Advice on TVR Speedo

[AlanP56]

Guys - quick piece of advice please.

My lovely 4.5 Chim - 2000 Reg - suffers from the whizzing speedo problem i.e. every now and then (usually during moderate acceloration) the needle moves over to 180 MPH and stays there. On coming to a stop e.g. at an island, it resets to zero but on moving way the needle (again) whizzes over.

The problem 'comes and goes' and occassionally leads me to having the 'wheel and sensor' cleaned, other times it solves itself.

Any bright ideas please for a more permaneant solution?

Many Thanks

Alan P

[pk500]

sounds like they speed sensor or wiring shorting out

[spitfirestef]

Same problem on my 2000 450. Happened about 18 months ago on a long journey and put a lot of miles on the clock!! I endedup having the actual speedometer unit replaced and no problems since.

[Golflion]

AlanP56 said:

Guys - quick piece of advice please.

My lovely 4.5 Chim - 2000 Reg - suffers from the whizzing speedo problem i.e. every now and then (usually during moderate acceloration) the needle moves over to 180 MPH and stays there. On coming to a stop e.g. at an island, it resets to zero but on moving way the needle (again) whizzes over.

The problem 'comes and goes' and occassionally leads me to having the 'wheel and sensor' cleaned, other times it solves itself.

Any bright ideas please for a more permaneant solution?

Many Thanks

Alan P

Try this link
http://www.speedograph-richfield.com/html/speedome...

[AlanP56]

Thanks Guys

I shall "hotfoot" it to my local garage with the ideas.

Many Thanks

[blitzracing]

I suspect ther is a bit more to this, as I think (??) the speedo is electronic, so if it goes crazy its likelt to be the internal electronics or the signal being fed into it. There is a unit under the dash called a speedometer calibration unit that takes the signal from the sensor on the wheel and converts it for the ecu speed signal, and may well alter it for the speedo as well, although I dont have a circuit diagram to be sure. Ive only had one of these to bits, but the soldering on the main socket on the PCB was very poor leading to a very intermittent connection, that in this case cased the idle to stay high, as it was the ECU speed signal that was intermittent, but Id start looking for the fault here. You have to remove the top of the dash to get at it however.