Alternator or belt problem??

[Dave 52804]

I've got a question for you guys. Right after I start up my M1028 I hear a slight "click", a small squealing noise, and the voltage gage needle drops down a little. At night the headlights dim a bit. Then after a few seconds the squealing stops, the needle climbs up and the lights brighten back up. The truck runs fine and neither alternator light comes on. I've only had the truck a short time. So what gives? Thanks in advance for the help/info!

 

[PaulbusMax]

I know nothing about your vehicle, but interestingly, that is precisely what my two Dodge Cummins diesels do (less the squeal). In my case it is the intake heater grids cycling, drawing huge current. Depending how cool it is outside they may cycle like that for a minute or so.

 

[mistaken1]

That is the glow plug relay actuating when the engine is still cold. That is normal.

The load of the glow plugs and resistor causes the alternator belts to squeal and the lights to dim. Might try tightening up the belts a bit to see if the squeal goes away (don't over tighten).

The gauge will still register the voltage drop as the glow plugs cycle on and off.

 

[PaulbusMax]

Hey, i was sort of right! Good to know things are working correctly on your end.

 

[Dave 52804]

Thanks for the prompt replies fellas!! This site and it's members are great. It has been a bit cooler here lately. Probably just things warming up a bit.

 

[1986Blazerk5]

That is the glow plug relay actuating when the engine is still cold. That is normal.

The load of the glow plugs and resistor causes the alternator belts to squeal and the lights to dim. Might try tightening up the belts a bit to see if the squeal goes away (don't over tighten).

The gauge will still register the voltage drop as the glow plugs cycle on and off.

That makes sense to me as well, I does sound like a loose belt tighten the belt and the squiling should stop, if it dosent I would replace the belt, I have had good luck with Goodyear Gaterbacks a little more $$$$ but well worth it