Heater not working

[justinwregier]

I am new to the forum and new to my 86 M1009 (purchased 1/25/09)

Currently my heater does not function at all. The previous owner mentioned replacing the blower motor but needing to replace the fan switch in the control panel. I tried the original fan switch while it was in the dash with no success so I then removed the dash and replaced the fan switch with a new one... still no heat. The fan does not come on at any setting.

The previous owner does have a 12v line into the cab for something but the motor turns over easy on starts and all the lights work... just struggling with my M1009 in this Ohio winter with out a heater.

Any help, leads, solutions, comments towards HEAT in my CUCV is welcome.

Justin

 

[NDT]

Did you check the fuse??? Are you getting 12 V to the motor? If so, replace the motor, they are avail at any auto parts.

 

[justinwregier]

I will put fuse/12v connected on my checklist, thank you.

I am in TM 9-2320-289-34 for the wiring harness and the path the cables are running to make sure all the connections are in order. I hope it is something as simple as a fuse or hooking up the 12v.

 

[ida34]

There is a resister inside the heater housing that provides low and med heat settings. It basically drops the voltage. You may have a problem with it. Most of the time when they go bad the heater works on high only. Basically the power comes from the switch and goes to the resister. Then from the resister it goes to a condenser on the cucv. From the condenser it then goes to the motor. The condenser is not used on civy trucks and is for radio noise suppression. You might also consider checking to make sure the condensor is not bad. You can remove it and just wire the blower motor feed directly to the line like on civy trucks. If it works fine then the condensor is bad. When the blower motor switch is on high the motor gets 12 volts. In the med and low setting the voltage should go down progressively. Do some chasing around with the voltmeter and you are sure to find the problem.

 

[justinwregier]

NDT/ida34
thanks for the leads... I will pursue these as I am off to the shed to try again

 

[CARNAC]

I had similar issues in the past. My heater finally started coming around after I had a new thermostat put in. The resistor is another item that was replaced so not sure which it was. You can get new heater parts pretty inexpensively through LMC truck. I tried the used route once and didn't get anywhere until I finally replaced things with new parts.

Now that my truck is wrecked, I'm now working the same issues again with my parts trucks.

 

[justinwregier]

While having the dash off to replace the fan switch there was a bulb (looks like a migrated dash light for the fuel/speedometer) that had a loose wire. This loose wire when contacting metal would light up everything... also NDT there was a bad 20amp fuse so maybe this bad bulb caused a short? anyway the electrical is not stock on this M1009, its not terrible but certainly not as issued in 1986. go figure the worst thing for me is electrical... anyway heat works now.

Thanks so much for the feedback, makes me want to put wifi in the shed so I dont have to leave to research an issue.

Had my M1009 for about 34 hours now and I am really excited to drive it in the morning!