Top Post Dawg
- Sep 15, 2005
- Tucson, Az
- '15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
So...was it that 2nd relay?
THe solenoid for the fresh air / recirculate change is on the left inner fender / mud guard of the B4 Passat. I don't know where it might be on the Cordoba. Locate the fresh air intake at the base of the windscreen under the hood / bonnet. Look for a small (4 or 5 mm?) air hose that goes to that area. Follow that hose to its other end.So where is that selonoid valve located at? What is the item number do you know?
Where exactly does the heavy gauge positive feed for this GP fuse come from? Where in the CE2 fuse box? TDI swapped mk2 and I totally just realized there was a heavy gauge red wire coming out of this fuse holder and I never hooked it up. This would explain my nightmare cold starts. I believe it's like a 4 or 6 gauge wire with a yellow(?) connector?!
It's in this thread somewhere, but it's an obsolete part. You can make one or repair the one you have.Anyone know the P/N for the jumper relay used with the FA wiring?
It's fixed, I took the part from relay position #12 from my B4 sedan and compared it to the 103 relay which was in my B4V.
This is what they look like opened up:
I'm thinking that at some point that the PO had a cold start issue and a Tech replaced the wrong part. The part on the right is callled a "Bridge" and the part # is: 3A0 941 817. FYI the part is obsolete according to the local VW dealer's parts dept.
Without the info/pics in the begining of this thread, I would no doubt be still scratching my head trying to diagnose the root cause of my cold start issue.
Thank youThe question of which fuse or relay is the one for the glow plugs won't go away. Perhaps this one thread will eliminate the 40 or 50 each year that ask the same question over and over.
The fuse for the four cylinder glow plugs is located inside the cabin above the fuse and relay mounting block. Please see the images below for the locations on the B4 Passat (near the top of the inside firewall), and on the A3 Jetta (at the top of the fuse and relay block).
On the North American market 1996 Passat the glow plug relay is the one in position #12 of the fuse and relay block just above the driver's feet. The relay is identified by a "103" printed on its top. Note: The Bentley manual electrical schematic has a typo which indicates this glow plug relay is marked with "104". The image below shows a typical 1996 B4 relay layout. The glow plug fuse location is similar to that shown in the 1997 B4 image to follow.
This wiring harness requires the BK or GQ ECU.
On the North American market 1997 Passat the glow plug relay is moved to a remote location above the main fuse and relay block. There were several other wiring changes made at this transition. The glow plugs relays are not interchangeable between the early and the late wiring harness changes. The glow plug relay is now marked "180". A 'jumper relay' is installed in position #12 to allow electrical power to feed to the remote 180 glow plug relay location. The other relays in the relay and fuse block are positioned similar to those shown in the previous 1996 image. The image below shows the mounting location of the "180" glow plug relay in the 1997 and also the glow plug fuse location in both the 1996 and 1997 B4. Thanks to TonyJetta for the edit of PaulB's picture showing the 1997 relay and fuse location.
This wiring harness requires the FA ECU.
Important Note: The wiring harness change in the B4 TDI took place part way through the 1997 model year. According to the Bentley manual the change over took place at the end of October 1996 for the last of the early, BK/GQ/103 wiring harness, with a November 1996 start for the later, FA/180 wiring harness. Very early 1997 models, those built in June through October of 1996, might therefore have a harness similar to the 1996 models and would require the "103" relay.
The glow plug relays are not interchangeable between harnesses. The relays and/or the wiring harnesses can be damaged, and wiring harness fire inside the cabin is a real possibility, due to the dead shorts created by improper glow plug relay use.
The North American market 1998 A3 has the "180" glow plug relay attached above the main relay block. The glow plug fuse is mounted just above the glow plug relay, not separately on the inner firewall as on the B4. Also note in the image below that there is nothing in the lower right relay socket (location #12). This is a difference from the 97 B4 TDI which needs a jumper to feed power to the glow relay 180.
Note: The installation of a #12 jumper relay from a 1997 B4, or the installation of a "103" or "180" glow plug relay in this vacant position with the 1998 A3 wiring harness can also cause damage to electrical components and possibly fire from dead shorts.
Note: The Bentley wiring schematics show a change in the wiring of the glow plug relay during the A3 TDI production years. I have no further knowledge of the differences than what is described below in post #7.
In the 98 A3 the socket #12 is empty. The glow plug fuse is before the glow plug relay. The fuse is always hot. Again there is no easily accessed test point for either.
Note that the Bentley A3 service manual's electric schematic, sheet 97-415, indicates the glow plug wires from the glow relay are 0.5 mm in cross section. The correct size is 5.0 mm cross section.
Ok thanks I'll go check them out. Do you know which one would be my glow plug relay?The relay marked with the production code 53 is an ordinary, run-of-the-mill relay such as would be used for the horn or fog lamps or any of a number of functions, but not for the glow plugs.
All those fuse and relay modules above the main array can be moved around, taking their wires with them so the arrangement map varies whether it was Johann or Juan building that car.
I don't have a Bosch cross reference but the fat red wire going away is another clue that the 53 relay isn't involved with that fuse holder.
Most auto part stores will have the high current blade fuses. I know the AutoZone near my house does.
Sorry for the delay in response, but yes. Pulled the errant relay & all issues went away, magically.So...was it that 2nd relay?
The ECU designation depends solely on the chips installed.
Your computer might say "Windows" on the outside but load Linux and it's not a windows machine anymore, is it?
Take an ECU with a "JB" sticker on the outside of it, remove the JB program chips, install the FA chips and it's an FA ECU no matter what the sticker reads.
The odd one is the "BK" ECU as the circuit boards have completely different configuration and the other A3/B4 ECU chips won't even plug in.
The North American market harness / case / chip compatibility is shown below
wiring harness----------------ECU case ID-----------chip ID
1996 B4---------------------BK (black plastic)--------BK
1996 B4---------------------ED, FA, GQ, JB----------GQ
1997 B4---------------------ED, FA, GQ, JB----------FA
1997~1999 A3---------------ED, FA, GQ, JB----------ED, JB
You should have no relay in position 12, that needs to come out of there. By mid-late 1997 production position 12 had been abandoned for GP relays, the large 180 relay above the fuse box and the maxi fuse replaced this whole setup.my 98 jetta does not look like the '1998 A3' pic on the first page. the relay is in the same position as the '180' pictured, and has the 50A fuse at the top, but is missing the '180' markings (perhaps it was replaced). i also have a '175' marked relay inthe lower right cornar (for something else? ive seen some pics with the glow plug relay in the lower right corner there
Unlikely that they would test good but be bad. Did you read the post before yours where he talks about the maxi-fuse being burned out? I would check that.Has anyone ran a main line from fuse area on glow plug to glow plugs on 1997 tdi seem to be having issues with glow plugs and tested all of them and seem good. Is there anyway they could test good and still be bad?