Heat/ No Heat / Heat

[4ways]

hello everyone.

I had no heat from the dash vents for the last week. I have some time off so I wanted to sort it out. On my way back to the house I tried turning it on and it works flawlessly.

I have an X-15 on an international with 192000.

I noticed a few months back there was no heat when I cranked up the defrost one morning. I tried getting into the dash to see if it was a stuck blend door but couldn’t really get to it. I got as far as carefully changing the in dash cabin air filter and later noticed the heat was working again.

Fast forward to a week ago. There was no heat from the heater vents. I tried the heat at least once every morning for 3-4 days there. Yesterday, on my way home, I turned the heat on just to see what would happen. Heat was back on.

Now I was suspecting the thermostat because after warming up, the guage seemed to be pinned at 175 for those few days. Even climbing the hills through Alabama and Georgia it was pinned at 175. But it was on the cooler side outside (maybe 70 degrees out going through the mountains) and I had a very light load (11,000 lbs) so Im not sure if it should have climbed to around 200 like Ive seen it on harder pulls. Now when the heater started working again the temp guage seemed to read a bit higher (maybe 180-185ish) but I was empty and on flat ground so Im not sure how high it should get on those conditions, honestly.

So I guess my question is, is it possible the thermostat is intermittently failing?

I was sure it was a blend door after it worked again after changing the filter but now Im thinking thermostat but the intermittent part has me unsure.

Thanks.

[Rawze]

blend doors on prostar are a common issue as they get older and warp... cheap-o plastic.

[4ways]

Thanks Rawze. I know this thing is gonna go back to no heat when it gets freezing cold. I’ll look into how to get to the blend doors and see if I can make it less likely to stick.

[hhow55]

(11-21-2023 )4ways Wrote:  Thanks Rawze. I know this thing is gonna go back to no heat when it gets freezing cold. I’ll look into how to get to the blend doors and see if I can make it less likely to stick.

May be a bad actuator, if it has one.

[JMBT]

Maybe failing actuator that moves the blend door? short in the wiring to it causing intermittent power or ground loss? Or the more likely culprit, (if anything like a Volvo) the climate control module, or whatever electronic brain crap international uses.

[4ways]

(11-22-2023 )JMBT Wrote:  Maybe failing actuator that moves the blend door? short in the wiring to it causing intermittent power or ground loss? Or the more likely culprit, (if anything like a Volvo) the climate control module, or whatever electronic brain crap international uses.

Did some recon on my 2022 LT625 this morning while changing the disgusting in 4 months inside aire filter and located the 2 actuators. One is under the fuse box under the top of the dash in front of the passenger seat (this one likely controls the recirculate / fresh air blend door). The other is behind the bottom part of the dash thats held on by 4 T-30 bolts. You can only see half of this one the top half is tucked behind the top part of the dashboard.

They both have the same part number on the round green sticker.

   

[Rawze]

I fought with mine a few times.. here is the summary and what I did along the way...
ref: http://rawze.com/forums/showthread.php?t...7#pid38327

[hhow55]

(11-23-2023 )4ways Wrote:  

(11-22-2023 )JMBT Wrote:  Maybe failing actuator that moves the blend door? short in the wiring to it causing intermittent power or ground loss? Or the more likely culprit, (if anything like a Volvo) the climate control module, or whatever electronic brain crap international uses.

Did some recon on my 2022 LT625 this morning while changing the disgusting in 4 months inside aire filter and located the 2 actuators. One is under the fuse box under the top of the dash in front of the passenger seat (this one likely controls the recirculate / fresh air blend door). The other is behind the bottom part of the dash thats held on by 4 T-30 bolts. You can only see half of this one the top half is tucked behind the top part of the dashboard.

They both have the same part number on the round green sticker.

Truckac.com has that part $20.70

[kjjohnson1980]

I ended up replacing the thermostat, and that seemed to fix the problem for me. It's possible that your thermostat is intermittently failing, especially if you noticed the temperature gauge behaving strangely. It's not a super difficult DIY job if you're up for it.