davintosh

I just went through a bit of an ordeal getting our van wired up to pull a trailer, and I’m hoping to maybe help someone else who is needing to do the same from going down the path that I followed, which caused a lot of frustration and wasted a lot of time. The short of it is, if you need to add trailer lights to a Ford Freestar (or most any late-model Ford product), just buy the kit from the Ford parts desk; you’ll be glad you did.

Now the long version: Earlier this year we bought the inlaws’ van… a gray 2005 Ford Freestar minivan, well equipped, and very clean. It had 50 thousand miles on it! so they felt the need for something newer. We got a great deal on it — basically paying Dad what the dealer would give him trading it in on a newer Freestar. Added bonus; Dad financed it for us, so we have no monthly payment and no interest. We’re just paying it back as we’re able.

We were planning a short and slightly spontaneous vacation, and decided the weekend before leaving to take our camper — a 1988 Palomino Colt pop-up — along. The problem that arose was that the van didn’t come with a hitch or wiring for a trailer, so I dove into the project with only two days to get it ready. The hitch was easy, and not terribly expensive; it came from the local UHaul Hitchworld shop — Hitch number 36800, 1 1/4 inch receiver, class 2, 3500 max. weight, about $150 with tax. Four bolts into existing holes in the frame of the van, and that was done in about a half hour.

The guy at UHaul shop was a bit of a character, and when I picked up the hitch he mentioned something about the hitch being the easy part; the wiring… Oh ho ho, the wiring. He said it involved adding fuses and relays and wiring harnesses all over the vehicle. They had a kit to do it, but at $70 I figured I could get it done a lot cheaper. I kinda figured he was just trying to upsell a bit, and besides; how hard could it be? There were plug-in kits for most vehicles, and splice in kits for the others. In a way, he was right, but he was also very, very wrong.

My next stop was at the Ford dealership parts counter, where I found that a kit is available, but the guy made it sound like it’d be three or four days to get it, so I (foolishly) passed on it and started to search elsewhere. The Ford guy said that the auto parts stores usually carried aftermarket kits for that sort of thing, so I made the rounds to several other shops; nobody had a simple plug-in kit for the Freestar. All their books pointed to a generic spliced-in wiring harness, but I really hated to go that route, so I kept looking. And came up with exactly squat. I ended up buying one of the feared generic kits (for $30) and planned to spend the morning before our departure installing it.

I ran into trouble pretty quickly; a tag taped to the wiring inside each taillight warned against splicing trailer wiring there. Hmmm. The owner’s manual only reinforced that warning. Then I did something that caused the right taillight to go completely dead, which scared the daylights out of me. I got it back by turning the ignition on then off, which apparently reset the onboard computer, or something. Anyway, that made me decide then and there that the splicing method was officially a Bad Idea.

One thing I noticed when I dove into the splicing project was that there was a round 4-pin connector that dead-ended behind the rear bumper, just forward of the spare tire. I remembered something like that on the Aerostar van we used to have, and that trying to hook trailer wiring up to it didn’t work out. I tested the pinouts on that connector, and sure enough they were dead. So I hopped on the Internet Superhighway to see if I could find anything out about that connector. Sure enough, the connector is for the factory trailer wiring option, and is designed to work along with the trailer wiring kit available from Ford. There is no power to that connector though; to get it working requires three 4-pin micro-relays and two 20-amp fuses.

Time was still an issue, so I figured if I could come up with those three relays and two fuses, I could cut the connector and splice in a flat four-pin trailer harness and be on the road. But that was not to be either. After checking with three auto parts shops, I came up empty; one of them actually had a listing for the relays in their computer, but they were unobtainable. So I went back to the Ford dealer parts desk. There they had one relay of the type I needed, but could order more if needed; but if I’d be better off just ordering the kit. I think the guy said the relays were $21 a piece. Ouch. So much for that idea.

I thought briefly about hitting a couple of junkyards to see if I could scrounge up anything, but that would mean a lot of driving for only a chance that it could work, and the day was getting on. So, I bit the bullet and ordered the kit. $40, with overnight shipping. Dang; if only I hadn’t been scared off by the 3-4 day estimate I’d got earlier in the week… If only.

We did end up leaving on schedule, but with a borrowed vehicle — a 2003 Ford Excursion. 11.3mpg. If only we would have waited for the part. If only.

When we returned from our vacation, the wiring kit had arrived, so I dove in and installed it. Took a total of 5 minutes to complete. Open the hood, pop open the fusebox, plug the three relays and two fuses into the appropriate spots, close it back up, crawl under the rear bumper & plug the wire adapter/harness into the plug, and you’re done.

Lessons learned from all that?
1. Plan ahead. I knew I’d need to pull that camper at some point, so I should have had all that taken care of soon after buying the van.
2. Follow the dealer’s recommendation. I’m not entirely sold on this lesson, and it certainly doesn’t apply in all situations. But for trailer wiring on the 2005 Ford Freestar, the drop-dead easiest solution is to buy their kit. Period. End of discussion.

I’m sure there will come a time for someone that the Ford wiring kit may not be available, so here are the part numbers in case someone else wants to take a stab at it.

The Freestar Trailer Tow Electrical Installation Kit — Ford Part Number 3F2T-15A416-A — contains:
3 — 4-pin micro-relays, P/N 3F2T-14B192-AA
2 — 20 A fuses, yellow, P/N 1L3T-14A094-HA
1 — Trailer Tow Harness, P/N 3F2T-13A576-A
1 — Installation Sketch; P/N SK3F2T-15A416-AA (scanned image, large file; 1.6MB)

I’m convinced that the junkyard option would be a good solution for many people; just find a wrecked Freestar (or other Ford vehicle) and scavenge the relays from the fusebox. On the Freestar, the same type of relay is also used for the A/C clutch, the fuel pump, and the fog lamps, so the salvage vehicle doesn’t necessarily even need to be equipped with the trailer towing package. The fuses are standard 20 A yellow fuses, as are used elsewhere in the fusebox, and available at most any auto parts store. And the connector at the rear of the vehicle can be easily clipped off so that a flat-four wiring harness could be spliced in. Not quite as neat & tidy as the Ford option, but I’m sure it would work just as well, and might even save you a few bucks.

(full-resolution version)

You can see in the photo above that the relays used in locations 29, 30 & 31 are the same part as is used for the A/C clutch, highbeam, fuel pump, and fog lamp relays in locations 22, 23, 25 & 26, respectively. The relays are all marked “P6STD 7018 3F2T-14B192-AA”.

Legend for above fusebox diagram.

This entry was posted on Sunday, July 27th, 2008 at 11:25 pm and is filed under Cars!, Geek, Just Stuff. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.