| Author |
Message |
weekendr
Samba Member
Joined: August 18, 2021
Posts: 59
Location: Halifax NS Canada
|
 Posted: Fri Dec 03, 2021 9:33 pm Post subject: Early 1986 weekender factory dual battery wiring mystery |
 |
|
I have a early 1986 Wolfsburg Westy Weekender GL with manual transmission and air. It came with a removable cooler chest that plugged in beside the passenger seat and a second battery under the driver's seat connected to the starting battery/alternator by an ignition dependant 30 amp relay. The wiring in the battery boxes under my front seats does not look like it has been modified but I cant find a diagram in Bentley that explains it. I'm putting in a new LiFePO4 house battery, DC-DC/mppt charger and shore power charger. I want to make sure I don't permanently disconnect or short out anything important.
The original lead from the house battery is kind of melted at the relay, so I want to upgrade to larger gauge wire and replace the relay with the DC-DC charger. There are some original-looking wires attached to the relay that remain a mystery to me so far. I'm also a little bit suspicious that someone may have disconnected the relay and hooked it back up incorrectly
Photo above is the drivers side house battery wires and relay. The red (terminal 87?) and smaller red/black (terminal 85?) wires at the top of this photo are a mystery to me. The red is always hot. The blue one is ignition which trips the relay (terminal 86), the big melted red one below that is house+, the big red/white one at the bottom was alt/starter battery+, and the black one goes from House+ back to the cooler chest plug. (The little ones hiding underneath at top are for the seatbelt buzzer.) I cant figure out what the red wire which connects terminal 87 on the relay to something under the dash is for.
Below is a photo of the relay pins. It seems the center terminal is always connected to terminal 87. Mystery wire was on 87. Not sure if the house or starter battery was connected to the center terminal. Looks like there was some arcing on terminal 30 so that would be consistent with being attached to the melted lead from the house battery. It follows that both the starter battery and the mystery red wire were connected to 87. I'm thinking maybe the red/black wire on terminal 85 is the ground for the ignition trip circuit, but aren't grounds brown and wouldn't that just be grounded to the chassis instead of running back to the dash??
The house battery is long gone. On the passenger (starting battery) side the wires to the relay and from the house battery have been capped, but mystery red wire that was attached to 87 on the house side relay remains hot. It appears to go back from the relay towards the dashboard bundled with with the blue ignition wire and the red/black wire. Can anyone enlighten me?
The photo below is the starting battery wiring. You can see where the wires to the relay and house battery have been capped with shrink tubing. The small black wire goes to the cigarette lighter plug on the seat pedestal that powered the factory chest cooler. I think it was originally connected to the black wire coming back from the house battery. I am not sure what the four red wires attached to the positive post in two pairs do. Two appear burned. I want to replace and fuse them but I don't know where they go.
Can anyone clue me in on what the four red and red/white wires attached to the starter battery + terminal are? I'm guessing one goes to the fuse/relay panel and one to the rad fan, but can't figure out the other two.
_________________
Early 1986 Wolfsburg Westy Weekender 2WD GL manual with KEP EJ22 |
|
| Back to top |
|
 |
weekendr
Samba Member
Joined: August 18, 2021
Posts: 59
Location: Halifax NS Canada
|
| Posted: Sat Dec 04, 2021 7:12 am Post subject: Re: Early 1986 weekender factory dual battery wiring mystery |
|
|
Hmm, no suggestions. Maybe my query was too convoluted, or maybe this belongs in the lazy person's stupid question thread. Can anyone point me in the right direction to figure out the factory aux battery wiring on my van?
_________________
Early 1986 Wolfsburg Westy Weekender 2WD GL manual with KEP EJ22 |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32625
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
weekendr
Samba Member
Joined: August 18, 2021
Posts: 59
Location: Halifax NS Canada
|
| Posted: Sat Dec 04, 2021 7:34 am Post subject: Re: Early 1986 weekender factory dual battery wiring mystery |
|
|
| djkeev wrote: |
It's only been two hours on a lazy Saturday morning ......
I had an 86 "Weekender" with that setup but installed a house system so I ignored it.
I'm no help but I bet it is in the bentley in the camper wiring?
My Bentley is in my Van...... lazy Saturday..... it is cold outside...... |
Thanks djkeev,
I looked in Bentley. To the extent that I can understand these diagrams camper wiring appears to be very different from weekender. Can't find anything on early 86 weekender. Am in the process of continuity testing everything. Very confused. Cold here too!
