Heater fan electrics

[MrChips]

Sitting here on a rainy day I remembered that my heater fan stopped working a little while ago and a gentle tap on the underside of the dash got it going again. I've pulled out the electrics under the passenger dash and in doing so, the fan stopped running again, but some general wiggling of wires got it working.
Now I can't get it to fail again so can't locate exactly which part of the loom under the dash is likely to be the issue. Does this look like something related?



Also does anyone have any photos of the main earthing points on a Tuscan?

Cheers

[rxgreentiv]

It is usually the heater ecu/ controller that burns out the pins. The tapping under the dash may be causing a connection temporarily? The ecu is above the footwell on the passenger side (black box about 10x5x4cm) and I used Paul Smith - 07985-355014 who knows them/ tvrs well to recondition mine.

[NWTony]

IIRC and I believe there is a thread on this somewhere, it is usually the connector itself to blame. I seem to recall you can build your own from parts but the issue is having to buy the individual components in multipacks. Can it be wired directly, eliminating the connector altogether?

[paul1962]

The photo above is of the fan drive circuit.
As already mentioned, the connector usually burns out.
The capacitors can also cause problems, this is usually easy to spot as their case with bulge and they may leak.

Edited by paul1962 on Sunday 10th January 13:27

[MrChips]

Thanks all,

Gave the wires to this a wiggle and the fan cut in and out. Taken it apart and cleaned all connections and it now seems solid. Going to mount it slightly better than it was (wedged) so hopefully this should sort it!

Cheers!

[QBee]

Just been out in my Chimaera and, guess what? Yup, heater fan not working.

About two years ago I had the burnt out connector issue (yes, Chimaeras get it too), and I bypassed the burnt out bit and soldered a wire directly to the circuit board thanks to a thread on here. About a year ago it stopped working again and some my TVR guy took the control box and switch out, wired me in a bypass, and sent them off to Paul Smith.

They came back and we reinstalled both, and got the fan working at the second attempt. It's been working fine......and now it isn't. Hence I have no heater.

Any thoughts where I should start with my checks? I think the switch still clicks when I push it (99 Chim, so the alloy on/off rotary speed control), but will check that first.