Jomorisn

The A/C used to work fine in this truck but something hap[peded lately, When my air conditioner is on the fan on the engine doesn't engage and compressor short cycles if I unplug the wire to the left of the radiator the fan engages and it stays engaged and the compressor seems to run longer with the fan engaged. Is there clutch fan is there a relay that controlls the engine fan? Also is there a relay next to the APAD? Thanks in advance for any and all help

I will check the headlights work fine it I have no dash or running lights cab lights marker or tail lights I read there’s a pressure switch that can cause this problem but the headlights still work at a loss here I will chase the harness this weekend Thanks John

I did replace the relay and still have the same problem not sure where to go next any and all help is great thanks in advance

I cleaned all grounds and still have the issues. Maybe bad speedo?

I have a 20032 CH613 the dash lights and headlights running lights stopped working. Is there a relay for these? Thanks in advance any and all help is apreciated. thanks John

Vmac3, Is the communication connector the green and yellow wires? And thank you for your reply. Thanks John

I have a 2002 CH 600 with a 427 it has started with this problem of not starting or stalling when driving and sometimes starts right up and today it would not start for 45 mins and sometimes run for weeks with out an issue It shows codes 6 and 4 and the dash displays No Info it died today sat for about 45 mins fired and I was on my way . Could it be a bad ECM? overheating cooling and then starting back up when it cools down? I have posted this before and have cleaned all grounds and my isssue continues I don't think its a harness problem any and all help would be great thanks in advance Thanks Sick CH

I have a 2002 CH 600 with a 427 it has started with this problem of not starting or stalling when driving and sometimes starts right up and today it would not start for 45 mins and sometimes run for weeks with out an issue It shows codes 6 and 4 and the dash displays No Info it died today sat for about 45 mins fired and I was on my way . Could it be a bad ECM? overheating cooling and then starting back up when it cools down? I have posted this before and have cleaned all grounds and my isssue continues I don't think its a harness problem any and all help would be great thanks in advance Thanks Sick CH

I have a 2002 Mack CH 2002 427 it will run fine for weeks and then start stalling not starting until it sits for a while then start and stall lately will not stay running and I can't use the truck. it will show No Info on the dash and also throw 6-4 code I have cleaned all grounds that I could find. Can the VECM or the VECU cause these problems. Any and all help would great Thanks John

I have cleaned most of the grounds and will cleanup the rest. Thanks for taking the time to answer my post. I really appreciate it I will let you know how I make out. Thanks again John

I have a pair they on my Peterbilt now I will be changing to hub piloted and will message you when they are off in a month or so if you’re interested Thanks John

My speedometer works fine until I turn on my head lights then it reads high if i shut the truck off and lights and start up it works fine. Thanks in advance john

Does anyone know what the black junction block with 2 stud with wires attached next to the starter solenoid is called and what does it do Thanks in advance John

What is the J1939 link and when do i find it Thanks in advance John

My CH throws 6-4 code what is the J1939 link and where do I find this any and all help would be great Thanks john