_________________
Early 1986 Wolfsburg Westy Weekender 2WD GL manual with KEP EJ22 |
|
| Back to top |
|
|
Timwhy
Samba Member
Joined: January 01, 2009
Posts: 4002
Location: Maine
|
| Posted: Sat Dec 04, 2021 7:42 am Post subject: Re: Early 1986 weekender factory dual battery wiring mystery |
|
|
| crazyvwvanman wrote: |
It is pretty simple. All 5 spades of the relay are used.
Originally there were 2 red wires from the pass side battery box over to the driver side battery box.
One red connected from the main battery positive to the relay spade #30.
The other came back the other way, from relay spade #87 to the cig socket under the pass seat.
Another red went from the other relay spade #87 to the aux battery positive.
That leave 2 wires to go, that come from the dash to the driver side battery box.
The blue one went to relay spade #86 to trigger the relay coil from the alternator led circuit. This was to make sure the aux battery wasn't connected until the alternator was charging.
The last wire is a red/black that plugs into the relay spade #85. This acts as the ground for the relay coil. ( I prefer not to use this wire and I make a small ground wire and run it from #85 to the screw that holds the relay to the body.)
Mark
| tschroeder0 wrote: |
The relay has 5 positions and yeah i tried Bentley but man! Finding stuff on my 85 is tough
So, can someone tell me which wire from the relay goes directly to the aux battery, what i have is one red med gauge wire that crosses over to the main compartment but was not hooked up, ?? Maybe it went to the 12v plug for the little cooler?
Either way i dont know how my aux battery would get charged, sorry so confused
Thanks, todd |
|
_________________
'15 Audi A3 Quattro
'09 VW Tiguan (dead)
'87 VW Westy
'91 Tin Top
'90 Cabby
What the Westy wants the Westy GETS
http://www.thesamba.com/vw/forum/album_search.php?search_author=Timwhy&show_results=summary
http://www.youtube.com/user/TIMWHY2?feature=mhee |
|
| Back to top |
|
|
weekendr
Samba Member
Joined: August 18, 2021
Posts: 59
Location: Halifax NS Canada
|
| Posted: Sat Dec 04, 2021 8:09 am Post subject: Re: Early 1986 weekender factory dual battery wiring mystery |
|
|
| Timwhy wrote: |
| crazyvwvanman wrote: |
It is pretty simple. All 5 spades of the relay are used.
Originally there were 2 red wires from the pass side battery box over to the driver side battery box.
One red connected from the main battery positive to the relay spade #30.
The other came back the other way, from relay spade #87 to the cig socket under the pass seat.
Another red went from the other relay spade #87 to the aux battery positive.
That leave 2 wires to go, that come from the dash to the driver side battery box.
The blue one went to relay spade #86 to trigger the relay coil from the alternator led circuit. This was to make sure the aux battery wasn't connected until the alternator was charging.
The last wire is a red/black that plugs into the relay spade #85. This acts as the ground for the relay coil. ( I prefer not to use this wire and I make a small ground wire and run it from #85 to the screw that holds the relay to the body.)
Mark
|
|
Big thanks TimWhy,
This may have solved half of my mystery. I have a black wire going directly from AUX battery + back to the starter battery compartment. It is bundled with the cable from the starter battery to the relay. It is capped on the starter battery side. I assumed this was the passenger seat cig lighter socket wire. If my mystery red wire on 87 also goes back to that socket I think I know why it is hot, a PO wired the socket straight to the starter battery after removing the aux battery. I can't see in there because my seat swivel base is welded in but can test with meter, Mark's explanation is consistent with Bentley 97.34a which shows camper start battery on terminal 30 and camper aux battery on 87. Once again I was mistaken, I thought on my van AUX battery went to 30.
I still have to figure out what the two burnt red wires on the starter battery are for, I don't see six wires coming off starter+ in Bentley. In diagram 97.34a there is the big one to starter/alternator, a red to circuit 30 (ignition), and a red to 30 on the aux battery relay. My van has R/W to that relay, and there are two more reds and a R/W unaccounted for on the starter battery + terminal.
_________________
Early 1986 Wolfsburg Westy Weekender 2WD GL manual with KEP EJ22 |
|
| Back to top |
|
|
crazyvwvanman
Samba Member
Joined: January 28, 2008
Posts: 9935
Location: Orbiting San Diego
|
| Posted: Sat Dec 04, 2021 1:17 pm Post subject: Re: Early 1986 weekender factory dual battery wiring mystery |
|
|
There are some variations in how VW did the aux battery in the "weekender".
