Dead fan - completely confused

[sjmtlewy]

Decided to take a look at the rad fan thermoswitch, as its not something i've investigated before and the van sometimes runs a little hot in traffic. The fan used to come on when the needle got to 2/3rds ish and go off again fairly shortly. I had wondered whether it was a 2-speed with a broken slow setting.

So... Having pulled off the grill, it has a thermoswitch with 3 wires coming out of it (so 2 speed fan, right?). Shorting two of the connections caused the fan to spin fairly loudly. Couldnt get anything else to happen with any other combination of shorting it out. Then tried the original combination once more, but after a short spark trying to short it, nothing. Now nothing spins at all. Bugger.

I've got an old-style fuse box. All fuses are intact and conducting correctly. Checking the voltage at the thermoswitch reads 8V - which doesnt sound right to me. Doesn't increase much with turning the engine on. Might be crud on the terminals - ill check, but it isnt causing any new problems. Reading the Bentley wiring diagrams has left me confused however. Its a '83 1.9DG, the nearest thing in the book is an '83 Digijet - What the blithering heck is a digijet? its def not fuel injected. But that shows two thermo switches and a relay, i've got one switch and an old relay box without any fan-relay that i'm aware of.

So what is actually going on here? Has my radiator been replaced for the wrong one at some point, would that matter? Is there a relay somewhere? Is 8v at the switch right? and what's broken?

[sjmtlewy]

Scratch the 8v, its actually reading 11.5 on one pin and 3.5 on the other two...

[jrt]

Hello, i also have a two speed fan. The relay for my 83 A/S is behind the fuses, there should be 2 relays, the one on the left is the coolant level warning and the one on the right for the radiator fan. I had a load of mither with mine last year, maybe this will be of some help- maybe not!

https://club8090.co.uk/forum/viewtopic.p ... 53&start=0" onclick="window.open(this.href);return false;
David.

[sjmtlewy]

Thanks - I saw your thread before. Given that we both have '83 vans with electrics that don't match the diagram, maybe the diagrams are wrong?

Found the relay myself, I can hear it clicking and have tried swapping it for one of the other ones of the same type. I've now managed to flatten the battery, so have had to take a break. Tbh I'm wondering whether that might have been half the problem - I do so much faffing around on the drive, the battery is always nearly flat. Just creating problems for myself...

[Hacksawbob]

I am not to familiar with the early wiring though digijet is the fuel injected variety, but most of the wiring like the rad fan is similar. But if your radiator temperature sensor/switch has 3 pins then you have the later variety.
looks like this http://www.brickwerks.co.uk/shop?page=s ... ory_id=120" onclick="window.open(this.href);return false;

Not like this
http://www.brickwerks.co.uk/shop?page=s ... ory_id=120" onclick="window.open(this.href);return false;

on page 97.66 of Bentley red blue wire is the high speed fan side, red black is the low speed. The centre is red white and comes from the fuse, so this is switched on the positive side. A good place to start is check the earth points above the fuse box with the crowns of earths.

[sjmtlewy]

Fixed!

Turned out to be a knackered earth which explains why it was so intermittent - the connector was split and knocking around by the crown. Now re-crimped (along with half a dozen others - good job I bought all those nice copper connectors) and works perfectly! I swear i've never heard it on full-speed before, it must have been like this for ages

But I definitely have a 2 speed fan and a single 3-pin thermoswitch, despite it being an '83. Seems the bentley just doesnt have diagrams for early non-injection WBX engines.

[bigherb]

But I definitely have a 2 speed fan and a single 3-pin thermoswitch, despite it being an '83. Seems the bentley just doesnt have diagrams for early non-injection WBX engines.

They do, but they are for USA spec vans which have differences from euro spec vans.

[DavidPallister]

Mine's an 83 1.9DG, it too has a 2 speed fan, think my Haynes Book Of Lies covers both single and 2 speed fans

Dave

[sjmtlewy]

Yup - the wiring is as pictured for the later vans with a single 3-wire thermoswitch and 3-wire, 2 speed fan. The only difference is inside, where the fuse is 16A in slot 7 with a no24 relay screwed to the wall behind and above the fuse box, where none but the most adventurous will find it.