just the other day i tried to turn on my heater and it wasn't working. i turn on the defroster and the vent and neither one worked. i checked the fuse and its fine but it still doesn't work. what could it be?
thanks

____________
1989 d250 2wd diesel single cab long bed.

 

Turn the setting to high, go out under the hod and check voltage at the connector. Or just smack it on the backside while you are ther to check voltage.

 

If you have no fan speeds, it is typically the switch if the fuse is good. Low speed only would be a fan motor going out and high speed only a resistor. But not always. The circut is fairly simple to follow. Start at the motor and work backwards towards the switch and you'll find the problem.

 

I had mine quit about a month ago on me. Double check your fuses. Mine was loose in the fuse panel and was causing a bad connection.

 

well im going to try to fix it all this wknd hopefully so we'll find out soon.

 

i got my heater blower working. all it was was the controls. they went out for some reason so i took one outta my other truck and put it in an it works again. thanks for the help

 

This is usually what will lead up to your blower motor first becoming intermittent and then failing all together.

This will usually start to smell at first and then there may be some smoke.



This was a genuine BUSS fuse.



At this time you also need to put your hand carefully on the bottom of the steering column below the ignition switch and see if it is hot, about the same time the wiring and ignition switch had burned up.

You might notice that when you turn the key to ON or Start that it will stick.



There is too much resistance in the wiring and in all of the connections for the blower motor.



There is a schematic for the blower circuit in here. https://www.dieseltruckresource.com/...d.php?t=158400
Jim