Originally Posted by moparx
my one buddy has a cub cadet tractor that has a 3 cylinder diesel engine. [i can't see anything on any tags who made this engine]
the problem is the starter will not crank over. battery is good, and all wiring from the key to starter/glow plug relay checks good, plus all grounds, starter, and starter battery cables check out as well with no voltage drop.
attached, is a diagram showing the glow plug timer preheat module. it has 12v on the outer top row terminals in run and start.
the center terminal shows zero volts in run, but only 5.22v in the start position. if 12 volts is applied to the center terminal, which goes to the starter solenoid [almost identical to a mini-starter], the starter spins over as it should, and the engine starts.
is this module bad ?
the wire going to the glow plugs [from the relay] has 12v when key is turned on, and after xx seconds, the relay kicks, voltage to the plugs turns to zero, and the dash light for the plugs goes out [as it should ?].
i know nothing about diesel starting systems. TIA ! bow
beer


The timer is working correctly and has nothing to do with engaging the starter. Testing this control plugged in can confuse you. Your wire colors and functions should be this. Green goes to a coolant sensor. It is a ground circuit and applies a ground to the timer.This tells the glow plug timer control the engine temperature. If it is warm enough the controller wont activate the glow plugs. Red with a black tracer is a 12 volt keyed power source. The solid Red applies a ground to the glow plug relay. The Orange with a white tracer goes to the starter solenoid activation wiring. I am pretty sure when the tractor is normally starting when voltage is applied it cancels the glow plug timer function. The way you describe it right now I believe the timer is working correctly. If the colors I told you here are correct I can coach you the rest of the way. I think. [lol].

Last edited by NITROUSN; 05/05/20 08:42 PM.