gimpyrobb
dumpsterlandingfromorbit!
- 27,785
- 747
- 113
- Location
- Cincy Ohio
I was contacted by a member that needs some help and I am not very versed in troubleshooting the 939 protective control box. Here is what I was sent:
My symptoms: With the PCB box unplugged, the switches in off position, battery cable unhooked, I get the following when I connect the battery cable: ABS warning light on, Low Air Light on and buzzer, Parking Brake light on.
Other information: Severalmonth ago I drove the truck everything was fine. About a month later went to drive it and the batteries were dead (switches in off position). When I started charging the batteries as they got energy I got ABS warning light on, Low Air Light on and buzzer, Parking Brake light on.
I was able to start the truck and everything seemed to be innormal state no ABS light, no Low Pressure light, No parking brake light when put down, when the air came to pressure the warning buzzer went off. I could drive the truck everything seemed normal. The only problem was that the switch would not turn the engine off. I had to pull the emergency shutoff to stop the running engine.
I thought when the PCB was unplugged I thought nothing had power but guess I am mistaken in that thought. I did try a PCB that died on another truck, would not allow the truck to start, and got the same failures.
I also unhooked each wire from both switches individually and the symptoms did not change.
Where do I start or need to look at please? My son-in-law the mechanic is not available to help me right now but I do have good basic skills.
Thank you for your time and help.
If anyone could offer some help, I would really appreciate it.
My symptoms: With the PCB box unplugged, the switches in off position, battery cable unhooked, I get the following when I connect the battery cable: ABS warning light on, Low Air Light on and buzzer, Parking Brake light on.
Other information: Severalmonth ago I drove the truck everything was fine. About a month later went to drive it and the batteries were dead (switches in off position). When I started charging the batteries as they got energy I got ABS warning light on, Low Air Light on and buzzer, Parking Brake light on.
I was able to start the truck and everything seemed to be innormal state no ABS light, no Low Pressure light, No parking brake light when put down, when the air came to pressure the warning buzzer went off. I could drive the truck everything seemed normal. The only problem was that the switch would not turn the engine off. I had to pull the emergency shutoff to stop the running engine.
I thought when the PCB was unplugged I thought nothing had power but guess I am mistaken in that thought. I did try a PCB that died on another truck, would not allow the truck to start, and got the same failures.
I also unhooked each wire from both switches individually and the symptoms did not change.
Where do I start or need to look at please? My son-in-law the mechanic is not available to help me right now but I do have good basic skills.
Thank you for your time and help.
If anyone could offer some help, I would really appreciate it.
