Archived Help Needed!

[KLuzadder]

I need help my manifold heater doesnt work neither does the light in the message center for the manifold heater or the water in fuel light. Also my 91 automatic wont shift to overdrive and the speedometer and odometer do not work. The diagnostics computer says the key switch is not on but the truck starts and runs fine except for in cold weather now and it shifts fine throughout the first three gears.

 

[Alan Reagan]

A relay controls the grid heater. You might try swapping a couple of relays to see if that gets your heater/lights working. Overall (if all fuses are good), you may want to pull the under the hood connectors and see if they are corroded or dirty inside. Also, check the ground connections and make sure they are clean.

 

[Joe G.]

You should post this on the 1st gen forum. That's where the guys who know about your truck hang out. Check all your fuses before doing anything else. With those symptoms I would check to see if the ignition on circuit has a problem. It would be a good idea to fill out your signature and profile so we know about your truck and where you live. Maybe a member who is close by could give you some help in finding the problem.