'02 Glow plug harness replacement (56k warning!)
- Thread starter tdi_allan
- Start date
MOGolf
Top Post Dawg
- Joined
- Jun 27, 2001
- Location
- underneath something
- TDI
- 2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
Did you clear the fault code?
kasper
Veteran Member
I attemped to do the GP harness change on my 02; everything went straightforward as per the above writeup but... surprise surprise, when I got to the actual plug in the " secret" place, I found that the connector on my new 4 wire harness from TDI parts has 4 "male " prongs on it and the old one has 4 "female" ones. ***? The plugs appear the same on the outside and they are a molded part. Is there another 4 wire harness out there or have I missed something?
The old harness plug has a part # 1JO 973 724 , the new one is 1JO 973 824.
Ted
The old harness plug has a part # 1JO 973 724 , the new one is 1JO 973 824.
Ted
MOGolf
Top Post Dawg
- Joined
- Jun 27, 2001
- Location
- underneath something
- TDI
- 2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
Look at the other connector at that "secret" location. You'll see that '824' mates to '724'.
kasper
Veteran Member
Thanks Mogolf.
After putting the car back together, I pondered the dilemma and was obviously fooled by the routing of the harness. I didn't bother to take the wrapping off the harness , hoping to do the "ghetto' method.
It was just that the wiring coming up from the bottom seemed to be the wiring from the glow plug harness and I didn't want to do any cutting until I was sure. So as I later suspected, the harness coming down from above is the actual glow plug harness and from below comes from the relay.
Again thanks for the info, it confirms again the value of this forum. If I had done a continuity check, I would have cleared up the wiring question.
Better to think twice before cutting.
cheers
Ted
After putting the car back together, I pondered the dilemma and was obviously fooled by the routing of the harness. I didn't bother to take the wrapping off the harness , hoping to do the "ghetto' method.
It was just that the wiring coming up from the bottom seemed to be the wiring from the glow plug harness and I didn't want to do any cutting until I was sure. So as I later suspected, the harness coming down from above is the actual glow plug harness and from below comes from the relay.
Again thanks for the info, it confirms again the value of this forum. If I had done a continuity check, I would have cleared up the wiring question.
Better to think twice before cutting.
cheers
Ted
flyingcat
Active member
If one chooses to do the "getto" method to save time, must one remove the air box and battery box to gain access to the "secret plug"?
Would it help to use diaelectric grease i.e. CAGE mod inside the connectors to keep corrosion to a minimum??
I just recieved the new assy from TDI Parts yesterday. Can't wait to get started!!
Any suggestions will be greatly appreciated.....
Would it help to use diaelectric grease i.e. CAGE mod inside the connectors to keep corrosion to a minimum??
I just recieved the new assy from TDI Parts yesterday. Can't wait to get started!!
Any suggestions will be greatly appreciated.....
Sappington
Veteran Member
You do not have to remove the battery box, but you do have to remove the air box. You don't have to take the accordion hose off the air box, but it does make life easier if you do.
flyingcat
Active member
One project off the list! No more glow plug CEL for some time now!
MAny thanks for all the great support from this site!
MAny thanks for all the great support from this site!
manfish
Well-known member
No replies on this thread for quite a while... I replaced my GP harness today as per the instructions on this thread. Man I love the TDIclub forums!
AutobahnTDI
Veteran Member
Where would one buy the "rubber amalgamating tape" to wrap the wires?
MOGolf
Top Post Dawg
- Joined
- Jun 27, 2001
- Location
- underneath something
- TDI
- 2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
I use friction tape available at electrical supply locations in hardware stores, etc.
truav8r
Veteran Member
Bringing this thread back to life... got a CEL, indicating bad #2 GP, but all of my GPs tested at 1.1ohms. Relay checkout out too. So... time to replace harness.
Question... any reason why I couldn't also use the dielectric compound on the harness sockets for each individual GP?? Wouldn't that help to keep the connection at each GP dirt- and moisture-free??
Question... any reason why I couldn't also use the dielectric compound on the harness sockets for each individual GP?? Wouldn't that help to keep the connection at each GP dirt- and moisture-free??
Jeff Heyerman
Veteran Member
Did mine today per the first post (6 feet of harness unwrapping and re-wrapping). Nothing complicated, but quite a bit of work. All told probably 4-5 hours. Finally driving around w/o a CEL! Woohoo!
