matrick
Member
On the last Friday of 2017, I bought an '04 Passat TDI with a check engine light (go figure) for an open glow plug circuit. About two months later, I decided to actually look into it and get rid of the engine light. When I went to Ohm out the glow plugs, I noticed that most of the boots on the wires were torn up real bad (as you can see below), so I committed to replacing all four wires (the issue was actually cylinder 4 glow plug, which I just replaced today).
I started by buying four glow plug wires from ECS found here (part number is 028 971 782 A, in case the link is dead in the future).
Here they are:
and here's one up close:
It's a pretty simple process. You just need to cut out the old wires and either solder or use crimp connectors to insert these into the circuit. I chose to solder because it's a much more stable connection than a crimp connection. (I honestly do not recommend using crimp connectors at all, just saying it's an option)
Tools Needed:
Soldering Iron
Solder (preferably electrical rosin-core)
Wire Cutters/Dikes
Exacto Knife/Boxcutters (to cut back the wire covers)
Electrical Tape (liquid or just tape) or Heat-shrink Tubing
Wire Strippers
(Optional) Needlenose Pliers (they help to remove the boots without destroying them)
I ended up using heatshrink tubing even though it's not in the picture and liquid electrical tape is. Also, my multimeter is there just because I decided to ohm out my glow plugs at this point, since I'm taking all the wires off anyway.
As far as the actual process goes, it's just basic soldering one wire onto another wire, just cut the male terminal ends off of the new wires and solder it all up. I prefer using the method of splicing where you stick the frayed ends of each wire into one other so that the strands all meld together then you just twist it tight. I find it much easier to get a good seal with the heatshrink tubing using this method. Here are a few pictures of each stage in the process. One tip I have is to do one wire at a time that way you don't mix any of them up.
Wires twisted together:
Wires soldered (make sure to get good wicking and penetration of the solder):
The finished product:
A few notes:
I spent a lot of time looking for some sort of connector close to the glow plugs since these wires come with a male terminal end and I couldn't find one. After pulling a diagram, I discovered that there's supposed to be an Automatic Glow Time Control Module right underneath the cylinder 4 glow plug that they all connect in to, but as you can see in this thread TDIs don't have an AGTCM, so I guess the diagram was wrong. If you know of a way to install new glow plug wires using the actual terminal end that they come with, then please let me know.
You may find that the fuel filter gets in the way a little bit especially when dealing with the cylinder 4 wire. If you follow the removal steps in this thread, you can pull the filter out of its bracket and get it into a less intrusive location without removing any of the hoses from it, as shown below.
When I was initially searching for any guides on how to replace the wires, I stumbled across this article. It seems like it may work pretty well. If I ever have to do my wires again, I may try this out. In which case, I'll update this post with my results. Feel free to try it out on your own and let me know how it works for you.
I started by buying four glow plug wires from ECS found here (part number is 028 971 782 A, in case the link is dead in the future).
Here they are:
and here's one up close:
It's a pretty simple process. You just need to cut out the old wires and either solder or use crimp connectors to insert these into the circuit. I chose to solder because it's a much more stable connection than a crimp connection. (I honestly do not recommend using crimp connectors at all, just saying it's an option)
Tools Needed:
Soldering Iron
Solder (preferably electrical rosin-core)
Wire Cutters/Dikes
Exacto Knife/Boxcutters (to cut back the wire covers)
Electrical Tape (liquid or just tape) or Heat-shrink Tubing
Wire Strippers
(Optional) Needlenose Pliers (they help to remove the boots without destroying them)
I ended up using heatshrink tubing even though it's not in the picture and liquid electrical tape is. Also, my multimeter is there just because I decided to ohm out my glow plugs at this point, since I'm taking all the wires off anyway.
As far as the actual process goes, it's just basic soldering one wire onto another wire, just cut the male terminal ends off of the new wires and solder it all up. I prefer using the method of splicing where you stick the frayed ends of each wire into one other so that the strands all meld together then you just twist it tight. I find it much easier to get a good seal with the heatshrink tubing using this method. Here are a few pictures of each stage in the process. One tip I have is to do one wire at a time that way you don't mix any of them up.
Wires twisted together:
Wires soldered (make sure to get good wicking and penetration of the solder):
The finished product:
A few notes:
I spent a lot of time looking for some sort of connector close to the glow plugs since these wires come with a male terminal end and I couldn't find one. After pulling a diagram, I discovered that there's supposed to be an Automatic Glow Time Control Module right underneath the cylinder 4 glow plug that they all connect in to, but as you can see in this thread TDIs don't have an AGTCM, so I guess the diagram was wrong. If you know of a way to install new glow plug wires using the actual terminal end that they come with, then please let me know.
You may find that the fuel filter gets in the way a little bit especially when dealing with the cylinder 4 wire. If you follow the removal steps in this thread, you can pull the filter out of its bracket and get it into a less intrusive location without removing any of the hoses from it, as shown below.
When I was initially searching for any guides on how to replace the wires, I stumbled across this article. It seems like it may work pretty well. If I ever have to do my wires again, I may try this out. In which case, I'll update this post with my results. Feel free to try it out on your own and let me know how it works for you.