ardakota

Ok have ran 3 full days truck is pulling better and seems to be using less fuel. Seems like it has done what it was supposed to do.

the ac engines fall on their face under 1400 rpm

I just put this on my 04. Ran one day so far seems to run better then with that bad $1300 tube. Fuel use I do not know yet as have only ran one day only thing i get is a 4-9 code when it idles at longer periods which it did that already. So far worth the money.

Finally got it figured out after Mackpro helped me and I found out the high pressure ac switch had a fuse. the cover on the firewall fuse box doesnt have anything showing what fuses are what. I did a little searching and there was no fuse in it. This all started when it was taken to mack to fix the wire going to the vgt controller on the turbo. We picked it up they fixed that but told us they didnt know why the fan wouldnt shut off and sent us on our way.

thanks a bunch I dont know why i didnt think to check the power to that switch I have torn the wire harness part way apart and just happened to think i never checked power at the switch bingo there it was no power. I hooked fused power to in and what do you know the fan works right. Thanks a bunch.

I figured it out somehow it lost power to the high pressure switch.

Been looking all over for the ac wiring diagram for the ac unit on my 04 mack ch with the bergstrom unit can anyone tell me what supplies the power to the High pressure switch.

Would anyone have a diagram of what wires go where to the plugs on the ecm so I Know what wires to test without tearing the whole wire harness apart?

Have you used one before. My flow sender just went out the temp one still is good and they want $1300 for a new one at mack.

Thanks thats what I thought. looking at the ecu log it looks like no events were saved to the ecu but the vecu had some programming in 2013 but who knows where that was.

thanks I believe i read your post so I went out and checked my pressure was like 220lbs I have even put a new switch on it.

has anyone used the resistor that the post says and has it worked?

I have an 04 mack with the aset 460 engine and the behr fan clutch. The fan is brand new It turns off anytime the engine speeds over 1800 which i believe is what its supposed to do. It stays engaged most of the time only pulsing slow and fast and sometimes it will go off for a few seconds then come right back on kinda pulsing. I hooked up the truck to the computer and in vcads the 3 intake sensors were reading +/- 5 degrees of each other at around 110 degrees fan was still on. I could not turn the ac off in the perimeters because i havent a clue on what the password is it asks for. The high pressure switch is new as well and is closed even checked the pressure in the ac system its normal as well. The wires you couldnt read the numbers if you wanted to I dont know who was the brains who thought to put all their wiring the same exact color. Does anyone have the diagram showing where the wires going from the ac switch and fan ar located in the plug on the ecu or any ideas on what else i can do to figure this out. Oh the pulsing makes sense as when you check the soelinoid ground wire it pulses as well. One more thing can anyone help with the password? Thanks

my 04 will do that when the fuel filters start to get stopped up. We also had problems with the turbo actuator not working right is it throwing any codes? How high is your exhaust temp. Also can check for leaks in your intake boots.

I dont know if the rear is the same as the front but the front i replaced with the new type seal on an e7 and mack has you install it a little bit farther in to ride on a new surface on your crank and the little plastic ring is only to be remove from seal when your putting it in its to keep the seal from deforming. There might be a bulletin on the rear main seal I dont know there was for the front.

Yeah it was a full remark engine long block

I have had an intake valve problem when the cam was going out in the previous engine and kept breaking that post that holds the rocker and it always thumped back through the breather bUT I'm like you guys I think it's got to be valve train related. Maybe it's time mack look at their motor it shouldn't be doing this with so few miles.

terminals clean and actually ran a ground in addition to the one thats factory still getting hot on high the fan is new switch is new the only thing in this ac system that hasnt been changed is the thermostat and the resistor. Im at a loss on what to do next.

yes it has a jake it almost sounds as if its not turning off but coming out of the woods in a hard pull your not using it when it does it.

It sounds like an exhaust valve is sticking it doesnt smoke just a thump thump thump sound out the exhaust along with a miss only happens after stopping from a hard pull it will still miss if you keep on going but stop it and let it go to idle then you hear the thump thump

Anyone?

I have an 04 mack ch model and the wiring to the heater fan switch gets hot and burns the switch out in a short period of time it only really gets real hot when you run it on high and the next notch lower it just gets a little warm. Has anyone got a fix for this. Thanks Dave

We have a 2001 mack ch 460 that we put a remack engine in ran great for the first couple thousand miles now when you put it under a hard pull it will begin to miss and when you stop from said hard pull and just let it idle you get a miss and a thump thump out the exhaust then a minute later it will clear itself up. I have never had a mack do that on me so this is new to me. Thanks Dave

we ran ch models for several years as dump trucks mack air rides were always great but you always had to dump the airbags which always made me feel more comfortable because it got your load a little lower and it was real stable . I myself would not want the change but there was an entire suspension setup for sale in the classifieds here in the forum.

i dont know if it works on the 96 but the 2000 model we have you turn your cruise control off and with the key on and a malfunction light on press and hold the set button on the cruise control when the light goes out let off it the light will begin to blink count the blinks then there will be a pause and it will blink again so it may blink 4 times then 2 thats a code 4-2 after that press the set again if and count if you get the same you have just that code if multiple codes just keep reading until you get to the original one.