A3 / B4 glow plug relay and fuse location

TonyJetta

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Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
Ok so what is life of the glow plugs?
GP life varies with use. My wife's '06 has 110k miles on the original plugs. But, in southern AZ, coupled with the fact the she gets to drive a garaged car, the GP's don't cycle on very long.

I have 43k miles on the GP's in my '96 and they are still going strong.

Tony
 

idleofwight

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Joined
May 8, 2009
Location
Tigard, OR
TDI
1996 Passat Wagon
I figure in southern az you don't use them at all. So I have 197k it has been north of the mason dixon line for majority of its life. Safe to say they are bad?
 

idleofwight

Veteran Member
Joined
May 8, 2009
Location
Tigard, OR
TDI
1996 Passat Wagon
So pull the harness off the glow plugs, take the plug out? Just put the meter on each end?. I guess I should look at it but it is like-15 out there
 

TonyJetta

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Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
So pull the harness off the glow plugs, take the plug out? Just put the meter on each end?. I guess I should look at it but it is like-15 out there
Not quite...
Pull the harness, then measure the resistance from the glow plug tip to the engine block/cylinder head.

Measure each glow plug. Post your results.

Tony
 

BigJohneyK

Veteran Member
Joined
Mar 7, 2011
Location
minnesota
TDI
I miss my TDI's:(
So I looked through this thread and the first thing that I noticed was that my '98 fuse/relay board looks different. Another guy said the same thing but i don't think my question was answered so be gentle if it was, hahaha. I must have overlooked it.

Here is my board on my '98 Jetta:
http://s1234.photobucket.com/albums/ff413/BigJohneyK/

Question: The relay is still the one numbered 180 right? And the fuse is the huge wired, number 50 right?

P:S: I just need some reasurance that what I am looking at is what it should be. I was being an idiot one night and pulled out a relay and I think I put it back in the same spot but im not sure now that I think about it... Also there is three that are sideways and upside down, does that matter or is that just the plastic shield that doesn't matter how the numbers look?

Thanks guys, It's good to join the forum too!
 
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TonyJetta

Top Post Dawg
Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
Your relay/fuse panel looks like the '98 that's posted at the beginning.

Keep in mind that VW, like others, will make mid year changes. So, the fact that your panel does not exactly match is not too big of an issue. It could be that someone rearranged the relays above the panel, too. You never know.
 

BigJohneyK

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Mar 7, 2011
Location
minnesota
TDI
I miss my TDI's:(
Your relay/fuse panel looks like the '98 that's posted at the beginning.

Keep in mind that VW, like others, will make mid year changes. So, the fact that your panel does not exactly match is not too big of an issue. It could be that someone rearranged the relays above the panel, too. You never know.
ok so everything is where it should be, thats good.

So just to clarify, the relay that is numbered 180 is the glow plug relay right, and the numbered 50 fuse with the huge wires coming out of it is the glow plug fuse right?
 

TonyJetta

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Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
So just to clarify, the relay that is numbered 180 is the glow plug relay right, and the numbered 50 fuse with the huge wires coming out of it is the glow plug fuse right?
Should be...

I've seen a couple different posts. What is your issue? No cold weather start? Long cranking cold start?

You will want to start your own thread...you'll get more specific attention and will be easier to follow YOUR troubleshooting.

Tony
 
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BigJohneyK

Veteran Member
Joined
Mar 7, 2011
Location
minnesota
TDI
I miss my TDI's:(
Should be...

I've seen a couple different posts. What is your issue? No cold weather start? Long cranking cold start?

You will want to start your own thread...you'll get more specific attention and will be easier to follow YOUR troubleshooting.

