02' F350 7.3L >whenever I turn to headlight switch to the auto lamp position when the truck is running it seems to be shorting out. Not blowing a fuse but sounds like what would be a solinoid under the dash to the right of the steering wheel. this just stated to happen. Truck has been out of service for a few months and I just started using it again. Starts good...
Any suggestions.

 

It's not shorting out. If it were, you'd have smoke or blown fuses.

Sounds like the autolamp relay is chattering. You'll need to dig into the circuit to see what's going on.

Steve

 

See if you can find what's making the noise under the dash.

 

I meant chattering...that's the sound all right. I'll check it out and get back.
thanks

 

Well, I tried to duplicate the same problem, it seemed to solve itself. Maybe its the calm before the storm....

 

Dirt and corrosion never seem to give up. Now that you are using it, it may go away unless you let it sit for awhile again.

 

I hope this is the case. I just get done spending $700 big ones for an instrucment cluster because the door ajar light wouldn't go off. It seems the dealer must do this job because of the odometer has to be set by them. I tried all the other ways to fix the ajar light but nothing worked until the cluster was replaced. It wasn't just the ajar light it was also the interior dome light wouldn't go off and the remote lock didn't work either. So, I'm just praying that it's just a little snaffu and it won't reaccure.

 

The newer trucks have a communication network, almost like a small computer LAN network at a small business. The instrument cluster is in the middle of it.

In the old days, they would have all the wiring coming from the domelights, door locks, seat belt switches, door switches, etc. going throughout the vehicle tying together all the circuits they controlled, usually through a GEM module with timer functions inside it.

Now they have modules everywhere. They will have a module where all the wiring for the door locks and door switches and other body features go. They still have the engine computer, also the abs computer, and now they have a computer in the instrument cluster. All of these different modules and computers communicate with each other over this network in the truck. The instrument cluster is especially important, since it's used as a info center for the driver. So many of the functions that are going on in the truck, are monitored through the network, by the cluster. This eliminates a lot of wires. But of course you have to have special equipment to communicate on the network, and troubleshoot the system. That's where the dealer comes in. I believe I read that something has to be done to a new cluster so the rest of the network will recognize it.