Anybody had the same problem

[Rich912]

When driving along all the temps and pressures are steady until you turn on the fans for a bit of cool air and then the temps and pressure constantly rise and fall quickly causing the water temp display to flap up and down and if at idle the drop in oil pressure causes the dash warning to go off.

On further inspection it also happens momentarily when the windows hit the bottom stops. It looks like whenever you apply a significant electrical load on another circuit it takes some power away from the dash pod as the ligths on the pod also dim very slightly.

I've checked that the alternator is working and as far as i can tell everything is earthed ok. If anyone else suffers from this or if anyone has any ideas as to what it could be please let me know, thanks. Rich

[nelly1]

Could be a loose earth or a hairline crack in the 100A fuse (on the back of the starter motor).

[pete]

It's worth checking the 24 pin connector between the dash and ECU harness, which is tucked up above your knees under the driver's side dash. Make sure all the connections are good and clean. Also do the same with the main plug to the PCB at the back of the dash pod; a dodgy earth can cause all sorts of odd dash readings.

Pete

[Arapo]

Is that happening with the AirCon on, or just with the fans on and AirCon off? If you have the AirCon on, the drop in oil pressure is normal, as the idle revs would fall by around 100 or so.

[ochten]

dubble check the main earth cable (including the insidepressing of the cable in the connector) between the engineblock and the tube. That could be your problem! First remove the airfilterhousing and altenator to see it clearly)

[Rich912]

Thanks guys, i will check those points and see if i have any luck

[ochten]

Please let us know what it was (If you find the reason)

[Rich912]

In typical TVR fashion the problem has gone away, however this was a consistent fault for over four months. I am doing alot of other work on it at the moment and this other work including dash pod removal may have disturbed something. I had checked all the points that were mentioned above and all seemed fine, i also disconnected and reconnected the 80 Amp fuse in the passenger foot well although this also seemed fine.

There are still a few electrical systems to be connected back up and if any of these introduce the fault again i'll know where to look and will post on here accordingly.

Thanks again for all the advice, Rich