New to me 1979 Bigfoot

[WillyBigfoot]

Hi all! So I just purchased a 1979 Bigfoot 17' trailer. Seems to be mostly original with some cosmetic upgrades as far as I can tell.

Anyway my first question is about the signal lights etc just to get it on the road. Tow vehicle is a 2000 Silverado Z71 with a 5.3L. Tested the 7 pin plug and everything seems to check out. On the trailer however some minor issues as follows:

Both Running lights work (just talking rear lights, will diagnose marker lights later)

Right signal works but left doesn't

Right brake light works..... kinda. When running lights are on light turns off when brake is pressed, when running lights off light turns on with brake pressed.

Left brake light doesn't work ( no change when pressing brake)

Anyway just wondering if anyone has any opinion on where to start with this! It seems like there is only one bulb each side with dual filaments, on a side note what bulb should I be using ? As well any input is welcome on things to check or common problems on this trailer. This is all new to me ! Thanks in advance and excited to be part of the community!

[Jack L]

The first thing I would check for ts corossion on both the 7 pin plug ant the trailer sockets. Clean all the sockets then check for power with a meter.

[WillyBigfoot]

Thanks Jack !!! So I did that and the truck side is fine.

As far as the trailer there doesn’t seem to be continuity on the prong for the left signal, but the others work. I can try cleaning again but perhaps there is a wiring issue ? Or would a bad bulb do the same ?

[Michael Pupeza]

In my 93 17 CB, under the front driver side seat, near the front, ahead of the water heater, there is a bolt head with a big washer in the floor. For some reason, this appeared to be some kind of ground connection for the lights and when wiggled seemed to clear up a problem. I suspect that the grounds are bunched under there to the frame from the front trailer wiring. Check that!
I never did take it all apart to check and fix properly as it was working again after I wiggled it and then left it. My bad!
But, all seems well again.
Early Bigfoots were not all made the same, and not all great!
Good luck - Mike .....>

[Jack L]

A bad bulb, a bad socket, or a wiring problem could be the issue.

[WillyBigfoot]

Originally Posted by Michael Pupeza

In my 93 17 CB, under the front driver side seat, near the front, ahead of the water heater, there is a bolt head with a big washer in the floor. For some reason, this appeared to be some kind of ground connection for the lights and when wiggled seemed to clear up a problem. I suspect that the grounds are bunched under there to the frame from the front trailer wiring. Check that!
I never did take it all apart to check and fix properly as it was working again after I wiggled it and then left it. My bad!
But, all seems well again.
Early Bigfoots were not all made the same, and not all great!
Good luck - Mike .....>

Ok thanks Mike I will check that for sure!!

[WillyBigfoot]

Originally Posted by Jack L

A bad bulb, a bad socket, or a wiring problem could be the issue.

Thanks Jack! Yes I need to dive in more when I have time. Any insight to the bulb that should be installed? Like a number or whatever??

[WillyBigfoot]

Also what do you use for cleaning corrosion on the plugs??

[WillyBigfoot]

Just an update. Think I figured it out! Got the plug on truck sorted as well as the rear lights like running and signals etc. Just have to figure out all the marker lights as they're not working. Likely bulbs or just some wiring or corrosion etc. Thanks again for all the replies!

[NJNS]

Hey Willy,

What did you end up doing to get them sorted. Having similar issues with mine.

Thanks!

[WillyBigfoot]

Originally Posted by NJNS

Hey Willy,

What did you end up doing to get them sorted. Having similar issues with mine.

Thanks!

Hey NJNS!

Basically i made sure the tow vehicle end of things was working. You can use a multimeter or I actually bought a 7 pin tester at Princess Auto for $10. Research 7 pin plug and what all the prong functions do. Also there were a few fuses etc I had to replace on my truck, not sure on your tow vehicle but research that too to see what prongs should have power or continuity depending on everything. For example until I installed a certain fuse I knew my 12v prong wouldn’t show its working.

After that move to the trailer end of things. I started with my pigtail , I took it apart being careful to note which color wires went to which prong ( in relation to their function on a 7 way plug diagram , it’s easy to look up). And then tested continuity by touching the ground wire and each other wire. If there’s no complete circuit you can troubleshoot from there , in my case it was mostly corroded wires at the light which I could splice a new light on or pigtail the wiring.

I also just took a car battery at one point and at the 7 prong pigtail wires of the trailer attached negative to the ground and then went around touching positive to all the other functions to see if they would work.

I recommend the 7 prong tester from Princess Auto to sort out the truck end of things. It was cheap and was easier than when I used a multimeter.

Hope this helps ! I’m no pro it’s all new to me but slowly I plugged away and figured it out