Author |
Message |
finefleisch Samba Member
Joined: April 11, 2019 Posts: 11 Location: NC
|
Posted: Fri May 03, 2019 3:36 pm Post subject: Vanagon Relay box/ electrical issue |
|
|
I have a 1985 VW 1.9L watercooled and i think the relay box/electrical is all jacked up was looking for some help. the red wire in the photo is acting as a ground is this correct? the black and while stripe wire is hot when i turn the ignition on and the white wires lead the the fuel pump/injectors and stuff but i cant get these relays to work i bought new ones and put them in and nothing i know the fuel pump works when i jump the hot connection from 85 to 87 but i cant get any power at the injectors and im thinking this is the issue and ideas?
|
|
Back to top |
|
|
Ahwahnee Samba Member
Joined: June 05, 2010 Posts: 9776 Location: Mt Lemmon, AZ
|
Posted: Fri May 03, 2019 4:28 pm Post subject: Re: Vanagon Relay box/ electrical issue |
|
|
Do you have the wiring diagram (Bentley)?
In case the answer is no, this may help:
|
|
Back to top |
|
|
crazyvwvanman Samba Member
Joined: January 28, 2008 Posts: 9895 Location: Orbiting San Diego
|
Posted: Fri May 03, 2019 6:31 pm Post subject: Re: Vanagon Relay box/ electrical issue |
|
|
The red wire is battery power! It should be hot 100% of the time. Inside the black wiring box there is a power stud where red power wires join, including that one. Make sure that stud has 12v and fix things if it doesn't. Let us know.
In your year a typical cause of no battery power at the red wire post is a problem at the starter motor wiring. Commonly someone changes the starter or does a clutch job and misses hooking up one of the wires on the starter.
Mark |
|
Back to top |
|
|
Steve M. Samba Member
Joined: July 30, 2013 Posts: 6798 Location: Fort Lauderdale, Fl.
|
Posted: Sat May 04, 2019 4:39 am Post subject: Re: Vanagon Relay box/ electrical issue |
|
|
Just an FYI if you do not already know it. The solid brown wires are the ground wires on the Vanagon. _________________ This free advice is worth exactly what you paid for it.
There are seven days in a week. Someday is not one of them. |
|
Back to top |
|
|
sanchius Samba Member
Joined: May 03, 2007 Posts: 1446 Location: IN
|
Posted: Sat May 04, 2019 6:49 am Post subject: Re: Vanagon Relay box/ electrical issue |
|
|
Steve M. wrote: |
Just an FYI if you do not already know it. The solid brown wires are the ground wires on the Vanagon. |
We should add "Brown is ground" to the "Change your fuel lines!" chant for new owners.
I must admit that I'm having a hard time visualizing the operation of the Fuel Pump Relay wiring shown in the diagram above.
Where is the ground? Is White20 serving as a switched ground to the FPR 86 terminal? _________________ The Syncro years (2005-16) - The 2WD years (2017-23) - Westy & WBX rebuild spreadsheet - Sanchius & Tuna: The Video
Your gold star membership keeps this awesome list going! |
|
Back to top |
|
|
Ahwahnee Samba Member
Joined: June 05, 2010 Posts: 9776 Location: Mt Lemmon, AZ
|
Posted: Sat May 04, 2019 6:57 am Post subject: Re: Vanagon Relay box/ electrical issue |
|
|
Of course terminal 30 86 is the ground on a Bosch relay but it appears in this case (fuel pump) that is controlled by the ECU, thus not a brown wire.
Last edited by Ahwahnee on Sat May 04, 2019 1:38 pm; edited 1 time in total |
|
Back to top |
|
|
crazyvwvanman Samba Member
Joined: January 28, 2008 Posts: 9895 Location: Orbiting San Diego
|
Posted: Sat May 04, 2019 7:01 am Post subject: Re: Vanagon Relay box/ electrical issue |
|
|
In this case the ground for the pump relay is a white wire that comes from the ECU. Inside the ECU is an electronic switch that connects ground to the white wire when the ECU thinks the fuel pump should run.
