ollie32

Hi there,

I have a 2003 3500 diesel and I am having problems with my interior fan cycling while driving. First it was an issue when I had the A/C on full blast about a year ago. It got worse on all settings and now it does it on heat,vent,a/c doesn't matter what setting its on.
From time to time the big fan will kick on in the engine, the engine isn't over heating though.
I am wondering where to start? Wondering if there is a temp sensor in the system or bad wire, not really to sure where to start.

Any help would be great, THANKS

Greg

Spooler

I am not real clear on what the problem is. Is it the fan on the engine or the blower motor inside the cab?

SuperGewl

Need more info on your truck, what modes you have ect????

jkitterman

The engine fan will kick on and off with the AC and at certain speeds. I notice mine with the AC on and when starting from a stop up to about 20 mph. I have a 2003 with a 6 speed.

ollie32

Its the blower inside the cab that is cycling, ON/OFF ON/OFF. Not sure what is controling this?
My truck is a 2003 3500, stock.

ollie32

I'm leaning towards a Blower Motor Resistor, any suggestions would be appriciated.

Thanks

Greg

caper11

So i'm assuming that the blower is on than turning off, i'd start with checking the ground.

ollie32

I have just been out at my truck with a multimeter checking the voltage.

Here's the deal and I am puzzled because I am not entirely sure how the system works with that resistor in there. The motor will run for a while after sitting and cooling down, then it will shut off. It has approx 12 volts while running without the resistor installed at full power. It will shut off and there is still 12 volts at the connector when it is turned off. I am beginning to think its the Motor overheating and shutting itself off. The voltage doesn't change and there are no other connections tied into the motor.
Puzzled????????????????/

Spooler

Now that I have the full scoup the issue is going to be a burnt wire/connector at the steering colmn near the ignition switch or a bad ignition switch. I have helped several fix this issue on their 03' trucks. Take a look and tell us what you find.

ollie32

Thanks for your suggestion, I will take a look this weekend. I'll also have another dodge close by, good chinese blue print. I can start swaping parts to try and find out whats happening.
Thanks for your help, I'll keep you posted.

ollie32

Hey Guys,

Good news on the western front, I managed to pin point my problem last night while driving. I could control my fan by changing the tilt on my steering wheel, off/on. Today I got out my many torx bits and tool the steering column apart. All I can say is what a stupid way they have assembled the ignition switch. Turns out a contact was pretty worn away, it's been arching in there, nice fire hazard.
Took my bike down to the dealership, picked up a new unit for 30 bucks and I was on my way to the races. So far so good, problem solved for good I hope.

Thanks for you help

Cheers

Spooler

Glad to be of service......That's what we are all here for.....knowledge.