Tvr tuscan mk1 speedometer reading intermittent. Please help

[richard exley]

My speedometer behaves erratically... Sometimes you can start the car, go for a drive and the speedometer behaves smoothly... Other times it'll bounce around a bit... A few times it has dropped out completely... I replaced the transducer 24 months ago and everything was working I'd get the odd flutter but other than that it was fine when it was replaced.

Now if you're doing 40mph it'll fluctuate anywhere between 20mph and 50mph and occasionally it'll sweep all the way to 190mph and then drop out to 0... Then spring back to life again...

If I really drive hard and hit over a ton, it'll often drop out completely...

I did have a load of dry solder joints on the dash PCB a few months ago, which were causing all sorts of issues, I re soldered them all, and everything is working... Just the bloody speedo causing me trouble intermittently... It'll work well for a couple days sometimes... Then misbehave for weeks...

Any ideas?

Thanks

[ColdoRS]

Does the digital readout mirror the analogue? If so, I expect it's the transducer again.

If not, check the plastic on the pod isn't fouling the needle. Also check the needle has been fitted correctly or hasn't moved - does it read higher or lower at 0mph?

[richard exley]

Yeah both the digital and the analog are misbehaving...
Looks like it'll be another bloody sensor... Going to have a quick check of the wiring tomorrow before I bite the bullet and adjust the air gap again, in case it's too close and causing interference.
Cheers for the help

[richard exley]

Sits exactly where it's supposed to at 0

[nawarne]

richard exley said:

Yeah both the digital and the analog are misbehaving...
Looks like it'll be another bloody sensor... Going to have a quick check of the wiring tomorrow before I bite the bullet and adjust the air gap again, in case it's too close and causing interference.
Cheers for the help

Richard, the fact that both digital and analogue outputs are behaving in the same way, indicates to me that it is in the sensor/transducer.

Think folks have mentioned to check the connector in the boot. I'd also add that a silicone spray onto the worm drive for the speedo needle might help?

Nick