Troubleshooting Working Lights on 2003 Sundowner Horse Trailer Not Working

Updated 03/13/2019 | Published 03/12/2019

Products Featured in This Question

LCD Digital Circuit Tester

(28)

$27.73

10 Gauge Wire - Blue Primary - Per Foot

(109)

$1.91

Deka Heat Shrink Butt Connector - 12-10 Gauge - Nylon Insulation - Yellow - Qty 5

(1182)

$8.79

Question:

2003 Sundowner horse trailer working lights not working Brakes, turn all work but the interior,side door, rear working lights do not come on... Any advice provided would be great! I am pulling it with a 2016 Silverado 2500hd. Thanks

asked by: David

Helpful Expert Reply:

It sounds like you aren't getting 12V power for the lights on your trailer. The best place to start is the 7-Way connector on your 2016 Chevy Silverado 2500. Check the pin in the 1 o'clock position on your 7-Way with a tester like the part # PTW2992. If you have constant power on this circuit then the problem is on your trailer but if you don't have constant power that either means you need to turn the vehicle on (sometimes the 12V turns off when the ignition is in the off position) or the fuse for the 12V power needs to be changed (location 2 in your engine compartment fuse block).

If the problem is on your trailer then use that circuit tester to probe different areas in the wiring to see where it loses power. There could be some places where the wiring is damaged or bent so you would want to replace them with 10 Gauge Wire # 10-1-1 and Butt Connectors # DW05745-5.

Let me know if you are still having problems and I can help you troubleshoot further.

expert reply by: Jon G