Overheating - radiator problem ? (PB Engine in T3)

[Stefvan]

are you using the gauge sender from the original T3 engine or from the PB?

The temperature sender is black, a VW part 251919501A which I think is the original one from the PB. I thought it was interchangeable with 251919501D which is the one for T3's.

I checked the radiator fan, it works on both speeds when I short the connections, However it doesn't seem to come on, although after a short run the engine doesn't seem to be overheating now for some reason. I measured the cylinder block temperature at 90 degrees C and the radiator at 79 degrees C, while warmed up and idling. Not sure whats going on, I'm confused. The left side of the radiator is now the same temperature as the right.

I will call it a day and go on another run when I have time and see what happens. I can order a new thermoswitch, and if necessary a new temperature sender.
Thanks all again for your advice and help.

Stefvan

[lloydy]

i have found the non T3 senders are a bit hit and miss.. on my tdi conversion the sender from the donor car never read right, needle was always high on the gauge. I fitted a T3 sender and all was spot on.