Mackpro

I remember the parts guys had a hard time finding the harness in the parts break down but lucky for us the tag was still on it and the part number was readable.

Here is a link to the Mack Reman center catalog and it can be used it see what’s compatible, https://www.bergeystruckcenters.com/efs/wp/domains/www.bergeystruckcenters.com/wp-content/uploads/2021/09/REMACK-Product-Technical-Brochure_compressed.pdf

There is coolant around the cup so if you don’t drain the coolant before you remove the cup then it will fill up with coolant.

https://static.nhtsa.gov/odi/tsbs/2017/SB-10090649-6903.pdf

I have seen the engine brake plunger/pistons unscrew themselves causing this issue. Also with that high of miles I’d really look for broken valve springs and for the intake and exhaust valves to start wearing up into the valve seats. Especially check this if the engine has been deleted.

I bought lots and lots of the Factory manuals over the years when I was at the dealership. Most were $8-$15 a piece. I have this one in print so I knew what it looked like and just did a quick search and it turned up. The Mack E-Media site is free but I think it’s mostly Service Bulletins now, it used to be full of manuals. Also the Mack Body Builder website has lots of free maintenance info that’s way easier to navigate than the dealership website. In related info RH Sheppard and TRW both have all their steering gear manuals free online. Eaton Fuller has all their transmission manuals online as well . Bendix also has lots of free manuals on ABS/brakes.

Here is a link to the factory manual for several different HVAC models, make sure you use the correct model . https://s6dc2dc82dd3d959c.jimcontent.com/download/version/1549531542/module/8252074015/name/Air Conditioning System Service Manual. Includes US 07 Mack Chassis%2C GU (Granite Series)%2C CHU AND CXU (Pinnacle Series)%2C MRU AND LEU (Terra Pro Series).pdf

The 460 XT was only for the original ETECH series. The CCRS series was like the ASET AC series with a 460P with 487 HP and a 460E with 460 HP, both were same torque at 1660 . The XT files are still showing up in the Mainframe as unchanged from 1999 on the dealership side. We saw very very few of the CCRS 460p trucks as they only made the CCRS for a couple of years before the ASET came out

If it’s locked solid it’s for sure bad . But as the bulletin said , if you put 12 volt and ground the appropriate pins then the fan should slowly disengage after 10 minutes of engine run time at around 1000 rpm. The colder outside the longer it takes to disengage.

https://pdf4pro.com/cdn/service-bulletin-mckenzie-tank-lines-a3dd0.pdf

That style fan never totally freewheels like a air fan. It should always have some resistance. However if it is locked solid and if the only way to spin the fan is by slipping the pulley on the belt , then the fan clutch is definitely bad. If you can still turn the fan without slipping the fan belt then it’s possible other issues causing the fan to stay engaged. I’ll see if I can attach a bulletin later on troubleshooting. There are two part numbers one for the ASET AI engine and one for the AC engine. They both look the exact same and will bolt up but won’t work correctly if the right part number is used. Also a bad engine harness, coolant in engine ECM , bad AC high pressure switch and over charged AC system can cause fan to never disengage .

What’s the exact model and last 6 of the VIN

The easiest way would be to ask the local dealership to do a horsepower request and see if corporate Mack will turn on the XT program for the new truck. If they will it’s Usually around $300 for the download and a couple hours labor to do it . There are ways around this but it requires dealership access and someone who knows how to trick the Mack mainframe into thinking your installing a new engine ecm on the XT truck . All the old guys who did this stuff where I used to work are gone or retired. I don’t know if the can even program a grey engine ecm any more .

Yes that CV shows it , relay/timer part number is23851995 , no where in stock . Harness is 25187825 and it to no stock anywhere.

I looked up a CV713 with that VIN but it didn’t show it having heated windshield. But there are 7 different CV trucks that have the last of the VIN 001007. CV513,CV533, CV712, CV713,CV500SG CV700GK and another with just only a VIN number

After looking this morning the only wiring diagrams I can find are for 2007 and up MP engine equipped trucks starting with the CXP-CTP trucks and all the way to the newest trucks, looks to be a simple circuit with a 20 amp fuse feeding a dash switch and also a 4 prong relay , turn on switch and this activates the relay sending 12 to the windshield. You could get this in the standard 2 piece or one piece windshield. As far as the relay goes , I don’t know it it’s just a standard plain relay or one like the the heated mirrors and has a timer in it

I have never seen one in real life. Only in the option sections of wiring diagrams. I believe you can still order a new truck with it .

I think I have a wiring diagram at work for the heated windshield on the granite. Hopefully I’ll remember to look tomorrow

We did up graded the “Fleet” shifter to the “Performance” or as Mack called it the “Premium “ shifter in all the used trucks we sold at the dealership. Best I remember the shift key pad was around $500 then a couple hours labor max . Installing the key pad is easy but the harness connector is very tricky to figure out . I remember breaking at least one . The dealership then has to have Mack turn on the transmission ECM software download . Then do the download and then turn on the parameter . There are 2 different settings. One is when you push the “P” performance button it will stay in performance mode till you hit the “P” again. The other setting is after hitting the “P” button, it will go in performance mode till it feels it’s no longer needed the back to normal shift mode.

The AI engine and the CCRS engine use the same part number EUP’s so it’s entirely possible. Engine brake type would be a concern I would think . There is a good bulletin out there that has all the part numbers and info for engine type and engine brake type used

2-7 code on a Aset engine is the oil temp sensor. It a 2 prong sensor next to the oil pressure sensor which is behind the rear most oil filter . This sensor is usually damaged when replacing the starter.

The override might actually work after all , I just read the bulletin I attached and it said there is a over ride switch for the electric viscous fan, . There are two different harness connections for the 2 types of ECM controlled fan clutches. There are 3 settings for the fan clutches on the ASET’s. “Smart Fan “ which is the electric viscous, “ On/Off” is the air fan setting, then there is the “None” which is a regular viscous fan. If you select the “On/Off “ setting then only the 2 wire connection at the rear of the engine harness will work, it would connect to the fan clutch solinoid for a air fan . If you choose the Smart Fan setting then only the connection at the electric viscous fan clutch will work. Also choosing the On/Off setting you are able to set engagement and disengagement temps and run times . The fan clutch is controlled by the engine Ecm but the override settings are controlled by the vechicle ECM ( VECU).

Looks like it’s just 1 degree .

There is as no option for fan override on the electric viscous fan for the Aset engines that I ever saw. The option was available for the air fan though. I have seen guys use a dash switch wired in line with the green high pressure AC switch up by the radiator. Cutting the power to the AC switch makes the engine ECM think there is high AC pressure and turns the fan on .

https://pdf4pro.com/amp/cdn/service-bulletin-mckenzie-tank-lines-685fa.pdf This explains operation and troubleshooting of fan clutch. The colder the weather the longer it takes to disengage after cold start .