Earlier versions seem to get charging power to the relay from the dash fuse panel instead having a direct wire from the starting battery.
As to the 4 red wires at the starting battery in your photo, the 2 more factory looking red and red/white are what you thought, rad fan and dash fuse panel power.
The other 2 reds should be for the early West A/C setup.
If removing the relay the small blue and red/black don't have any purpose any longer.
Mark |
|
| Back to top |
|
|
weekendr
Samba Member
Joined: August 18, 2021
Posts: 59
Location: Halifax NS Canada
|
| Posted: Sat Dec 04, 2021 1:26 pm Post subject: Re: Early 1986 weekender factory dual battery wiring mystery |
|
|
| crazyvwvanman wrote: |
There are some variations in how VW did the aux battery in the "weekender".
Earlier versions seem to get charging power to the relay from the dash fuse panel instead having a direct wire from the starting battery.
As to the 4 red wires at the starting battery in your photo, the 2 more factory looking red and red/white are what you thought, rad fan and dash fuse panel power.
The other 2 reds should be for the early West A/C setup.
If removing the relay the small blue and red/black don't have any purpose any longer.
Mark |
Woo Hoo! AC wires! My AC is torn out so I can probably disconnect them! I may try connecting the small blue to my DC/DC charger so it will know when the van is running.
Thank you Mark.
_________________
Early 1986 Wolfsburg Westy Weekender 2WD GL manual with KEP EJ22 |
|
| Back to top |
|
|
khughes
Samba Member
Joined: July 13, 2013
Posts: 747
Location: Phoenix AZ
|
| Posted: Sat Dec 04, 2021 1:46 pm Post subject: Re: Early 1986 weekender factory dual battery wiring mystery |
|
|
Terminal 87 is a single terminal with two spade connectors. Take a look at the diagram on the side of the relay. Both wires to 87 are powered (connective with terminal 30) when with the relay is energized. Note that 85 is ground and 86 is power - makes a difference in this case as there's a diode between the coil and the 85 terminal to prevent backfeed. Don't think these are actually available any longer - unless someone here knows a source?
_________________
'86 Westy FAS GenV Turbo (Marvin) |
|
| Back to top |
|
|
weekendr
Samba Member
Joined: August 18, 2021
Posts: 59
Location: Halifax NS Canada
|
| Posted: Sat Dec 04, 2021 1:59 pm Post subject: Re: Early 1986 weekender factory dual battery wiring mystery |
|
|
| khughes wrote: |
| Terminal 87 is a single terminal with two spade connectors. Take a look at the diagram on the side of the relay. Both wires to 87 are powered (connective with terminal 30) when with the relay is energized. Note that 85 is ground and 86 is power - makes a difference in this case as there's a diode between the coil and the 85 terminal to prevent backfeed. Don't think these are actually available any longer - unless someone here knows a source? |
That confirms what I figured out so far. I just wasn't sure which battery connected to 87 and which to 30. And especially what the second wire on 87 was for. Didn't know about the diode on the coil. Not sure why that circuit is set up that way. When the ignition key is on the blue wire is powered and activates coil through 86. What is the purpose of the red/black wire on 85, couldn't it just be grounded to chassis? Maybe I am misunderstanding something. Wouldn't it make more sense to prevent backfeed between the battery banks than backfeed from the ground to the ignition?
_________________
Early 1986 Wolfsburg Westy Weekender 2WD GL manual with KEP EJ22 |
|
| Back to top |
|
|
weekendr
Samba Member
Joined: August 18, 2021
Posts: 59
Location: Halifax NS Canada
|
| Posted: Mon Dec 06, 2021 1:14 am Post subject: Re: Early 1986 weekender factory dual battery wiring mystery |
|
|
Still a mystery!
https://www.thesamba.com/vw/forum/viewtopic.php?t=...p;start=60
Turns out simd0ggie and tschroeder0 were both very eager to find out what the mystery red wire attached to terminal 87 of the aux battery relay is for. They have the exact same oddball factory wiring as me. They both posed the exact same question I did here back in 2012 and again in 2014 and 2015. crazyvwvanman said the wire might go to the socket that powers the portable chest fridge. It doesn’t. Not on these three weekenders.
The mystery wire is bundled in a black sheath with the blue alt wire and red/blk ground from relay terminals 86 and 85, and with the seat belt buzzer wire. This bundle disappears into the welded swivel seat base cavity and must come out below the van somewhere, presumably ending up behind the dash. The aux battery was apparently wired to the second spade of terminal 87 so it seems the mystery wire was always energized by the aux battery.
