Hi, I have a 1988 Ford Cargo 0813. The speedo on the tacho was working okay then it began to work on and off, very erratically. The needle sometimes doesn't move at all then it will jump up to say 40 mph then fall back to 0. When I switch the truck off I can hear something electrical inside the tacho working the needle will jump up to say 15mph and go back to zero. I have now disconnected the tacho. Any help is appreciated.

Malcolm, October 2010

Thanks for replying I know I am a long time in replyng I hope to try that

MD, January 2011

may have a broken wire ....to check it you would need to break the seal and do a continuity check on the wiring ..if the wiring is at fault it's easier just to rewire it with 4 core from tacho to sender ,you then need to prebook it in to a tacho centre for a complete recalibration ,as i can't see anyone just resealing it

norb, November 2010