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Waterloo

Just thought I would post this information regarding our ProStar HVAC systems and the TWO potential FIRE hazards in your dash. I have a 2008 model, built in 2007. Sadly, few of the dealers know about these TSBs, you have to know what to ask, and have a service manager that will take the time to look. The TSBs are there, we found them under wiring, or electrical harness. My particular truck was not covered by these TSBs, but I sure had the problems! So, even if you do not fall under these two TSBs, just do these fixes, it may just save your life, your ride and your income.

On Edit: If you don't want to read the entire post, skip directly to the last paragraph.

One TSB relates to the HVAC blower motor wiring harness, the other is for the Linear Power Module mounted on the blower motor. This is your cab blower motor for the front HVAC, not the sleeper HVAC system.

The issue, the blower motor draws quite a bit of amperage. The old fix was to pull the 30 amp breaker and replace with a standard automotive 30 amp fuse. The breaker would overheat and fail due to the high amp draw and heat. When this happens your blower motor will not work until everything cools down, or you reset your breaker.

The automotive fuses suffer the same overheat fate but are cheaper than breakers, they normally have to be replaced several times a year in my truck as they do fail. And they fail without blowing. The dealers fix is to install a new blower motor. The blower will work until the fuse or breaker heats back up... Sweet little racket the dealers have going...

In time, these fuses will eventually melt and a breaker will just fail. The fuse block will also melt, due to the high amps/heat, as will your wiring connections/harness. My fuse block is melted where this fuse/breaker sits as were my harness connectors. This is the fire hazard and the reason the TSB was issued. Problem is, it took several calls to the dealer before I got my guy to dig for it, and he found it, as again, my truck does not fall under this TSB. I do not have the TSB number, but I have the fix.

International has a jumper, or as it says on my receipt, Cable ASM -HVAC Jumper W/Resistor. The part number is 3865234C92. There is a resistor soldered in line on the power side, it sucks up the heat/amp draw that causes everything to melt, and or the potential to catch FIRE.

The cost for this jumper/resistor at my dealer was $34.83, list is $46.44. You can also find this part on the internet for a bit less. Myself, I would just purchase this at the dealer, that way you know you are getting the correct part. Just my .02

You will need to pull the lower kick panel, locate the harness that runs along the floorboard at the firewall. I do not recall if you had to pull the HVAC box apart to get to the blower motor LPM connector. I don't think you do. This cable plugs in between the HVAC harness and the blower motor LPM harness. If your connections are melted, like mine were, clean up as best you can. I used a small pick and screwdriver to square it all away. It was almost to the point of not being usable, I got lucky, the plug was a mess but fixable. To add, the dealer does not sell replacement plug pigtails, you are on your own there.

This new harness w/resistor is suppose to solve the overheating issue and eliminates the potential fire hazard. FIRE hazard, did you hear that? FIRE. Purchase and install this part ASAP even if you are not on the TSB list. Remember, my truck was not on the list either but was affected. I would say that the older your wiring gets, the greater potential for fire. Don't mess around, just do this. So far, I have had no issues with my blower motor or HVAC system since doing this fix, it seems to have solved the problem. And I was eating blower motors, I have installed three this year alone, replaced under warranty... This third blower motor is working as it should since the harness fix was installed, I am now confident this solved my problems. .

The other FIRE hazard in your dash is the Linear Power Module. That is found attached to your HVAC blower motor. You will need to remove the kick panel and front lower cover to get to the air box that holds the blower motor and LPM. It is held in with half a dozen torx head screws. There are two at the floorboard. There are also two, one on each side of the air box that you have to dig for to get to. They are located at 9 and 3 o'clock on either side of the blower/air box. The rest of the screws are at the top and visible, I believe there are three more, just below the fuse block.

Anyway, dig the blower motor out, the Linear Power Module is the White, 1/4 circle thing with the spikes on it. It is held in place with two torx head screws. The part number is 3562102-C1 and has a TSB for potential fire hazard, it overheats just as the blower motor harness does and is a potential FIRE HAZARD according to Navistar.

So, I bought a new one at the dealer, FIRE, I ain't screwing around. It was roughly $250 and I ate it. Meanwhile, just a few months prior, I had bought a Linear Power Module from these guys for $65. http://www.truckerac.com/blower-resistor...21021.html

It is the identical part that I purchased at the dealer. Same barcode, same numbers, same manufacturer, same stampings, same everything. I could not tell the difference between the two so I left it in and will keep the $250 one as a spare. I also called Trucker AC to find out the date of manufacture, he told me the one I had just purchased a month or two ago were just delivered direct from the manufacturer, they were the latest OEM model. I was confident with the answer as these parts were visually identical, but had different stampings than an older LPM I had laying around. So I think I am OK, but that is up to you which part you purchase.

There you have it folks! I hope this helps someone, and I would do these repairs ASAP, especially if you are having blower motor issues. Check your fuse block under the cover of your dash. The fuse is right up front center. If you see charing on the block, you are playing with FIRE. Also, if you have to periodically reset that HVAC Blower Breaker going down the road, you have this problem. Or, if you run the blower motor on high and it starts acting up, you have this problem, FIX IT, purchase that Jumper Cable. If your truck catches fire it will go up in flames in seconds. I have seen a few burn to the ground, and when they go, they go. By time you get to your fire extinguisher it will be to late.