Project Ford E350 Tow Rig: Part 3 – Step into the light…

Just like the Edge CTS2 Insight reader, this is a really complete kit. This particular kit includes an EAS control expander to hook into the CTS2 EAS bus so that it can be controlled from the CTS2 display. It includes a heavy duty wiring loom an automotive relay, as well as a switch if you don’t want to use the EAS system (or you could have purchased the light without the control kit).

And, of course, it includes zip ties and stickers, because those are required for installing anything on any vehicle, ever.

close up of two broken square driving lamps attached to bumper
These are the driving lights on the van. They have seen better days.

I have no idea how many years the driver-side lamp has been busted out. I know the passenger-side lamp has been busted out for a few years, because I busted it out when I accidentally crashed my E30 into the van. Don’t ask unless you want me to punch you in the throat.

The switch that controlled these driving lights has been flaky for years, too, so I never even used them. Most of the time I was just hoping not to hit anything in the dark. That was about to change.

rats nest of wiring under dashboard
Remember that rats nest of wiring I talked about in Part Two? Here it is.

I almost passed out when I pulled the lower cover off and found this. No wonder the alarm and remote entry system goes bananas once in a while. I mustered my courage and spent the next few hours carefully dissecting this mess to remove the gauge pod pillar and the switch and wiring for the driving lamps. Thanks to Edge, this would get a lot easier.

red, black and blue wires with push-on connectors and round switch in background
You can see the circular lighted switch in the background.

Depending on whether or not you use the EAS integration or the switch, you basically just connect the harness to one or the other, and off you go.

looking under dashboard with edge harness coming through firewall into view
The van makes getting wires through the firewall a little tricky…

You really only have two choices if you don’t want to make new holes. You come in through the floor or in through the “top” like you see here. The caveat to the top is that to get over to the door-side of the vehicle you have to get past the steering column, which can be tricky.

Ironically, inside the engine bay you end up with the same situation. If you want to get from the passenger-side of the engine bay under the vehicle to the driver-side, you also have to try to carefully avoid the steering column, or hope you have LOTS of extra wire. I could have easily extended the harness with the tools I had, but since I was only going to use the switch and not tie into the EAS for the light bar, I just went under the center of the dashboard under the radio and avoided the steering column all together.

relay zip-tied to vacuum block in engine bay
The included relay was simply secured to the firewall area with a zip tie.

The wiring is secured with zip ties in several other places, so the relay is not really hanging from the tie that much. However, it should be regularly inspected to make sure it doesn’t fall off. A more secure mounting can easily be devised.


  1. Spray Boeshield in all freshly drilled holes for rust protection. It will save you a lot of frustration down the road.

    1. @DocWalt we had looked at that option. The bottom of the E350 bumper is not flat and also is not wide. It actually steps down to a lip which reduces the mounting area. If you look at the picture where the light bar is installed, you can just make out the nuts on the bottom side of the bumper. When it’s just the nuts under there, it’s not a problem. In order to install the entire light bar below the bumper and still have sufficient adjustability, we would’ve needed a more complex mount. Then you have the difficulty of dealing with the wiring having to get around the lip and so on and so forth.

      We also considered on top of the bumper where the old lights were. But, again, the lack of a flat surface would’ve made constructing the mounts more difficult.

      I agree that there is a definite airflow sacrifice here. In towing performance thus far we have not seen any issues with the transmission temps, and the light bar is more blocking airflow to the extra trans cooler than the radiator. The vans are not intercooled. Once the summer comes on and we make longer tows we’ll get a better idea as to whether or not it’s a problem. Fortunately it’s just four bolts to undo and one wiring connection and the light bar is removed if it turns out to be a problem.

      There’s also the roof 🙂

    2. Isn’t this a diesel? Can’t see how you would need that much cooling unless you were running it during the day in the middle of the desert.

      1. It is a diesel, but it’s used primarily for towing, so the transmission cooling is somewhat important. It does routinely get into the 90F range here in the South East, and there are a couple of decent mountain climbs depending on which direction you head (for example, Monteagle between Chattanooga and Nashville). That being said, I’d think that this is not going to make a meaningful difference in cooling. Fortunately I have the Edge CTS2 Insight display to tell me if something is wrong!

  2. Wow, the light output from the headlights looks great! Hopefully you got em aimed right 😉 Give that red wire +12v im guessing and you got yourself some cool DRL!

    1. @3phase_power – I actually didn’t hook up the DRL. I am not a huge fan of them and I would’ve had to hack up some wiring to get something to work. The van has enough of a hackjob of wiring going on, I don’t need to add to it 😉

  3. Oh wow! Eric, I think you’ve given me my next project for my E450 tow vehicle. Have you tried the 5 star tuning upgrade on your E350 that I did four years back (mine is gas). Long term analysis – I really like it! The mini LED project that I did was to change all of the E450 RV’s interior lights to LED – literally a night and day difference on brightness plus a huge saving on the duration of charge held by the RV cabin batteries. Plus I replaced my outside ‘porch’ light with two LEDs. I put one at the front and one at the back. Now if I need to do some night work on the car, I’ve got superb lighting.

      1. @Frank Ewald Which 5Star upgrade are you referring to? The Van is a weird 7.3 Powerstroke in that the ECU is different than the Ford trucks of the same years and some of the PIDs are different. This is why the Edge programmer (Evolution) version of the Insight wasn’t used — Edge claimed they couldn’t program the van. I do have a much older Edge tuner that came with the Van and I have supposedly programmed it for “towing” (Level 1) mode. I’m not entirely sure how much difference it made because I never really compared it back-to-back.

        As for the interior lights, I am definitely considering upgrading everything to LED. It is quite dark in there.

        As for back-up, well, you’ll have to wait and see! (pun intended)

Leave a Reply

Your email address will not be published. Required fields are marked *