Many will probably laugh at me, but I bought the cloth electrical tape from the VW dealer. Nice stuff to work with and visually you can't even tell I replaced the harness.
Jeff
Many will probably laugh at me, but I bought the cloth electrical tape from the VW dealer. Nice stuff to work with and visually you can't even tell I replaced the harness.
Jeff
JettaDan
Well-known member
Glade to see the 4 wire harness replacement because my 03' Jetta with under 137,000 miles has started to throw a code showing glow plug number 4 bad. Everything checks out so it must be the harness. Now I know how to do the change before the cold weather sets in. Have put it off for the past three months.
By the way, I have prevented the "check engine" light by doing the old double glow plug warm-up rout before starting the engine. I have not tried the Deoxit D5 cleaner but, may give it a try before I receive the new harness.
By the way, I have prevented the "check engine" light by doing the old double glow plug warm-up rout before starting the engine. I have not tried the Deoxit D5 cleaner but, may give it a try before I receive the new harness.
1854sailor
Resident Curmudgeon
Using Deoxit cleaner AND shield is definitely the way to go. It has solved many electrical demons for me over the years.
http://forums.tdiclub.com/showthread.php?t=291951
ymz
Top Post Dawg
- Joined
- May 12, 2003
- Location
- Between Toronto & Montreal
- TDI
- 2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
$100 ??? Metal Man has your model harness for $55 shipped...
Still, you saved a bunch...
Y.
Still, you saved a bunch...
Y.
Check engine light didn't extinguish
Thanks for the info. It was very helpful in replacing the 4 wire harness.
Is there something else I need to do to clear the check engine light or should it have extinguished automatically?
Thanks for the info. It was very helpful in replacing the 4 wire harness.
Is there something else I need to do to clear the check engine light or should it have extinguished automatically?
Bran Diezel
Veteran Member
plug in any obdii scanner and delete the code. or have an autoparts store clear it if you don't have any software.
marshalldanielp
Veteran Member
Great write up. I replaced mine yesterday and ran the harness seperately to make future service easier. Reset the mil and has stayed off. Thanks for posting or I would have done the snip and splice. Thanks again.
Dan
Dan
RockvaleTN-TDI
Active member
What code(s) were you getting that caused the CEL? Did replacing the harness fix the problem?
marshalldanielp
Veteran Member
I was getting the P0674 code mostly, however I did recieve a code from ever plug at one time or another. Replacing my harness did clear the code, but I pretty much knew it needed to be replaced due to visible damage, it was cracked and one of the interior parts would pop off and remain on the plug. I had also ohmed out the plugs ect.
I would recomend that you read the post titled glow plugs 101 version 2.0. before you proceed. http://forums.tdiclub.com/showthread.php?p=749854
The post provides information on troubleshooting the glow plug system. Beacause it could be multiple issues plug, harness, relay. Instead of throwing parts at the car that migth not fix the issue. The harness and new plugs are around $100. I would want to be sure before buying a new harness. And if you do get a new harness, get the one with the plug and do it right no snip and crimp job for peace of mind.
Dan
I would recomend that you read the post titled glow plugs 101 version 2.0. before you proceed. http://forums.tdiclub.com/showthread.php?p=749854
The post provides information on troubleshooting the glow plug system. Beacause it could be multiple issues plug, harness, relay. Instead of throwing parts at the car that migth not fix the issue. The harness and new plugs are around $100. I would want to be sure before buying a new harness. And if you do get a new harness, get the one with the plug and do it right no snip and crimp job for peace of mind.
Dan
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FYI, there's no plug w/BEW harnesses. You'll have to solder or crimp.
MarkO-Indy2
Member
I have the CEL for the GP....I have had the 2002 Beetle for 4+ years,...I had noticed that the GP harness had been replaced when I bought the car, what I didn't notice until the CEL popped on, is the harness on mine is a 2-wire harness....whoever did the work did the snip "ghetto" method......to a 4-wire harness, still wrapped with the other wires. That has me scrtaching my head at the moment. I need to change the oil & filter this week, so I will get into it and see what they did under the air box at that connection.
Has anyone every heard of this?
Mark
Has anyone every heard of this?
