Blower motor shuts off when I turn my lights on 98 dodge ram 1500 5.2L
Asked by Casey Aug 25, 2016 at 07:49 PM about the 1998 Dodge RAM 1500 Laramie SLT Quad Cab 4WD
Question type: Maintenance & Repair
I am a diesel mechanic and have a good amount of experience but, this
one has me stumed. The blower motor works fine in all speeds so that
checks off the motor itself and the resistor as a problem. What happens is
when the parking/dash lights are turned on ( one click on the light switch )
The blower motor completely stops. First Idea was a weak ground. I tested
every ground that had even a remote connection to this circuit. They all
passed with in the noise. So I tracked down the common power line to the
blower motor controller and the light switch ( and orange keyed power
source) I put my test leads on it to see if I could find any weird behavior.
With the lights off every thing seemed golden bouncing between .4 and .8
volts and with in the noise in resistance everywhere I could test it. So I
assume there is no whack shorts. I then turned the lights on with my test
lead in the controller's side of the wire and the wire jumped 10v. That does
not seem right to me. Any ideas ?
10 Answers
From the web...."The blower speed switch and the lights that illuminate the heater controls share a common ground. You have a bad ground with that circuit. So when your lights are off, your blower is finding a ground, "backwards" through all of your lights. When you turn the dash lights on, the ground goes away." I hope this helps.
Any clue where the ground is I believe It is g201 and I thought I checked it.
No, sorry you will have to examine all the associated wiring. I would start at the heater control lights and see where they ground to.
Any luck finding the ground? I have exact same issue with 2001 Dodge Ram 2500 5.9l v-8.
Corey u ever get the answer I have that same problem with my 2001 dodge 2500.
DodgemanCometh answered 6 years ago
Drivers side under the battery there is a Gang ground. Pull the battery and remove all the corrosion from the ground wires should fix the feed back issue. And lights and blower motor.
robmclatchie answered 3 years ago
I have the same issue (1999RAM 2500 8.0 L) Light switch on, blower motor cuts out. Blower works fine in all settings with headlight switch off. The 1999 RAM 2500 doesn't have a gang ground under the Batt, there are 2 black wires attached to a stud mounted on the inner fender between the Batt and windshield solvent filler neck. I replaced the connectors on the wires and relocated the stud to a non rusty part of the fender, still no joy. Also noticed that the windshield wipers are inop as well, looks like all (Lights/Blower/wiprers) share the same common g100 ground. Any ideas?
staycool72 answered 3 years ago
I just had this issue with my 2001 Ram 2500 5.9L V8 and it was an issue with the trailer wiring, pulled the relay under the hood for the trailer to pull out the blower relay and the blower shut off, so I disconnected each wire one at a time and the very first one I pulled out was drawing amps to it causing the problem, put the trailer relay back in and hooked the wire back up, now all is good. Hope this helps
staycool72 answered 2 years ago
The issue is with the gang of ground wires on the drivers side fender below the battery, I had the same issue and that was the whole problem
