Towing Electrical Wierdness

[DrewSK]

Hi all, coming out of the lurking ranks as we just purchased a 16ft 1987 Scamp.

When we picked it up, I didn't have the correct converter 4pin on my truck to 7 pin on the scamp. I stopped by a Menards for a converter, but in the dusky light of the parking lot I wasn't able to get a good ground. Drove home 30minutes without lights and managed to back the Scamp down our alley (a whole other story, first back up adventure ever). During the drive when I applied the brakes with the turn signal on, my 2001 Ranger's blinkers clicked to the fast blink pattern that usually signals a light being out.

After some sanding and extending the ground wire from the 4-7 converter finally got a good ground- some sign of lights! However when I flip the blinker on for either side, the rear lamps blink on both sides and if I apply the brakes with the blinker on the lights again click with the fast pattern. I'm guessing some of the wiring is switched around. Has anyone had this come up?

My next steps are giving the previous owner a ring and getting my multimeter out while checking with the scamp wiring diagram.

[Bob Miller]

I had a similar experience with a Ford Windstar of about the same age. Seems that the lights were "Ground Seeking" that is, they were always hot and closing the circuit made the ground through a solid state controller. I had to add a special converter to make it all work. You might find out if that's what you need. Most auto supply stores carry them. Be sure it's for a FORD, and not just a 2 to 3 light converter.

[Ron in BC]

You shouldn't need anything special. I use Ranger-Scamp wiring. I added a Hopkins 7 pin adaptor. The Ranger 4 pin connector just plugs into it. The extra wires of course aren't really needed unless you have brakes or want to add a charging circuit.

So the 3 basic wires (plus ground) on the Ranger just do the same thing via a 7 pin connector. There's lots of potential for a wire to have been changed over the years.

I use a multi-meter for trouble shooting all the time but for this situation, confirming that the trailer wiring is correct, I use a 12 volt source, wire by wire. Much more graphic and easier to sort out what wires powering what.

Ron

[Dennis Clinton]

I found on my Scamp that the factory did not follow the standard trailer wire color pattern. Also check the 7 pin trailer end connector-has it been changed or is it molded on? If it's been changed, pull it and check the connectors. Also clean the bulb fittings on the trailer. Sometimes there's a bad ground at a bulb fitting, causing the power to back feed through the other filament.

[DrewSK]

Thank you all 100x!

I've taken the trailer 7pin plug apart, my ranger's 4pin, and the adapter. Adapter is new and in good condition, the other 4 plugs aren't awful... but will be cleaned for thoroughness.

Good idea on the bulb fittings Dennis, I'll check those as well.

If all is spicnspan and still no dice, I'll pull out the multimeter and get testin'! Thanks again all, I'll report back when the culprit is found.

[Hambone]

Drew,
Start with the Rangers 4 plug, does that work correctly?
Then check 4 to 7 wiring to make sure they all go to correct places on Scamps wiring. Then make sure you have ground on truck wiring and on trailer, then check all bulbs and bulb wiring, for corrosion, grounds.
On mine one time it was the grounding rivit inside one of the rear taillights was corroded.
Tom

[Roy in TO]

My Ranger did not come with any wiring. Bought an adaptor meant for the Ranger that you simply insert between two connectors in the rear wiring harness to get a 4 pin connection. Then bought the hoppy 4 and 7 pin connector that you plug the adaptor into. You might want to check into a HD flasher that will handle the extra load.

[Carol H]

Originally Posted by DrewSK

I've taken the trailer 7pin plug apart, my ranger's 4pin, and the adapter. Adapter is new and in good condition, the other 4 plugs aren't awful... but will be cleaned for thoroughness.

Check the wires where they go into the vehicles plug. If they or the screws in the back of the plug have any corrosion it can result in weird and not so wonderful performance.

[DrewSK]

Thank you all for your help! Took a look at it tonight:

- checked the voltages coming from my truck. All good.
- took apart plug on trailer for cleaning
- while it dried, tested all the lights w a 9v battery I had kicking around my garage. They all worked perfectly.
- reassembled plug after cleaning and tried it with my truck- everyone is happy!


Satisfied with the first very minor repair to my scamp. This is why I love diy.