93 940 turbo wagon

[Ed]

You guys are great. New problem, just started.

My Tac will become erratic at low speeds or idle. It will very from 0 to 2000 rpm or more. When is get to highway speeds it reads normal. I suspect and electrical problem as the condition changes with lights on or off. Blower on or off, etc. Earlier I had ask for help on a chirp sound in the AM radio. I'm thinking there may be a connection, perhaps in the alternator or regulator?

Suggestions please

Ed

 

[James Sweet]

You guys are great. New problem, just started.

My Tac will become erratic at low speeds or idle. It will very from 0 to 2000 rpm or more. When is get to highway speeds it reads normal. I suspect and electrical problem as the condition changes with lights on or off. Blower on or off, etc. Earlier I had ask for help on a chirp sound in the AM radio. I'm thinking there may be a connection, perhaps in the alternator or regulator?

Suggestions please

Ed

This sounds like a grounding problem somewhere. How's the strap between the cylinder head and firewall? There's another ground wire on the alternator, and of course the negative battery cable.