Tony
K, I am used to vortex where they hunt you down and stone you if you start a thread...:D
 

sewden9

Member
Joined
Apr 10, 2011
Location
Nanaimo, BC, Canada
TDI
97 Jetta GL
I have a 97 Jetta GL.. starting issues are becoming the bane of my poor car. electrical ghosts are no fun. I had cold start issues after working fine all winter. gp's are all fine. mecahnic replaced the gp fuse about 4 weeks ago.. suggested the 136 relay 2 weeks later (which I swapped from a donor car), then the 104 relay was replaced a week later. after intermittent success for a week the new relay began to buzz, like it had a bad connection, and it couldn't decide if it was clicking on or off. I swapped one out of the donor car for a day while I opened it up the one from the mechanic & decided to try it again.. end of the day my battery was dead. swapped the donor 104 back in & it let us jump start last night with some alarm honking. a 5 minute trip around the block was enough to charge it. and this morning it started fine & my original factory casette deck is lighting up everything in it's display- no love lost there. stopping by the mechanic this morning to see if he has a different brand of 104 relay because I do have to give this one back and I'm not so sure about the Kracker one. dad is suggesting I have the battery & alternator tested while I'm there. if this doesn't clear up soon the donor car may become mine so I can swap entire electrical pieces like relay panels.
I like VW's but this doesn't help me drive to work sites all over the city.
 

sewden9

Member
Joined
Apr 10, 2011
Location
Nanaimo, BC, Canada
TDI
97 Jetta GL
yup.. just replaced the fuse/relay panel & it seems to be working consistently now, even the wipers seem to operate more solid. opened up the old box and it's easy to see the corrosion & burn marks on some of the guts. the #12 relay receptical has black marks on the prongs. don't know why it got to that point but will keep in mind for future issues. will post pictures in my photo album on here if anyone wants to see the inside of a fuse panel.
 
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rdkern

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Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
Often times a bad brake switch, or burnt out bulbs. Are your brake lights working? other things as well, but easy stuff first.
 

btcost

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Joined
Aug 13, 2002
Location
Boston, MA
TDI
'12 JSW, '00 Jetta (totaled 12/23/10), 1987 M-B 300D
The light is driven by the ECU. One hopes that the glow plugs are also on through their separate fused circuit, but there is no reason to presume that the cluster illumination is a certain indication of electrical power to any of the glow plugs.

The temperature sender is two units in one housing. One sender drives the gauge in the cluster, the other, the ECU. The ECU half may have failed, but can't be replaced separately.
A constant 20 second duration, regardless of air temperature or engine temperature, indicates that the ECU doesn't know the temperature and defaults to maximum cold values.
Check with VCDS, and check the wiring back to the ECU, too. Twenty seconds indicates an open circuit (bad connection, bad sender, bad wiring).

Jon I'm new to the B4 game as you know.

so what causes this: car appears to start right up, even when cold no real issues. BUT the GP light on the dash only stays on for 1-2 seconds. . . .on my MK4, same outside temp, it would glow for 5-10 sec. . .longer anyway.

hell the 2012 GP light stays on longer when cold. . .

How do you get the dash light to better reflect actual GP time???
 

TonyJetta

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Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
...BUT the GP light on the dash only stays on for 1-2 seconds. . . .on my MK4, same outside temp, it would glow for 5-10 sec. . .longer anyway.
Down to ~40F, mine only comes on for 1-2 seconds. Down to ~30F, mine comes on for ~5 seconds. <30F and it comes on for 5-10 seconds. These are approximate times.

Fundamentally, if the car is starting fine in cold weather, I wouldn't worry too much about the GP light duration.

Feel free to post back any questions or issues.

Tony
 

Lug_Nut

TDIClub Enthusiast, Pre-Forum Veteran Member
Joined
Jun 20, 1998
Location
Sterling, Massachusetts. USA
TDI
idi: 1988 Bolens DGT1700H
Jon I'm new to the B4 game as you know.

so what causes this: car appears to start right up, even when cold no real issues. BUT the GP light on the dash only stays on for 1-2 seconds. . . .on my MK4, same outside temp, it would glow for 5-10 sec. . .longer anyway.
How do you get the dash light to better reflect actual GP time???
Wire it to the glow plug relay instead of the "wait at least this long" ECU output.

1996 wiring using the BK or GQ ECU: Connect a small amperage 12 volt test lamp between fuse S18 and ground. Fuse 18 is powered only when the glow plug contact is closed.

