I just got around to upgrading the wiring on my truck today and installing 8 ga. wire and an 85a. continuous duty solenoid. Everything went well until I tested it. I am using the hot lead from the trailer plug as the signal but it doesn't energize the solenoid. I have tested it with a meter and the signal wire has power,I did a continuity check on the signal terminal and the ground on the solenoid and all is ok there. I jumped the signal terminal to the battery and that seemed to work. My truck is a 2005 F-350 Lariat with camper and trailer packages. The trailer plug works fine. There aren't any problems with the truck wiring as I have tested EVERYTHING. Since the hot lead from the trailer wiring is hot and the solenoid works,what could I be missing?
Did you have your voltmeter on the voltage from the trailer plug when it was trying to energize the solenoid relay coil, or did you just measure the voltage at the output of the trailer plug with no load (open ended).
The trailer plug could show 12 or so volts (Battery Voltage) under no load conditions and then when loaded it may not be 12 volts due to high resistance in the trailer wiring circuit, thus it will not allow proper current (3A) to operate the relay in question....
jsmmv wrote: I just got around to upgrading the wiring on my truck today and installing 8 ga. wire and an 85a. continuous duty solenoid. Everything went well until I tested it. I am using the hot lead from the trailer plug as the signal but it doesn't energize the solenoid. I have tested it with a meter and the signal wire has power,I did a continuity check on the signal terminal and the ground on the solenoid and all is ok there. I jumped the signal terminal to the battery and that seemed to work. My truck is a 2005 F-350 Lariat with camper and trailer packages. The trailer plug works fine. There aren't any problems with the truck wiring as I have tested EVERYTHING. Since the hot lead from the trailer wiring is hot and the solenoid works,what could I be missing?
Jeff
I'd suggest you place the voltmeter across the solenoid signal terminal and ground when you think it should be energized. You'll either get about 12v and the solenoid will be pulled in unless it's defective, or you'll get 0 volts indicating an incomplete circuit, or you'll get something in between, indicating either a bad ground or connection somewhere.
If you take a long extension wire from your main battery ground and connect it to your voltmeter negative, then start from the battery with the voltmeter positive and work your way around the circuit starting at the main battery positive terminal till you get to the point where the meter reads less than full voltage, you'll find the location of the problem. In doing this, normally you wouldn't stop when you've reached the signal terminal of the solenoid as it's possible there's a bad ground except you've verified the solenoid works with a positive jumper.
I assume you have the solenoid grounded to the chassis of the vehicle and that it's a 3 wire solenoid. Where did you mount the solenoid and how many terminals does it have?
2001 GMC Sierra 2500 SLE Short Box 4 door Extra Cab
6.0 Vortec, 4L80E Auto Trans, 3.73 rear. 4X4. Timbrens, Rancho 9000's. Hidden Hitch front and Happijac rear tie downs. 1985 Frontier Camper.
Member/Editor of Victoria Motorcycle Club and ASHRAE
Offline
