Lights dimming back and forth
 

I can notice it with the dome light on while going down the road, but mainly as i am easing through the trails while heading to the camp, my lights will dim then go back and dim and go back to normal, it is almost like something is cycling, such as the compressor or maybe using the power mirrors. Any idea what may be causing this?? I could troubleshoot for days and never find this problem. the gauge is reading fine.

Kip

mine does that when I 1st start it up and will do it till it "warms" a bit, not to running temp, just when the temp gauge starts to move is when it will quit...


another thing that I have noticed that when the AC comp. is on it will do it every so often....and when you have your defroster on the ac comp. cycles on and off...

my volt gauge also stays good, and I have had the electrical system checked just to be sure...

hope that helps...

Grid heaters still cycling after its warm? bad relay?

I read that the grid heaters will cycle when the air temp is at a certain temp and vehicle speed is below so many mph. I experienced it driving old logging roads in Northern Wisconsin late last month -- my truck was at normal temps from the highway trip up, but several miles of slow travel through the woods had the heaters cycling in the cold. I want to say it is anything less than 17 mph, but I don't remember the temperature.

I also notice it a bit with the defrosters on, but I don't use them too much anyway.

Grid heater is supposed to work if manifold temp is 59 or below until you hit about 10 mph or so then computer turns them off. Try disconnecting them.

A/C compressor will cycle with the defroster on, also defroster/floor blend.

Mine also does it when vent/floor blend is selected.


phox

I think that mine will cycle at every speed. I know it especially does it while going through the woods. but i think even going down the interstate. will find out for sure tomorrow night heading out of texas. how do you disconnect the grid heater?? Won't it affect my startup if i disconnect it??

Kip

The power lines are easy to disconnect, just a couple of lugs and nuts. Should be able to tell pretty quick and reinstall if no change. If it's not real cold you should not have any trouble getting it started. Just make sure you don't short out the lines off the heater to anything, they carry up to 90amps and would make a great welder!!

You don't have to remove the lugs to disable the grids.
Just remove the small trigger wires going to the two relays almost under the drivers side battery. They just slip on over a post.

I have pulled the relays once. Right in the Power Distribution Block by the Battery.

check the signal wire connections for the relay! mine were loose and my headlights would flicker constantly even when driving down the road! Almost bought a new pcm beacuse i thought it was the voltage regulator!

my 01 does the same thing. i was told by 2 dealers and dodge.com that it is part of the alternator relay. they said it does it so that the batteries do not over charge. it should only do it under extreme conditions ie cold weather, veh sits at ildle for long periods or low rpm levels. you should also notice a small clicking sound comming from the engine compartment when the lights dim as well as the volts drop from 14 to 12-13.5 untill the alt clicks back on.