Lights Out

Ha ha. You were right. On second one I crossed green and whites. I fixed and the fuse surge problem went away. Unfortunately front lights lit and all but one in the back are now out. That is nuts. Just one in the back works out of 7. I check with check light and no power. They all worked before I changed them all. I changed them all because they were all weathered. NOW I do want to kick a reindeer.

Hey Clark, look on the bright side, you may not need to check all 11, you may find the problem on the 1st or 2nd one you look at.

Don't blame yourself either, the problem may be in the fixture itself and not a wiring problem. Don't rule out a defective fixture, so look at those too as you go around.

Yeah - I need to go the route of checking all 11 lights. Call me Clark. Thanks. I'll be back.

cs2kplus wrote:
ok.....checked my truck. A 15 amp fuse was out. I replaced. The lights all came on - for 5 seconds - and out they went. Fuse was blown. Just like Clark. If it was Xmas I'd be kicking some lawn ornaments. One thing to not...I only had one fuse left to use. It was one that had a "z" element in it as opposed to the more robust looking one I replaced. But...its rated for 15 amp nonetheless - so should not matter. Whats going on? Why would they light - then blow a fuse? Too much juice being outputted? Bad ground? looks like I'll need a buch of 15 amp fuses testing this.

I would have expected it to pop faster than 5 seconds....

It is possible that you pinched a wire and it is shorting out against the metal of the trailer. In the trailer plug you can check for continuity using a test meter between ground and your 12v source wire.... If there is continuity, it is shorted.

How did you make the wire connections? Crimp caps or solder and tape? If there are any copper wires sticking out of your connections it could short there as well.

It is very tempting... But whatever you do, do not put a bigger fuse in your truck... If it had a blue 15amp fuse make sure you replace it with a 15amp fuse. Going to a larger fuse can cause serious damage.

There is a high resistance short circuit somewhere.

ok.....checked my truck. A 15 amp fuse was out. I replaced. The lights all came on - for 5 seconds - and out they went. Fuse was blown. Just like Clark. If it was Xmas I'd be kicking some lawn ornaments. One thing to not...I only had one fuse left to use. It was one that had a "z" element in it as opposed to the more robust looking one I replaced. But...its rated for 15 amp nonetheless - so should not matter. Whats going on? Why would they light - then blow a fuse? Too much juice being outputted? Bad ground? looks like I'll need a buch of 15 amp fuses testing this.

Sounds like you have a short somewhere and the fuse in the truck blew before any lights came on. I would go back to each light and check the wiring and also the fuse in the truck.

The lights are wired in parallel not series... So you won't have the Griswald Christmas light issue where one light goes out they all go out.

What is strange is that all the lights you installed are not working. These are marker/park lights and would be powered from the wire harness that plugs into the truck. If one or two lights did not work I would say they are bad or installed incorrectly. Since none of the lights are working I would start by checking the source. As others have mentioned, get a test meter and start at the plug that goes from the trailer to the truck. First check voltage between "Pin 1" and "Pin 4". Then check for voltage between "Pin 1" and "Pin 3". Of course make sure the headlights are turned on the tow vehicle while testing with the meter.



If no voltage found, look for a blown fuse in the tow vehicle. What year, make and model truck?

If you have voltage there... Then check for voltage at one of the lights you installed.

I will have to go out and check all connections.

You will have to figure out if there is voltage at the connection to the lights. If not, where does the power stop. A voltmeter or a test light would work. If you have one of the old lights that is good you could use that as a test light. The first step is to determine that the test light is good.