Has anyone with a chest fridge weekender managed to trace it to it’s source?
_________________
Early 1986 Wolfsburg Westy Weekender 2WD GL manual with KEP EJ22 |
|
| Back to top |
|
|
crazyvwvanman
Samba Member
Joined: January 28, 2008
Posts: 9935
Location: Orbiting San Diego
|
| Posted: Mon Dec 06, 2021 6:23 am Post subject: Re: Early 1986 weekender factory dual battery wiring mystery |
|
|
The 3 wires in a bundle come from the dash fuse panel.
That is the small blue, red/black, and thicker red.
The red should come from a P spade in early 86, to provide charging power to the relay pin 30. (this was later changed to get the charging power from the starter battery + terminal)
The relay's twin 87 pins are both aux battery power pins.
One takes charging power to the aux during charging and then brings aux power back the other way when not charging. This leaves the other 87 pin to feed power to the fridge cig socket. That will be charging voltage when charging and aux battery voltage when not charging.
I'm describing how things were wired originally and not how any modified van might be now.
The blue wire originally connected to the Bosch alternator D+ circuit for relay control but some conversions like Subaru have alternators that can't do this and thus they get modified wiring.
Mark |
|
| Back to top |
|
|
weekendr
Samba Member
Joined: August 18, 2021
Posts: 59
Location: Halifax NS Canada
|
| Posted: Tue Feb 15, 2022 9:41 am Post subject: Re: Early 1986 weekender factory dual battery wiring mystery |
|
|
| crazyvwvanman wrote: |
The 3 wires in a bundle come from the dash fuse panel.
That is the small blue, red/black, and thicker red.
The red should come from a P spade in early 86, to provide charging power to the relay pin 30. (this was later changed to get the charging power from the starter battery + terminal)
The relay's twin 87 pins are both aux battery power pins.
One takes charging power to the aux during charging and then brings aux power back the other way when not charging. This leaves the other 87 pin to feed power to the fridge cig socket. That will be charging voltage when charging and aux battery voltage when not charging.
I'm describing how things were wired originally and not how any modified van might be now.
Mark |
Thanks again Mark, you sure know your wiring!
With the help of your input I was able to trace the mysterious red wire in the bundle back to the dash fuse panel. It is the smaller red wire next two two large red wires in the top left of fuse panel photo below. Clearly factory. I think I will use it to power fuse 3 from my new aux battery to avoid running a new wire under the carpet. (While I do have a subie conversion, the blue wire may not be necessary as I am using a voltage actuated DC/DC charger.)
You say that red wire in the bundle brought power from the panel to charge the AUX battery in early 86 vans like mine. That would make sense but I'm still a bit confused. My weekender also has the factory red/white and black wires running directly back to the starting battery/chest cooler in a bundle as shown in the photo of the aux battery box below. Is it possible the dash feed to the aux battery became redundant when Westfalia ran the bundle directly to the passenger seat pedestal to power the chest cooler plug only found in weekenders?
Once I figure this out I need to decide whether to run a more robust wire (4-6AWG) between the battery boxes. My DC-DC charger pulls 30A max. Can I get away with using the factory R/W wire (looks like 10 AWG) with a 40A breaker for that 4 foot run?
_________________
Early 1986 Wolfsburg Westy Weekender 2WD GL manual with KEP EJ22
Last edited by weekendr on Tue Feb 15, 2022 9:48 am; edited 1 time in total |
|
| Back to top |
|
|
newt3
Samba Member
Joined: March 09, 2017
Posts: 30
Location: German
|
| Posted: Wed Feb 16, 2022 4:03 pm Post subject: Re: Early 1986 weekender factory dual battery wiring mystery |
|
|
http://www.t3-pedia.de/index.php?title=Trennrelais...6-30-87-87
->87 = P Fuse Box = +12V Main Battery
->other 87 = +12V@Battery Charger (to Charge Main Battery by 110/230V to 12V Battery Charger) = + Main Battery
->30 = + Aux Battery
->86 = D+ (blue) = G4 at Fuse Box = Generator D+
->85 = C18 Fuse Box = 50 Starter
means both 87 are the same pin in the relais.
it just hast 2 pins outside but inside they are the same.
so on pin is to have a connecting terminal for your 110/230v>12v batterie charger. |
|
| Back to top |
|
|
|
