Question for you part time elec people. If i put a tester on my car battery while she is idling should the voltage reading fluctuate. It jumps from 13.2 to 14.5, up down, up down. When engine is off it sits at 12.9.

 

Not looking good. Regulator is probably on its way out.

 

Thanks

grim_reaper. Would that in turn upset the engine management unit

 

As long as it stays within a range of 13-15v when charging ( engine running ) it should be safe.

I would recommend getting it inspected & replaced/rebuilt ASAP.

 

I will do that tomorrow. It varies at idle by one volt or so. Is that enough to inhibit the engine control / management from doing its job properly. I have noticed it will sometimes not go into overdrive. i have an oil leak on a rocker cover gasket. i will get that replaced first as that may have caused the fault in the alternator with oil leaking in to it.