Low voltage @ 7 pin plug

[pgleavitt]

My problem is that at the constant hot wire for charging the trailer while plugged into the truck I only have 9. 4 volts. I have used this as a source to power some piaa backup lights in the past. Any one have any ideas why I would see low voltage? I have disconnected the backup lights and gone up stream on the wire to the the location where it comes out of the harness under the back of the truck and still only see low voltage. If it's any help it's the red wire with orange tracer and located on the lower pin area of the plug.

 

[B.G. Smith]

There is a fuse in that line somewhere, probably in the PDC under the hood, check the fuse and the connections there. bg

 

[klenger]

Are you getting low voltage with nothing plugged in at the plug? If so, then there is a problem. If the low voltage is the result of a heavy load, then it might be normal as the wire is not very heavy.

 

[pgleavitt]

The low voltage is with nothing plugged in. I already tried to switch the 40 amp fuse and a relay under the hood in the PDC and problem still exists. I was suprised on how small the feed wire to the plug is for what it's supposed to do. I guess I will just run a heavier fused wire from the battery to the plug and call it good.

 

[K5IP]

Running a heavy wire directly from the battery to the connector is always a good idea especially if dry camp. I ran a #8 wire for this purpose and it serves me well on extended trips (dry camping) through Canada and Alaska.

Klinger is right though, under no load conditions (not connected to anything) you have a different problem if you are only reading 9. 4 VDC open circuit.

Perhaps you have a measurement problem.

1. Verify your meter operation by measuring the vehicle battery at the battery. (engine off, about 12. 5 Vdc)

2. Be sure your meter ground return is good by running a ground return back to the negative post of the battery. Measure the connector voltage using this ground.

3. If connector voltage is still low, work your way back toward your fuse and relay making measurements untill you find the full battery voltage. Once you find the full voltage, you have found the problem.

4. Or, just do as you indicated, run a new wire.



It's always fun to really find out what happened thouogh.

Rog