When I turn on any air heat/air or just blowing fan at idle gages like oil will drop to zero then jump back up/ Sometimes it will even die and need restarting. Engine is at 500rpm at idle. What could cause this. Any relays or something simple maybe or is it a short in wire? Please help give me a place to start, thanks
It sounds like the fairly high current draw of the blower motor during start up is causing the problem which may be due to a bad connection in the power bus for those areas or a bad ground to those things. To see if it is a grounding problem you could try adding a temporary ground lead from the battery to the dash area and see if the trouble clears. If it doesn’t then try to find the common power source to those areas having trouble and look for a bad power connection to them. It may be at the fuse panel under the hood.
I would start with a check of the voltage at the battery with the engine running. If it is less than 13.5 (should be about 14), then your charging system is not working correctly. If so this is usually because of a failing alternator.
If the battery voltage is good, then you have a poor power or ground connection somewhere between the battery and the interior fuse box.
I would also check to make sure you have a good ground to the instrument panel