Mark
Gil
Veteran Member
After all the very nice instructions posted here, has anyone taken the time to cut away the heat hardened rubber and found the connections to the glow plugs rather loose ?
IMHO, this condition is the main reason for our CEL problems.
I found this information somewhere here and thought I would give it a try BEFORE I replaced the harness, glad I did.
IMHO, this condition is the main reason for our CEL problems.
I found this information somewhere here and thought I would give it a try BEFORE I replaced the harness, glad I did.
sc00byd00311
Veteran Member
damn it! I had to buy the one engine that doesn't have a freaking connector!?!? Has anyone added their own in? I might look at that.
dtvenus
New member
Cold start issue due to unexplained relay problem
Hi, Can anyone help with a cold start up issue. Having followed guidance in this forum, I have now got this far.
Our Seat Leon TDI continues to be difficult to start with the usual symptoms of repeated starts and eventual fire up with smoke emitted from the exhaust.
I have recently replaced all four glow plugs, having found two to be faulty. I also replaced the relay. It had a yellowish deposit coming out near the two smaller central blades.
With a new relay I have tested the voltage at the harness connections with the engine cold, and found no voltage. I checked various possibilities, and finally decided to check the new relay. I did this with a multitester as before, but this time from the inside of the car where the relay plugs into the board.
I found the relay was switching, but not producing any voltage on the output blade. I double checked there was no voltage at the harness connectors. I then decided to check the output once the engine started, and found the voltage to immediately appear on the output blade. Again I double checked the output at each harness connector, and found the voltage appear when the engine fired up, and not switch off until the engine was switched off !
It appears that the relay is switching, but in reverse. Clearly voltage at the glow plugs after the engine has started is not required, and if I ran the car with the harness connected, would probably burn the glow plugs out before too long. It also explains why I am getting poor starting because the glow plugs are not receiving any voltage before starting up.
I have tried a new relay in case there was an error with the first replacement, and exactly the same thing happens.
A bit of history which may be relevant. The ignition barrel was replaced some years ago, and I am wondering, is it possible this has been wired up incorrectly. The car has been a difficult starter over this period...non operative relay and two duff glow plugs obviously not helpful.
Any help much appreciated.
Hi, Can anyone help with a cold start up issue. Having followed guidance in this forum, I have now got this far.
Our Seat Leon TDI continues to be difficult to start with the usual symptoms of repeated starts and eventual fire up with smoke emitted from the exhaust.
I have recently replaced all four glow plugs, having found two to be faulty. I also replaced the relay. It had a yellowish deposit coming out near the two smaller central blades.
With a new relay I have tested the voltage at the harness connections with the engine cold, and found no voltage. I checked various possibilities, and finally decided to check the new relay. I did this with a multitester as before, but this time from the inside of the car where the relay plugs into the board.
I found the relay was switching, but not producing any voltage on the output blade. I double checked there was no voltage at the harness connectors. I then decided to check the output once the engine started, and found the voltage to immediately appear on the output blade. Again I double checked the output at each harness connector, and found the voltage appear when the engine fired up, and not switch off until the engine was switched off !
It appears that the relay is switching, but in reverse. Clearly voltage at the glow plugs after the engine has started is not required, and if I ran the car with the harness connected, would probably burn the glow plugs out before too long. It also explains why I am getting poor starting because the glow plugs are not receiving any voltage before starting up.
I have tried a new relay in case there was an error with the first replacement, and exactly the same thing happens.
A bit of history which may be relevant. The ignition barrel was replaced some years ago, and I am wondering, is it possible this has been wired up incorrectly. The car has been a difficult starter over this period...non operative relay and two duff glow plugs obviously not helpful.
Any help much appreciated.
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FiremanBob
Active member
Not to commit thread necrophilia, but I followed the OP to replace the harness in my 03, and the job went just fine thanks to the excellent instructions and photos. I did not unwrap the harness, but put the new harness into a plastic conduit from the parts store and ran it alongside.
As a bonus: Taking out the airbox revealed a totally choked air filter. With the new filter there was an obvious improvement in performance - yes, it was that bad.
Thank you for creating this valuable thread.
As a bonus: Taking out the airbox revealed a totally choked air filter. With the new filter there was an obvious improvement in performance - yes, it was that bad.
Thank you for creating this valuable thread.