4 pin TV 7pin Scamp '89 16'

[Steve and Rosemary]

Hi all! I posted these questions under a general "basic towing questions" so I'm sorry if this is a duplicate for you. Here goes:

This is a long post, so feel free to just read the red text to get a general idea. I hate to waste other's time! Our Explorer came with a tow package but we're getting a bigger hitch -- no problem. Also, it came rigged with a flat four plug and the Scamp has a flat 7 point (6 around 1 I think). So at the trailer place, we got what I think is a "T One" converter to go from four on the Explorer to seven on the trailer. It's pretty obvious how it works -- the trailer plugs into one end that will be mounted on the hitch; and the Explorer's flat four goes into the piece on the adapter that it will fit.

It's at this point that we have questions. There are four additional wires coming out of the "vehicle" end of the adapter. The colors are white, black, yellow, and blue. As I understand it, the white is a ground, the black is for batter power, the blue is for brakes, and I'm GUESSING that the yellow is like purple -- for auxiliary. Question One: Am I right about my colors on the four extra wires on the adapter? white-ground, blue-brakes, black-battery power, yellow-auxilliary like purple.

So we're not going to do the brake controller yet, but we will eventually. The ground is pretty self explanatory. I doubt we'll use the yellow. But we DO want to use the black so we can "charge" the trailer while we're in transit (i.e., keep the 3-way fridge running off of DC power to keep food cold). So far, I have read that you have to run the black wire up to the battery. At this point, things get foggy again. Question Two: Does the black wire from the adapter need to be connected to the positive or negative post of the Explorer's battery? This seems like a big deal to me, but there seems to be some confusion!

Also, my mechanic wants to put a fuse in and I'm sure that's a good idea. The guy at the trailer place mentioned that, so no problem there. But I've also heard talk about "isolators" and I can't really figure out if I need one or not, or if the Scamp already has one built in, or where to put one. I haven't asked my mechanic, so he may know but I figure I've written this much.... Question Three: Do we need an isolator, does the Scamp '89 16' already have one, where do we put it?

Question Five: Please offer deailed instrucitons on how to wire for the brake controller. I've seen a description on here that seemed very good but now I can't find the post! We don't have the controller yet but while the TV is up, we might as well get the wiring in, right?

And with that, I think my questions will be answered. If you have links to other topics or websites, and/or photos that can explain this well or ANY suggestions, we'd both be very thankful!

[Robert Johans]

Here's the color code of most 7-pin TV/trailer set-ups:

Black = power
White = ground
Green = clearance and tail lights
Brown = right turn
Red = left turn
Blue = brakes
Yellow = auxiliary

An inline fuse between the TV and the on-board trailer battery is a must. Though newer vehicles don't always need them, isolators are highly recommended, though not absolutely necessary.

Typically, and most simplistically stated, the black/power and white/ground wires from the TV are connected to your on-board trailer battery. Your cabin 12V needs are supplied by the on-board trailer battery.

[Frederick L. Simson]

It's at this point that we have questions. There are four additional wires coming out of the "vehicle" end of the adapter. The colors are white, black, yellow, and blue. As I understand it, the white is a ground, the black is for batter power, the blue is for brakes, and I'm GUESSING that the yellow is like purple -- for auxiliary. [b]Question One: Am I right about my colors on the four extra wires on the adapter? white-ground, blue-brakes, black-battery power, yellow-auxilliary like purple.

You are correct; but I don't understand the purple comment.

The most common use for the Yellow wire is to activate the trailer's Back-up Lights, if your trailer has them as part of the tail-light fixture. Most plug-and-play adapters don't include the back-up lights, so I had to fish inside my quarter panel to splice into the car's back-up circuit.

[Frederick L. Simson]

[b]Question Two: Does the black wire from the adapter need to be connected to the positive or negative post of the Explorer's battery? This seems like a big deal to me, but there seems to be some confusion!

Also, my mechanic wants to put a fuse in and I'm sure that's a good idea. The guy at the trailer place mentioned that, so no problem there. But I've also heard talk about "isolators" and I can't really figure out if I need one or not, or if the Scamp already has one built in, or where to put one. I haven't asked my mechanic, so he may know but I figure I've written this much.... [b]Question Three: Do we need an isolator, does the Scamp '89 16' already have one, where do we put it?
[color="#ff0000"]

Answer Two:

• The Black wire from the adapter needs to be connected to the POSITIVE post of the Explorer's battery.

