92 or 93 4x4 truck speedometer possessed!!!

[GseaQ]

Hey all,

This is BIZARRE! The speedo is accurate for about 1/2 hour when the truck is first driven for the day or after a multi hour cooldown. AFTER about a 1/2 hour the speedometer will start to read higher than actual - 60km/h will read 90, 70 will read 110, 90 will read 145 and 100 km/h has the needle pinned against the trip odometer reset shaft.

This happens every day. It is not related to bumps. Yesterday the speedometer was accurate when stopping at a stop sign, but was wonky 10 seconds later when I started driving again. It seems like some electrical component (resister maybe?) is heating up and faulting. Any ideas anyone?

Oh yeah, the truck is a 5-speed manual and is completely stock with over 200,000 kms on it. This problem has been intermittent for a couple of years, but is now every day.

TiA,GseaQ

[MaximA32]

The gauge isn't mechanical soit can't be the cable just fraying. Sounds like there's a short in the dash somewhere.

[GseaQ]

Thanks Kenny,

I had hoped to avoid taking the dash apart, but I guess I'll have to start tracing electrical stuff. I think I'll start at the transfer case end, though!

GseaQ

[MaximA32]

Sounds like a good plan.