1997 wiring using the FA ECU: No easy test point, sorry :(. Connect a small amperage 12 volt test lamp between the remote mounted glow plug relay terminal 4 or 6 (large gauge, red colored leads) and ground. Be aware that the relay monitors current difference between the two red leads and that a test lead might be enough current difference to trigger a fault.
 

undata

Veteran Member
Joined
Oct 23, 2003
Location
Gaithersburg, MD
TDI
1997 Passat TDI
stupid glow plug fuse - relay

I have owned my 1997 Passat TDI since it was new, and overall it has been a positive experience.
The strange thing about VW, some parts of the car I look at, and say "how smart is that?" There are other features that make you exclaim "How stupid is that?"

I have sighted the glow plug relay, thanks to the pictures. It is probably possible to reach it, but scary because replacing it might be very difficult. The fuse I have no idea - it's just a maze of wires above the main fuse block. The Japanese would never do something like this...
 

undata

Veteran Member
Joined
Oct 23, 2003
Location
Gaithersburg, MD
TDI
1997 Passat TDI
Down to ~40F, mine only comes on for 1-2 seconds. Down to ~30F, mine comes on for ~5 seconds. <30F and it comes on for 5-10 seconds. These are approximate times.

Fundamentally, if the car is starting fine in cold weather, I wouldn't worry too much about the GP light duration.

Feel free to post back any questions or issues.

Tony
It (yellow lamp) works on a timer and thermometer on my B4 Passat. It is not actually connected with the glow plug circuit.
 

TonyJetta

Top Post Dawg
Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
It (yellow lamp) works on a timer and thermometer on my B4 Passat. It is not actually connected with the glow plug circuit.
The ECU controls the yellow lamp, based on temperature and time for pre-glow. Although, even when the lamp turns off, the GP's are on.

Basically, the ECU is telling you to wait, based on the assumption the GP's are working and are heating up to assist in starting a cold diesel, by providing a heat source in the combustion chamber.

After starting, the GP's stay on until the coolant temp is >~70F, IIRC, but the GP light is off.

Even when the GP's aren't needed for starting, they will come on, until the coolant temp is warm enough.

Tony
 

undata

Veteran Member
Joined
Oct 23, 2003
Location
Gaithersburg, MD
TDI
1997 Passat TDI
Help please

I have just replaced the 180 gp relay on my B4. After much shivering and cursing, outside in the winter. I had to yank and wiggle and it finally came down still plugged in, where I could replace it.
NOW HOW DO I REPLACE THE FUSE? It's up behind the fuses and the rat's nest behind it, hard against the firewall. It has a black plastic tab pointing against me. I would have to pull that tab towards me, while pulling the fuse out with some combination of my remaining fingers on the one arm. All by feel, can only get one arm in there, with my cheek against the dashboard, so I can't see what I'm doing. Suggestions?

Update it is an 80A (32V) fuse.
 
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TonyJetta

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Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
Remove the knee bar; an Allen socket and a #3 Phillips. That should gain you enough access. Actually, short of removing the entire dash, that's about all your are going to get!

Tony
 

Mcgink

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Joined
Oct 15, 2004
Location
South of Boston MA
TDI
I-Red,"The Passat formerly known as Harlequin" 97 B4, a non VW GTDI too
I have just replaced the 180 gp relay on my B4. After much shivering and cursing, outside in the winter. I had to yank and wiggle and it finally came down still plugged in, where I could replace it.
NOW HOW DO I REPLACE THE FUSE? It's up behind the fuses and the rat's nest behind it, hard against the firewall. It has a black plastic tab pointing against me. I would have to pull that tab towards me, while pulling the fuse out with some combination of my remaining fingers on the one arm. All by feel, can only get one arm in there, with my cheek against the dashboard, so I can't see what I'm doing. Suggestions?

Update it is an 80A (32V) fuse.
Check post# 95-98 in this sticky to make sure you don't have this issue that I had on my wagon. If you unlatch the fuse/relay panel and lower it down, you can acces that fuse against the firewall (behind/above the ratsnest of wires) to the left of the clutch If I recall. It does still require the dexterity of a contortionist though.
 
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