meat27

Hey yall, I just picked up a 92 D350. It's my first cummins and I love it already. D350 reg cab dually, 5.9L, getrag 5spd, 3.54 diff, 2wd.

I drove the truck home 100 miles no problem. It ran and drove fine (steering will be tighter when I rebuild the shaft coupler).

I have some problems inside the truck that I'll mention to see if yall know about any common issues (since I'm new to these trucks) before I start digging into this stuff from scratch.

On the a/c heater control, if I push in any button other than "off," the lights in the above Cummins display will come on (parking brake, wait to start, water in fuel, etc) If i turn the heater control "off", the lights go back off. When turned on, I can hear some slight rustling of leaves from I guess the blower, but hardly any air comes out.

The power windows won't move because they aren't getting enough voltage, they are getting a tad, but not enough to move. I can jumper wire the window motor direct from battery and it moves fine.

Also the speedo/odometer isn't working. All I've verified is that the wires to the vss are in place.

All under-dash fuses are good.

Onemoparnut

Make sure the vss has a good connection to the wires. I would bet you have a ground issue under the dash causing both the window problems and the problem with the idiot lights also.

meat27

Okay, found something. The window and a/c control aren't getting sufficient voltage from the ignition switch. I jumpered 12v to their circuit in the fuse box and now both are working properly. I don't have the proper tool to open the ignition switch, so I might start looking for a replacement. Or, I might just rig it somehow.

As for the speedometer, I guess next I'll verify proper connection onto the VSS. Is it common for the VSS to go bad?

My smile is getting bigger and bigger about this truck

MARF75

welcome to my world!
Both those circuits are fed from the same wire from the ign. switch. Pink w/blak tracer feeds switch and then black with orange tracer feeds those 2 circuits in the fuse block from the switch, I bet they are melted some where(column,fuse block)Mine are at the connector at the ign. switch and the block. Get an FSM it well help tremendously!! I just wish I had enough electrical know how to address all my issues.
Good Luck

Jim Lane

Check here for your heater circuit.

https://www.dieseltruckresource.com/...d.php?t=158400

This is what will happen when the blower motor draws too much current through the ignition switch, you will also find burned wires under the ignition switch, as well as the switch.



Jim