Glow Plug Harness: Powerstroke Parts on a VW TDI

I’ve been enjoying my 2005 Passat Wagon TDI for nearly two years, now. Like my Jetta, it’s another little diesel in my fleet. The engine is the BHW code, making it a Pumpe Duse engine. It’s not as efficient as the Jetta’s ALH engine, but it still gets me into upper 30s, but with a more comfortable family machine with a leather interior. When I bought the car it had a dead automatic transmission, so I was able to get a deal on it. I dragged it home and got to work on swapping the transmission for a standard using used factory parts sourced from Dutch Auto Parts in the Netherlands. Today you wouldn’t know that it came with an automatic transmission in it, because it looks completely stock.

This is the inexpensive part I used to replace my worn-out glow plug harness on my Passat TDI.

This is the inexpensive part I used to replace my worn-out glow plug harness on my Passat TDI.

The car now has 200,000 miles on it and I started getting the dreaded “EMISSIONS WORKSHOP” messages every time I started the engine. Pulling the codes, I found out that I had an open circuit at one of my glow plugs. I checked the glow plug and found that it had good continuity, so I knew it was the harness. VW charges too much for glow plug harnesses, and I must say that I didn’t bother to price it this time around. I wrote up an article a while back showing how to use R/C bullet connectors to make a glow plug harness rather than spending $80 on a factory part. Some of you told me that you’ve used the Powerstroke 6.0 harnesses you’ve bought on eBay, so I decided to give this a try. I found this one on eBay for $19.99. In case that link is dead, the seller was calvinvo, and the title was “2004 – 2010 Ford 6.0L Powerstroke Diesel Glow Plug Harness Left Driver Side.”

It came fairly quickly after I ordered it. I got started by chopping off the connector and peeling back the convoluted tubing. THEN, I realized that I’d like to start blogging again and took a snapshot of it. I should have taken a snapshot first, but this still gives you an idea of what it looked like.

I checked the four wires with an ohmmeter to see which color went to which connector. Using the one closest to where the connector used to be for the #1 cylinder, the codes are yellow for #1, red for #2, white for #3, and blue for #4. I tried snapping one of them onto the #1 glow plug after I removed the original harness, seeing that the large plastic caps would allow the couplers to snap onto the glow plugs.

Note that the black coolant tube has dimples near the glow plugs to make room for the stock harness.

Note that the black coolant tube has dimples near the glow plugs to make room for the stock harness.

I made new solder connections and covered them in heat-shrink tubing. Then, I went to install the harness and found that #3 and #4 didn’t fit. I realized that a coolant tube runs quite close to the head on the BHW engine, keeping the large plastic connectors from sliding into place. To make room for the stock harness, I noticed that VW put dimples in this tube.  I wasn’t going to enlarge the dimples or relocate the tube, so I got out my rotary tool and used a cutting disk to remove material from the underside of the plastic connectors for glow plugs #3 and #4.

These plastic connectors have o-rings for the Powerstroke application that must be used to keep water from getting into the cavities where the glow plugs are on that engine. The VW TDI engines have glow plugs that are exposed to the air, so there’s no need for this much plastic. I trimmed them back until I could snap the connectors in place.

I trimmed the glow plug connectors on cylinders #1 and #2 so that they would fit alongside the coolant tube that runs past the BHW head.

I trimmed the glow plug connectors on cylinders #1 and #2 so that they would fit alongside the coolant tube that runs past the BHW head.

Success! I’ve been able to clear the code and I no longer create an embarrassing blue haze hanging in the air when I start the cold engine on a cold day!

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Comments (3)

  1. Mark-A-Billy

    By the way, everybody, the cheap Powerstroke harness I had didn’t hold a very good crimp and I wound up with open circuits a couple times. Trying to put a little crimp on these just made things worse. I wound up using 4mm bullet connectors from model airplane supplies and some wire.

    • Andy Cardwell

      I have no idea how many have found this useful but, I know I have! Thank you so much for your very helpful information complete with illustrations.

      P.S. On a completely unrelated note, I also am an independent thinking, Catholic with Libertarian ideals who also happens to love the greater power and efficiency of diesel engines. I used to have a few Jettas with the ALH engine and am currently working on a 2005 Passat BHW TDI wagon that I also bought with a bad transmission. Hearing all of the nightmare stories about the balance shaft chain/oil pump drive problems with these cars, I pulled the engine out with the transmission attached in order to do both things at once. Which is why I had to remove the engine wiring harness and when I did, the glow plugs connectors just crumbled in my hand exposing the bare copper. Even though I paid almost $60 for my powerstroke harness, it was still a significant discount over the VW parts. Thank you sir!

      • Mark-A-Billy

        Thanks, bioenergy74! Sounds like we have a lot in common!

        My TDIs are gone, now. If I go back it’ll definitely be to the ALH because I was much more impressed by that engine’s tunability, torque, and efficiency than the lackluster experience I had with the BHW. Perhaps an ALH with significant upgrades would be a good transplant in an old Jeep or other small 4×4 later on.

        What killed the wagon for me was the second time that synchro went out in two years. One problem with used transmissions sourced from overseas is that you don’t really know anything about the car that they came out of, not even the mileage (they’ll claim a mileage, but you have no way to confirm it, really), and nobody in the USA will rebuild those manual transmissions. If I’d been more impressed with the machine, I’d order another manual and get somebody in Europe to rebuild it so that I could get a few hundred thousand miles out of it before I need to mess with it again.

        I now have a fleet of five vehicles, but I only have two drivetrains. Three Corollas (kids drive two, I drive one daily) and two Mercedes with the OM642 diesel powerplant coupled to identical transmissions and transfer cases. One is an R320 CDI (415 lb-ft Malone tune in a 5,000 lb AWD minivan that gets 30 mpg on the highway), and the other is my wife’s ML320 CDI (440 lb-ft Green Diesel tune that really pulls hard even in a 5,000 lb vehicle and mid-20s fuel economy). The Toyotas are boring vehicles that get us from A to B with no fuss. The Mercedes, vehicles, however, are really nice, fun to drive, and I got them for cheap.

        Hopefully in the future I’ll dig out the footage of work I’ve done on both of these and make some how-to videos. I’ve just been up to my neck in trying to make a career change.

        Thanks for your message!

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