This is also how the fuel injectors work. They have power all the time when the key is on but they only fire when they get a ground from the ECU, and the longer the ground lasts the more fuel they inject.
Normally pin 30 of a relay is battery power and that is the case here also.
Mark
sanchius wrote: |
Steve M. wrote: |
Just an FYI if you do not already know it. The solid brown wires are the ground wires on the Vanagon. |
We should add "Brown is ground" to the "Change your fuel lines!" chant for new owners.
I must admit that I'm having a hard time visualizing the operation of the Fuel Pump Relay wiring shown in the diagram above.
Where is the ground? Is White20 serving as a switched ground to the FPR 86 terminal? |
|
|
Back to top |
|
|
MarkWard Samba Member
Joined: February 09, 2005 Posts: 17009 Location: Retired South Florida
|
Posted: Sat May 04, 2019 9:31 am Post subject: Re: Vanagon Relay box/ electrical issue |
|
|
Ahwahnee wrote: |
Of course terminal 30 is the ground on a Bosch relay but it appears in this case (fuel pump) that is controlled by the ECU, thus not a brown wire. |
Not sure about that. If you were switching a ground through a relay, then yes 30 would be a ground, but generally 31 is ground on vw wiring. As mark said 30 is usually constant B+ power. The relay will pass whatever load you wire it for. _________________ ☮️ |
|
Back to top |
|
|
Ahwahnee Samba Member
Joined: June 05, 2010 Posts: 9776 Location: Mt Lemmon, AZ
|
Posted: Sat May 04, 2019 1:39 pm Post subject: Re: Vanagon Relay box/ electrical issue |
|
|
Reply was pre-caffeine. I fixed it. |
|
Back to top |
|
|
Stephenchaumont Samba Member
Joined: August 03, 2021 Posts: 1 Location: NSW
|
Posted: Tue Aug 03, 2021 2:12 am Post subject: Re: Vanagon Relay box/ electrical issue |
|
|
I am currently putting my first t3 back together. I ought it after it had had an engine fire and sat for 6 ears in a shed. I have rebuild the heads and replaced the engine loom plus a few other things.
My T3 is a 1985 1.9 ltr wbbx with digijet fuel inhjection. The loom seems to be from a slightly different engine as there are 4 connectors going to the throttle body on the loom however there is only a single connector on the bottom of the throttle body on the engine.
anyway to my question regarding the pic above. The red wire in the image needs a wire run from it to the positive connector in the junction box as far as I can tell but I Need to work out where to run the white wire in that connector shown too?
If anyone could help me that would be greatly appreciated.
Thanks |
|
Back to top |
|
|
Vanagon Nut Samba Member
Joined: February 08, 2008 Posts: 10347 Location: Sunshine Coast B.C.
|
Posted: Tue Aug 03, 2021 11:29 am Post subject: Re: Vanagon Relay box/ electrical issue |
|
|
Stephenchaumont wrote: |
....
My T3 is a 1985 1.9 ltr wbbx with digijet fuel inhjection. The loom seems to be from a slightly different engine as there are 4 connectors going to the throttle body on the loom however there is only a single connector on the bottom of the throttle body on the engine.
.... I Need to work out where to run the white wire in that connector shown too?
|
Your harness is likely for the early '85 and is set up for the older style dual switch. During 1985, the later style (as used under Digifant) "single" switch was introduced. It uses a 2 pin connector.
Include Mk2 VW's while searching for the older style throttle switches. IIRC, some use the same or very similar switching arrangement.
In the diagram in this thread, though it's shown as a striped wire, a white wire from ECU 21 connects to a T2. Use VOM to confirm if white wire at the connector connects to ECU 21 ? If I'm correct, that wire should also trace back to 50 at ignition switch.
Neil. _________________ 1981 Westy DIY 15º ABA
1988 West DIY 50º ABA
VE7TBN |
|
Back to top |
|
|
|