Hey guys, im looking at getting a g body car agn, having sold my fbo new
caprice ppv w/ the 6.0, and i seen an el co for sale near;
Posted as not having working tach or speedometer. Is that a resistor gone bad in dash board? I remember looking this up when it happened to my 3rd gen. But also no heat. Does that the entire dash needs to come out to fix all that?
The speedometer is run off cable, the tachometer I BELIEVE is electronic. Two different issues here, either will require you to remove the dash pod (cluster) to fix.
As far as the no heat, that could be VARIOUS things. Let's say you go to take a look, run the engine for a while and see if the heater hoses get hot, both in and out, if they are, try to get the fan to blow heat in different settings, windshield, floor, vent ect, if no heat is extracted, then you may have a gate stuck in the heat exchange box. if this is the case, that may require entire dash removal, NOT FUN.
If you start it up and run it, and there is only one heater hose hot, then you have a blocked heater core, if NO HEAT on either hose, then the engine may have no thermostat, bad head gasket ect ect.
NOW Check to see if the upper radiator hose gets hard as the engine is running (SHOULDNT BE INSTANT, should build pressure as the engine heats up slowly) and stays hard as the engine and hose heat up, this indicates its building up adequate pressure AND SHOULD be supplying heat to the heater hoses and has a thermostat. If you start the engine and the radiator hose gets hard almost instantaneously, another indication of a head gasket issue.
These are just some pointers and it's really difficult to diagnose anything not in person and typing on a blog, hope this helps!