Sensor ID, smokling wire and Headlights on all the time
#1
06-23-2012, 11:51 AM
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Sensor ID, smokling wire and Headlights on all the time
Troubleshooting an electrical problem. 1986 F350 6.9L
First indication of trouble was I found the headlights came on and staid on without the headlight switch turned on. I disconnected the batt until I could work on it.
Weeks later attempting to start and a wire starts smoking. This wire leads to a two blade sensor which is 4 inches to the pax side of the throttle solenoid and sits just ahead of the pax side front glowplug. The sensor is attached to an X shaped wiring harness pigtail with black colored connector.
One of the connectors on that pig tail ( gray) has already been by passed(?) and wasn't connected when I got the truck. The connector to the sensor(black) was melting and smoking after an attempted crank. I guess a shorted sensor however I'm unsure what sensor this is and if it is also related to the headlights coming on when every thing was shut off.
1.) What is the sensor with the black connector and why is it melting?
2.) What should the gray pigtail connect to?
First indication of trouble was I found the headlights came on and staid on without the headlight switch turned on. I disconnected the batt until I could work on it.
Weeks later attempting to start and a wire starts smoking. This wire leads to a two blade sensor which is 4 inches to the pax side of the throttle solenoid and sits just ahead of the pax side front glowplug. The sensor is attached to an X shaped wiring harness pigtail with black colored connector.
One of the connectors on that pig tail ( gray) has already been by passed(?) and wasn't connected when I got the truck. The connector to the sensor(black) was melting and smoking after an attempted crank. I guess a shorted sensor however I'm unsure what sensor this is and if it is also related to the headlights coming on when every thing was shut off.
1.) What is the sensor with the black connector and why is it melting?
2.) What should the gray pigtail connect to?
#3
06-26-2012, 08:43 AM
Logistics Pro
Sounds as if the high idle cellinoid might have shorted out. It runs off the temp sensor that you are talking about, along with the cold timing advance in the pump, which could have gone bad. On the grey connector, do you have a tach? The non tach trucks have the wiring for the tach hook up, and it is located at the front of the engine.
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06-27-2012, 11:03 PM
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Sensor ID continued
Thankyou FarmerT.
Apparently some time in the past there was a problem with the cold idle advance solenoid and a past owner wired it to a toggle switch in the cab. I really need to take a day on go to the farm and look my bad 7.3L to see how it is wired. I might be able to get serviceable parts from it.
I don't have a tach in the F350 but the gray connector may have been attached to the fast idle solenoid as it too shows signs of melting. The wiring harness in question connects to the fuel pump as well so based on what you've said I could have any of the three components shorted. This is a great help --Thanks!
Apparently some time in the past there was a problem with the cold idle advance solenoid and a past owner wired it to a toggle switch in the cab. I really need to take a day on go to the farm and look my bad 7.3L to see how it is wired. I might be able to get serviceable parts from it.
I don't have a tach in the F350 but the gray connector may have been attached to the fast idle solenoid as it too shows signs of melting. The wiring harness in question connects to the fuel pump as well so based on what you've said I could have any of the three components shorted. This is a great help --Thanks!
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