Voltage Regulation

[PMalin]

I have noticed that sometimes my lights will brighten slightly, and if the blower fan is running, sometimes it speeds up for a brief moment. Has anybody else been noticing similiar results? Maybe this is happening if the battery charging circuit is kicking in and out and a subsequent voltage increase is happening and then goes away, when it quits charging. It doesnt seem to be a big issue, just one of those minor things I noticed.

 

[Gizmo 007]

Mine does it when you first start the truck, then for cycles for 30 seconds to a minute. Seems a little odd in this heat, but it's the intake heat grid turning on and off. I tested this with my multimeter. Unplug them and see if it still happens.



If I remember right, your alternator also has a regulator built in. It could be going south. Get a digital voltage gauge that plugs into your cigarette lighter. That ought to give you some hint.



Just my 2 cents.

 

[Great White]

Sometimes the A/C kicks in. The flicker is the magnetic clutch pulling in. Rich

 

[Extreme1]

Actually, I think the voltage regulation is done by the PCM. (I recall reading that in the FSM) In the winter, after the heaters cycle, the voltage will be higher than when restarted warm or in the summer.