How to Determine Wire Functions on Trucks
Question:
I have a pace trailer my interior lights worked with my Chevy 2500. I traded to a Ford F-250 now interior lights do not work. SomeonE told the aux power was on different pin all other lights and brakes work. What wire do we need to change on trailor
asked by: Heith
Expert Reply:
What happens on some later model year Ford trucks is that the 12 volt output to the 7-way is turned off when in park or even during gear shifting. The easiest way to test this is the Pollak 7-Way to RV Socket LED Circuit Tester # PK12741 which you just plug in and which lights up in regards to each function on your F-250's 7-way, including the 12 volt.
Otherwise you would simply use Cordless Circuit Tester # PTW2979 to determine which of the pins is the auxiliary 12 volt. Additionally, if you want constant 12 volt power you can always use 10 gauge wire # 10-1-1 and run a line directly from your truck's battery - via Circuit Breaker # 9510 - to your 7-way.
I have added a cut out from the help article I linked on trailer wiring which I recommend taking a look at which shows what the wire colors have traditionally been, though it is recommended to use the circuit tester.
Products Referenced in This Question
40 Amp In-Line Circuit Breaker - Perpendicular Mount Bracket
- Accessories and Parts
- Wiring
- Circuit Breaker
- 40 Amp
- Pollak
more information >
Pollak 7-Way to RV Socket LED Circuit Tester - Vehicle End
- Electrical Tools
- Testers
- Circuit Tester
- Tow Function Tester
- Black
- Pollak
more information >
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