bureau13

One thing I noticed when verifying that my fan does in fact work, is that I have a hard time keeping the wires connected to the sensor (this is the sensor on the lower driver's side of the radiator). I'm tempted to just bypass the switch and have the fan on always during the summer, although I'd prefer it simply work properly. Anyway, the connections are under a rubber boot, and whenever I pull the boot back, one of the connectors falls off. I'm not sure it's actually connecting at all when I put the boot back on. Looking more closely, the spade on the switch seems very short. It didn't really look broken, but perhaps it is. I didn't think much about this, because my AC isn't working yet and I haven't really had overheating issues, but somewhere I saw a picture of one of these switches, and the spade terminals did NOT look short. So perhaps I need a new switch. Anyone have a pic of theirs with the boot and/or wires off?

If I do get a new one, would it make more sense to get the lower temperature version? Without AC in the picture, I can sit in traffic and the temps definitely get higher than they do while moving, without any sign that the fan is coming on (which may of course be my connector issue).

Ducman82

Sounds like the switch needs to be replaced. On my car the boot just covers the connection. It's not there as a standard plug. Attach wires to the terminals then cover with boot.

FredR

As I am aware that switch is used to trip the a/c in the event the engine is overheating- thus helps protect the engine. Thus if you have no a/c it is academic whether it works or not.

If the connector is duff you can get a 2 pin connector from one of our parts heroes or revamp with some new wiring.

This thing [to my knowledge] has nothing to do with fan operation which is a completely different and complex sub system.

Operation of the a/c system causes both fans to operate irrespective. I presume your model is configured like the S4.

Regards

Fred

bureau13

Actually, that's the way my boot is as well, it's just that the wires inside are very short, so the lack of "grip" on the one terminal makes it difficult, if not impossible, to keep it connected when the boot is put back on.

Any thoughts on going with a lower-temp switch?

Ducman82

On my 81 the AC fan has two ways to be tripped on. The high side temp switch and the radiator switch. Not sure on later cars. I ended up replacing the high side temp switch with a trinary high/low switch with the fan coming on a little earlier pressure wise. The radiator temp switch is still there, but the pressure switch will trip the fan first.

I think the 951 switch is a lower temp......

jpitman2

Get the leads off the switch, crimp the connector tighter, test their grip on the flat pin in the switch. Tighten until it takes a robust pull to remove. Maybe a tiny bit of lube on the boot where the wires go through it so it will slide easily. Then it will stay in place. Test operation by shorting the connectors together.
jp 83 Euro S AT 56k

bureau13

Not sure if we're talking about the same thing...as far as I know, this switch only impacts condenser fan operation. In fact, the way I verified my fan was good was but shorting the two wires together...fan came on, so it's good.

bureau13

The lube on the boot is a good idea, I didn't think of that. I did try to gently crimp the wire-side connector a bit tighter, but I didn't want to completely deform it. Really, the sensor side just seems too short. I have to take another look at it, it must have snapped off or something.