being disconnected and sitting, I'd suspect it will cost a pretty penny to bring it back.  I'd say you first see whether it has pressure in it by poking the stem of a Schrader valve (like on your tires, except on the lines near your compressor).  If you've got freon, that's good news.  Next question is whether your compressor pumps the freon.  You would try reconnecting that wire -- or better, just sending +12V to the compressor clutch.  Does the compressor run quietly?  Can you feel the lines changing temperature?  If so, then good.  If you've got cold air, all the better.  But I bet you won't.  if you have some freon and the compressor pumps at all, then you might take the system to a qualified auto AC technician.  He'll have to figure out what's already in the system, what it needs, etc.  It will probably need evacuating and recharging.  You can find R12, BTW.  It's a bit expensive, but it's available on sources such as ebay.  I remember it being maybe $30 a pound, and you will need a couple of pounds.

 

But chances are your system doesn't hold pressure (all the freon gone) because of a bad seal (compressor needs rebuilding), or even more likely the compressor has bit the dust and won't pump.  That would be an expensive thing to fix/replace.

 

I've retrofitted a couple of R12 AC systems with R138a.  I don't think I would do another one.  Results were fair at best, and the R12 compressors don't hold up very well under the higher pressures.  (My failed Saturn AC is a 138a retrofit, for instance.)

[Redwing]

Thank you two again. The AC system has been changed to R31a. The mechanic in Jacksonville tried twice to recharge the system with freon, which bled out overnight. I was never told if it started immediately after freon in. He decided to abandon it then. Interesting about the systems not doing the change effectively, but actually not surprising since there is about 35-40 years of progress. Fully understand about all the hoses etc disintegrating, again the years alone will do that. I would be thrilled for "basic creature comforts" with no complaints. Heat affects me physically, always has since childhood.

Ebay has a complete upgrade AC system for my car, and others, for $895 I believe. Alot for me right now, but I wish.

I will read up on it all in the FSM. I think since you said 77 edition that it covers 76 ' s too.