Coolant temp gauge pegged...
 

My electrical gremlins were the result of a very weak battery (8 volts).

However, the one issue that has not resolved itself is the coolant temperature gauge. It pegs full scale as soon as I turn the key on the cold engine (warning light is not illuminated).

I have the (Chilton) manual, the electrical section is all pretty cryptic, It looks like the sensor is a variable resistor mounted on the right side of the cylinder head, going to the DCU, translated to a K-bus signal, sent to the tachometer pod.

With the warning light not lit, tells me it's not the sensor, and almost equally unlikely to be the DCU, but in the tach-head assembly where the digital K-bus signal is translated back to "analog".

The manual makes changing the tachometer head look like child's play, is it?

Does anyone know of a good source of used parts?

Thanks for everyone who posted with their suggestions. /sac

I fixed the problem, and it didn't cost a dime.