Need help with starter solenoid wiring

JPC412 · Post by **JPC412** » 23 Feb 2011, 17:29

Car is a 1993 Volvo 850 2.4 GLT 5spd. manual

Was poking around the engine bay, and noticed the small thin greyish white wire that connects along side of the B+ RED wire was heavily corroded and seperated itself from the starter solenoid post. It is just hanging loose in the engine bay. I need help identifying the function of this wire. Keep in mind, the car starts normally and there are no problems with the starter. Just would like to know the purpose of this wire for piece of mind. I find it kind off odd that everything still works despite this break in connection. Anyone know off hand? I was thinking maybe an immobilizer or neutral saftey switch wire???

To recap...
On the starter solenoid itself, there are three wires total:
-A spade connection wire for the ignition switch signal. (GRN)
-On the solenoid post the thick B+ wire. (RED)
-On the solenoid post the thin wire. (GRY/WHT?) - this is the broken wire.

FCPEURO · Post by **FCPEURO** » 23 Feb 2011, 17:40

I bet it is used just to send a signal to the computer or some kind of relay that the starter is getting power. Don't see what else it would be used for.

JPC412 · Post by **JPC412** » 23 Feb 2011, 17:44

Possibly so.

There is no CEL and the starter turns over instantly.

Thanks for the input FCP.

Post by **BEJinFbk** » 23 Feb 2011, 17:46

Does it appear to be stock?
Maybe someone was picking up a constant
12 volts for something aftermarket...

FCPEURO · Post by **FCPEURO** » 23 Feb 2011, 17:47

BEJinFbk wrote:Does it appear to be stock?
Maybe someone was picking up a constant
12 volts for something aftermarket...

Good call. That could be the case, but it would be an odd place to get power from.

JPC412 · Post by **JPC412** » 23 Feb 2011, 17:53

It is definately a factory fitted wire thats supposed to be there. I have verified this by visually checking other 850's at the salvage yard -they all heve the same wiring.

In the pic I provided you can sort of see the wire I am talking about.
The greyish wire goes on before the big B+ RED wire.
Both wires get bolted down on the same post.

Note how the wire is sort of stressed out and bent in this pic. Thats where mine broke.
It leads down to the main engine harness that spans the engine bay.

JPC412 · Post by **JPC412** » 23 Feb 2011, 19:30

I am thinking the wire might be related to the Park/Neutral start switch circuit?

Reasoning that my 850 is a manual shift and functions perfectly.
Somebody will chime in with a definate answer. Thanks in advance guys.

JPC412 · Post by **JPC412** » 23 Feb 2011, 23:01

I found a better picture and labeled it, just to be a little more clear. Refer to my initial post for the pic.
Once again, the little white wire is broken. Anyone know what it powers or where it leads to?

Post by **BEJinFbk** » 24 Feb 2011, 12:55

The closest I got in the wiring diagram world was '94.
I found nuthin'...

JPC412 · Post by **JPC412** » 24 Feb 2011, 16:26

Figured out the mystery wire!

The white lead is the 12V power source for the cooling fan. Took the car for a long drive and let it sit idle for about 10 minutes to get it nice and hot. Then carefully, while minding the fan, I touched the wire to the RED B+ starter wire. The cooling fan relay clicked and the fans turned right on.

Just figured I would post this as a follow up. If your cooling fan isn't working and the relays check out, check the little white wire going to the starter solenoid to see if it is broken like mine was.

I'll just deal with no fans for now, but once it gets a bit warm I might have to rig something up. The space down there is really tight. Too bad my PCV systen is working just fine, I could easily make the repair with the inlet manifold removed.

For those who attempted to help, I appreciate it. Thanks for the replies.