I need some help with my glow plugs. Its always started even in cold weather. Now it cranks and cranks and finally starts. All fuel filters new and new pump. 1st i have no light on when starting on monitor. And i believe its never came on the monitor that i ever noticed ever. 2nd i checked for power at valve cover no power when key is on position. 3rd i checked the relay its good. I had no power to it so found out theres a fuse behind the fuel pump which was bad and i replaced it.Now relay has power. Have power all the way till it gets to the relay which feeds the glow plugs after that nothing.all other fuses have been checked. what eles is there to check. i talked with a cat mechanic which has been helping me over the phone he seems to think its been disabled threw the ecm from the factory. Or someone turn it off on the ecm itself. Is that possible? I bought the machine with 50hrs on it.It came from a auction. I havent had it plug to a computer yet thats next. The machine has 4025hrs on it and runs great no smoke and lots of power.
You should get ET hooked up to it and have them download a Product Status Report. I'm not sure that the glow plugs are a selectable parameter though. From memory the signal to the ECM that should energize the glow plugs comes from the coolant temperature sensor. Post a Serial Number and I can look it up. Have you tried supplying 12v to the relay coil to check if it pulls in and energizes the glow plugs.? F793 Orange coming from the engine ECM is the wire you need to energize. Do that and you ought to hear the contacts of the relay click provided that the ground on wire 202 Black is good.
No i ohm it out. ill try that next. Is it possible that the coolant temp sensor could be bad? Its reading temp on the monitor. Heres the serial number DHTAW00913
Best way is a test light that draws significant amperage. If you have corrosion somewhere it might show OK on a continuity test but won't pass the required amount of current. Check you message inbox. Electrical schematic incoming.
Thankyou ill check it out and keep you updated what i find.