I have an issue with the heater in my 93 ctd . When I turn on anything but the off button on my heater , the wait to start and the water in fuel light on the dash comes on . Also the fan will not work . Wondering if you guys think it might be the switch itself or could it be a loose ground somewhere ? I had the dash all apart today and couldn't find anything visibly wrong . It seems as though the previous owner tried to take the dash apart before and got frustrated because most of the tabs holding the dash and componentry together are broken off . I'm thinking it may be related but not sure . I'm also going to look around and try to find a complete dash to replace the one in my truck . Anyone change out the entire dash before ? Is it a major pain or is it something I could tackle in a day or two ?

 

First thing to check when electrical gremlins show up is the ground from the battery to the core support behind the head light.


As for removing the e tire dash, you have to pull the windshield to get at some of the screws.

Look here.
https://www.dieseltruckresource.com/...n-t255283.html

 

The common point to those circuits is in the round plug that is on the rear of the dash cover right above the heater..
it could be something as simple as a wire being shorted when you move the hot/cold slider,or a corroded or loose connector.. before getting too carried away, pull the dash face off, and check this conector!
Mine was dirty and causing my oil pressure gauge to read funny.. a little dielectric grease solved it!
Always try the easy things first with electrical issues..

 

I checked that plug . It wasn't the problem . I also found a replacement dash . I'll be installing on the weekend if I can find someone to re and re the windshield . Does anyone know the basic procedure for testing the heater control switch itself ?

 

So I found a dash in good shape just wondering what's a fair price ? Going to get it tomorrow . Thanks

 

Take the plastic lower cover off the steering column and have a look at the electrical connector for the ignition switch. It's pretty common for the blower circuit to overheat and melt there. Two causes are the tilt steering eventually loosening up the terminal on the connector, and a worn blower motor drawing too much current and overheating the connection and the ignition switch.

When you get the wiring fixed, measure the current draw with the blower running on high. If it's over 18 amps, replace the blower motor.

 

When my blower started getting intermittent the first clue was the smoke coming from the steering column and the bottom cover got burning hot and melted.

It eventually took out the ignition switch so my first repair was to replace the ignition switch and then I installed a relay to switch all of the IGN circuits on the fuse panel and to take all of the electrical load out of the column.

The path from the battery to the blower motor has a lot of weak links and several of mine were melted.

There are pictures of behind the dash in my article.
https://www.dieseltruckresource.com/...d.php?t=158400

Here is a schematic of the blower circuit .



And this one shows the addition of my relays.





Jim

 

thank-you .

 

Trying to find where the feed from the ignition switch to the fuse box for heater power but my wiring diagram is pretty vague . Anyone have the dodge fsm with that shows (sh 5) or the ignition switch page ?

 

So far I've changed the ignition switch , the resistor for the heater , the fan motor and the heater switch itself . Nothing has worked . But if I put a jumper from the red wire on the bottom of the ignition switch to the black wire with the red stripe I get the blower to work fine . I'm a little confused as to how it's wired . Is there another relay somewhere I've missed ? I do appreciate any help . thanks

 

Look here.

http://dens-site.net/Dodge_CTD/1991.5-Wiring_Diagrams/