2nd Gen Non-Engine/Transmission Wipers, heater fan fluctuate

[AMink]

I'm new to the site. Holy cow! Too much info? I think not. Anyway, when my truck is idling ('97 2500 Ext. cab LB 4x4), the lights, heater fan, and wiper speed fluctuate. It's not a big deal, but is kind of annoying. I'm hoping that it isn't leading to a bigger electrical problem, but it has been happening for years with no apparent further problems. Any suggestions?

 

[pwknapp]

If it's just when you first start it, it's probably the pre-heater just drawing power till all is warmed up.

 

[AMink]

It was doing it even after I had been driving for a while. I pulled up and watched the lights on the garage door. They almost "flicker" at idle, but were fine with a little pedal. I suppose as long as they're on, I'm ahead of the game! Thanks for the idea. Man, you could spend a lifetime on this site!

 

[Un-Hemi]

Hello! Welcome to the site. Yes, the amount of information on here can be overwhelming... kinda like being a sugar addict in a candy factory.



You didn't mention anything about the batteries in your truck; if they are old and/or weak and the demands on the alternator are high, then the voltage on the system will fluctuate more than if the batteries are new and/or of good quality. The battery connections may require cleaning. Of course, the alternator may be marginal, but it takes some diagnostic work with an analyser at the battery shop to determine that.



Could be that your idle speed is a tad low also.



Cheers!



Tom