Yellow WIre, Terminal 50, Starter, and A/C Relay Issue
 

Ok Everyone, I am pulling my hair out trying to figure what the hell is going on with my 930.

I am trying to diagnose why the yellow wire going to the starter is HOT when the ignition is just "on" and not when cranking.

I have found that the yellow wire (terminal 50) is also connected to an air conditioning relay in the smugglers box. On this Relay the Yellow wire is connected to the internal coil of the relay PIN 85. On the other side of the relay's internal coil there is a black wire connected to PIN 86.

What has got me really stumped is this black wire is also a HOT wire.

So I figure what is happening is 12volts positive is coming into the relay via the black wire, through the internal coil and out on the yellow wire which is inturn connected to the starter.

I found this diagram here on Pelican and although it is a little blurry it shows that infact this relay (J22) is connected to a black wire coming from fuse S11 and the yellow wire connected to the starter.

If I disconnect the yellow wire from the relay in the smugglers box, the 12volts goes away in the "on" position and works properly when the key to turned to the "start" position.

http://forums.pelicanparts.com/uploa...1320372767.jpg

Why in the world would this relay be wired with two 12v+ hot wires???????


Anyone?

I made some notes to the above diagram to help explain what I am trying to figure out.

http://forums.pelicanparts.com/uploa...1320374168.jpg

I think this issue is a major contributor as to why so many of us are having starting and a/c problems.

I thought about it for a while and all I can come up with is.............

As electricity follows the path of least resistance, the yellow wire acts as a ground for the relay in the smugglers box when it is not energized by the ignition switch.

Since the yellow wire terminates at a coil (the starter solenoid) it is ultimately (other than some windings) a direct path to ground.

When you turn the key to the start position, the yellow wire is energized and the current flows directly to the starter solenoid.

There must be a diode in the relay to prevent this current from reaching the black wire through the relay in the smugglers box causing a short.

If this is how this is supposed to work, I am proposing disconnecting the yellow wire in the smugglers box and running a proper trigger to ground connection.

Paul491's car had a bad A/C relay that would cause his car to start cranking while the engine was running. The person that originally troubleshot it missed it entirely, his car ultimately needed a new wiring harness because of it and other issues relating to it.

( I think it is done like that to "turn off" the A/C while cranking. )

Wow that really sucks losing a wiring harness! Well, at least he didn't lose the car up in flames. Very scary either way!

I've searched and found tons of threads on starter problems, parasitic draws, and no start conditions.

I wonder how many of these problems can be attributed to this circuit.

As a better solution I think I am going to remove the yellow wire from the relay in the smugglers box. Add a seccond relay that will have pin 30 to ground and pin 87a to the smugglers box relay (replacing the yellow wire).

This will supply a ground to the relays coil and activate the air conditioning.

On the seccond (new) relay I will wire pin 85 to ground and connect the original yellow wire to pin 86.

That way, when the ignition switch is turned to the "crank" position, It energises the new relay and removes the ground to the relay in the smugglers box, turning off the a/c.

It probably won't hurt to add a fuse to the black wire going to the a/c relay in the smugglers box as well.

I'll post some pictures to help explain what is going on.

Although I can't read the schematic I think the relay you are referring to is the load reduction relay on the AC.

One side of the relay coil goes to hot and the other to the starter terminal.

• When the ignition switch is not in the start position there is essentially zero volts on the solenoid terminal and the relay coil is energized by the current flowing from the battery through the realay and through the starter. The current to close the relay (and limited by the relay coil resistance) is minuscule compared to what it takes to pull in the solenoid.
• When the ignition is in the start position there is 12 volts on the starter solenoid terminal. With 12 volts on both sides of the AC load reduction relay there is no potential across it to make charge flow and the relay turns off disabling the AC and whatever else when the car is cranking.

EDIT: nevermind. I see you figured it out in post #3

Thanks for the replies guys.

I hope this helps anyone having problems with starting or this circuit.

Here is a picture of the Relay in the Smugglers Box. The yellow wire in the pic is the one that is also connected to the starter solenoid.

The black wire is coming from the fuse block and is hot at all times.

Oh and this is on my '84 930.