is there a way to test the water temperature sending unit?

[crocadilen]

Before I buy a new one I just wanted to see if there is a way to test the unit? The car is a Scirocco mk2 16 valve, and the rad fan is not coming on, and the water temperature gauge inside the car is not reading anything either.

[ragnar's vw]

ground sender wire to the block with the ignition on. gauge should go to max hot. then you'll know gauge works. if it does work it's probably a bad sender.

[crocadilen]

Thanks! I just grounded all three of the wires, one at a time and nothing happened. All I know is that one of the three wires has voltage on it, but the gauge never moved. What could be wrong? it has to be this unit because the rad fan won't turn on either, any ideas please?

[crocadilen]

This relay is tied into the fan, and temperature gauge; this may be the problem. Is there a way I can test this relay, to see if this is why I have no readings, and fan operation. thxs

[Sallad]

The temp gauge (one in the dash) and the fan switch (the one that turns on the fan) are two different senders.

Temp gauge is on the side of the head, and the fan switch is on the rad. As for grounding out the sender unit, it only has one wire. You must be trying to jump out the rad fan switch.


Modified by Sallad at 8:09 PM 7-13-2009

[crocadilen]

Thanks, I don't know what to do now, because the stuff is so confusing ugh! Everything that goes wrong with this car is always so freaking complicated to sort out; I mean why could the dial not move for me? Why is the fan not coming on?

[crocadilen]

The unit on the block has been replaced already, and you are probably right I was probably trying to jump out the rad fan switch Well it's not the water temp sender on the block, so what is going on? If I take the instrument panel out, will I be able to see the wire connections, for the water temp gauge? Can I check for voltage or anything to see if that is why I have no reading on the gauge?

[Sallad]

Have they worked before? and now just died, or never worked since you bought it/did a swap?

If they have never worked, I'd double check the wiring. Starting at the fusepanel.

Don't get scared with these cars, they are quite simplistic once you get the "idea" of how the Germans do things. You can do a lot of work yourself on these cars. Hell, I did a complete motor swap and I've never done one before. It wasn't that hard. So I'm sure you can figure out the rad fan and gauge.

Find out what wire is the gauge wire and see if it's even hooked up. Look on the link and trace the wires that don't work.

http://www.a2resource.com/electrical/CE1.html


Modified by Sallad at 8:28 PM 7-13-2009

[Sallad]

So by looking at that, it's wire B07, a yellow/red wire.

So go under the dash, open the fusepanel, find plug B and wire 7. Then shave off a little of the insulation on the wire, so you can see some copper. Then hook a wire to a ground, and touch the copper of wire B07. This should max out your gauge.

If not, you have a break between the cluster and the fusepanel. Or your gauge is no good.

[crocadilen]

Your are a genius... I might have just found the problem (crocodilen goes to check fuse # 15)

[crocadilen]

earlier I was checking all the turn signals, head lights, and I found that the reverse light was not working(#15)
Well after your wiring diagram I noticed that #15 runs the reverse lights too, so I went to check the fuse. Would you believe the fuse is not even in the car so I guess that will be my first step replacing the fuse thanks for the help, and I will update this post tomorrow; unless I find a fuse like that tonight..

[Sallad]

Right on.

[crocadilen]

I found a brand new radiator fan control switch, go figure. I just installed that, tomorrow I will see if that fixed the fan problem. I was looking at the diagram again, and fuse 15 is ok.

Modified by crocadilen at 10:13 PM 7-13-2009


Modified by crocadilen at 10:15 PM 7-13-2009

[crocadilen]

Ok, I found the wire, and grounded it. The gauge still did not move. I don't have any lights in the cluster, so there is other stuff wrong, I didn't think they were related but maybe they are? I am wondering what I should be doing next, any ideas ?


Modified by crocadilen at 10:51 PM 7-13-2009

[crocadilen]

My rad fan switch was bad, so the fan works now. The water temp inside the car is still beat. I noticed today that the red light for the water temperature started flashing right away, just as soon as I turned the car on. It goes on and off, and if you smack the dash the you can see that the whole gauge is loose. Smacking the dash also makes that water temperature light flicker on, and off.

Modified by crocadilen at 8:32 AM 7-14-2009