I have a 1994 IH snow plow truck, single axle, DT 466 engine with allison transmission modle. # MD 3060 I have been fighting this problem for a couple years. Wondering if some one has experienced or know what I can do to bypass or repair. Problem is, if outside temperature drops to 40 or 30 degrees, the truck will not start, or shift into gear. I believe the problem is with the trans controller, truck has a t-handle shiter with gear selected icon, and trans. Monitor icon. When the ignition key is turned on, when working correctly, and the truck will start or shirt both icons will have a N in the display. But when not working correctly, and you turn on the key,both icon displays will have a vertical line with a angled hash mark tru it. When this happens, no crank, I can jump the starter solid and the truck will start, but will not electronically go into drive, even tho t handle has selected drive. I have removed and inspected both big plugs on the trans controller module, and fine no problems with pins or wires. To make truck start, or drive, I found that if I direct a electric heater towards the aluminum housing on the controller module, and warm it up about 5 minutes, the truck will start and drive in all gears just fine. The problem is definitely temature related, as it works fine in the summer, HELP, WHAT DO I LOOK FOR, TO TROUBLESHOOT OR REPAIR THIS PROBLEM?
Have you checked for good clean power supply voltage at the controller before and after the plugs? or checked grounds? I know you said temp related but I had a New Holland 1085 bale wagon computer give me all kinds of fits in cold damp weather and be fine on sunny dry days. Maybe a sensor on its way out throwing bad readings back to the controller? not too familiar with them but thats where I'd start
Aluminum housing on the controller module you say----30 years old-electrical-aluminum- expansion, contraction problem-either connections external at controller or connections internal at controller, or a combination of the two plus age.
Yes, I don't dought your conclusion, but ,how can I troubleshoot it, or where can I get it tested?
google searched MD3060 and vander haags has used ones and rebuilt, if its internal in the controller theres probably no real way of troubleshooting, you could try and open it up and inspect for loose pins or bad soldered connections on the board