Answer Three:

• An isolator is a good idea.
• The '89 Scamp 16' does NOT already have an isolator.
• You put it between the Explorer's battery positive post and the black wire from the adapter.

[Frederick L. Simson]

[b]
Question Five: Please offer detailed instructions on how to wire for the brake controller. I've seen a description on here that seemed very good but now I can't find the post! We don't have the controller yet but while the TV is up, we might as well get the wiring in, right?

If you do what I did, you go to Camping World and pay the nice man to do it all for you.

Um, whatever happened to [b]Question Four?

[Steve and Rosemary]

Thanks for your help everyone! We're definitely more on track than we were before. Looking to have them wire it up and install the hitch tonight/tomorrow. Maiden voyage will be next weekend, but we plan on driving her around the block a few times to make sure it all works.

Speaking of which -- anyone know of any forums for beginner towers? This is will be the first towing experience for one of us... Thanks again!

[Roy in TO]

anyone know of any forums for beginner towers? This is will be the first towing experience for one of us

This is a pretty good place to start, lots of info has already been shared by others.

[Steve and Rosemary]

Good news, everyone! We got the hitch on with the converter and it seems to be working. We're going to hook the Scamp up and make sure her battery is getting charged while in transit but I'm sure it will be shown that everything is sound.

One quick story, just because we both think it's a bit weird.... When we first got the tug back with its new hitch and 4 to 7 pin adapter installed, we plugged in the Scamp to test the outside lights. Car running, plugged in, all the lights worked fine. Then we turned the car headlights on. The running lights in the back worked, as did the left hand (road) side running lights, brake light, and indicator. On the right (curb) side of the trailer, the only thing that worked was the rear running light. No brake light, indicator, or side running lights. We checked the bulbs on the curb side and that had a positive effect. The running lights all worked. But the brake and the indicator lights still didn't work on that side. So we undid the light cover on the right (curb) side in the rear and noticed that we couldn't get the second light bulb out. We had to put a bunch of WD40 on it so it would push in. Well, eventually it came out and we proceeded to push it in and out to work the spring. We put the bulb from the other side in there and then everything began to work perfectly everywhere. Headlights on the TV, back and side running lights, brake lights in the rear and indicator lights -- it all worked fine.

So I don't know what was going on but it seems like it has something to do with that second bulb...? Makes very little sense to me.

Speaking of bulbs -- we bought two new ones for the rear lights and within minutes they began to melt the light covers. We checked the manual and it says you need L1157s and L1141s for the rear lights, and L57s for the side running lights. We haven't been able to find L1141s yet (and this was the light bulb on curb side that we struggled to get out initially) and it was the L1157s that were melting the covers. Any ideas on how to fix this? I wonder if the covers are sitting too close for some reason. Is there some kind of spacer or something that should exist between the light cover and the trailer? If there is, we need to get one!

Well, anyways, thanks again for all your help and suggestions. We're still planning on taking our first voyage in a couple of days. Photos will follow for sure!

[Frederick L. Simson]

So I don't know what was going on but it seems like it has something to do with that [b]second bulb...? Makes very little sense to me.

Speaking of bulbs -- we bought two new ones for the rear lights and within minutes they began to melt the light covers. [b]We checked the manual and it says you need L1157s and L1141s for the rear lights, and L57s for the side running lights. We haven't been able to find L1141s yet (and this was the light bulb on curb side that we struggled to get out initially) and it was the L1157s that were melting the covers. Any ideas on how to fix this?

[b]1157 Bulbs are DOUBLE filament bulbs. In a 2 bulb tail light fixture, they are the [b]Bottom bulb, and are the Running Lights (dim filament) AND the Brake/Turn Signal (bright filament).

[b]1141 Bulbs are SINGLE filament bulbs. In a 2 bulb tail light fixture, they are the [b]Top bulb, and are the Back-Up lights (bright filament). 1141 bulbs are an older type, and can be difficult to find. [b]1156 is a newer cross-reference replacement for 1141.




DO NOT PUT AN 1157 BULB INTO AN 1141 SOCKET!
DO NOT PUT AN 1141 BULB INTO AN 1157 SOCKET!