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Wed Jul 16, 2008 6:44 pm

Hi all

1991 Multivan Westfalia - all stock

Factory dual battery setup. New main battery and Bosch relay, verified good auxiliary battery. Both batteries charge well and the van starts no problems.

Problem is: when the key is switched off all power is still being drawn from the main (starting battery). I used my volt meter and turned on several accessories such as interior flourescent, radio, parking lights etc. The voltage drop on the system all came from the main starting battery not the auxiliary. The auxiliary remained at full charged voltage ( forget the exact numbers but draw was definitely from the main battery). If I disconnect the ground on the main battery, with the key switched OFF the interior light goes out, telling me it is still drawing power from the main.

I believe my relay is good as its brand new, I switched it out sort of assuming it was the problem. However it appears that is not the case. How do I check for the proper signals to the relay. It appears to charge the batteries fine (blue wire?) but I believe the small red/black wire is the signal from the ignition switch...

What do I need to see on the red/black wire to know the signal to the relay is correct? 12V when the key is turned on?

Any help appreciated... we are going camping for a couple of weeks soon and I would like to get this working properly..

Thanks,
Eric

Wed Jul 16, 2008 7:50 pm

I just got the Gowesty kit. Didn't work. Called & was advised to detach the red/black (ignition) wire, connect a wire to ground from the same relay spade. IT WORKED!!!
There's something about the relay & diodes....
Anyway, just came home from a camping trip... everything is cool.
later,
Peter

Wed Jul 16, 2008 8:15 pm

Experts correct me if I'm wrong, but...

By default, the aux. bat only runs the fridge and sink pump. You have to do some re-wiring to get all the other stuff to run off of it. I rewired my stereo, all the camper components, and the rear lighting to run off the aux. I'm stoked now, but it took some work.

Wed Jul 16, 2008 8:26 pm

buseric wrote: Hi all

1991 Multivan Westfalia - all stock

Factory dual battery setup. New main battery and Bosch relay, verified good auxiliary battery. Both batteries charge well and the van starts no problems.

Problem is: when the key is switched off all power is still being drawn from the main (starting battery). I used my volt meter and turned on several accessories such as interior flourescent, radio, parking lights etc. The voltage drop on the system all came from the main starting battery not the auxiliary. The auxiliary remained at full charged voltage ( forget the exact numbers but draw was definitely from the main battery). If I disconnect the ground on the main battery, with the key switched OFF the interior light goes out, telling me it is still drawing power from the main.

I believe my relay is good as its brand new, I switched it out sort of assuming it was the problem. However it appears that is not the case. How do I check for the proper signals to the relay. It appears to charge the batteries fine (blue wire?) but I believe the small red/black wire is the signal from the ignition switch...

What do I need to see on the red/black wire to know the signal to the relay is correct? 12V when the key is turned on?

Any help appreciated... we are going camping for a couple of weeks soon and I would like to get this working properly..

Thanks,
Eric

I don't now if this will help but....

Without an aux battery, my stock '81 Westy had all the kitchen stuff (light, sink pump) wired to the starter battery so that I did NOT have to have the key switched on for them to work. I think that is the stock configuration. When I installed an aux battery, I moved the kitchen circuit and radio, to the aux battery. Still didn't need to have key on to use this stuff. (makes sense)

Do the Multi's come from the factory with an aux battery?

If not, it's possible the PO installed the aux battery for future 12V appliances, but left things like the light and radio etc., connected to the starter battery. ( I can't see why thought.....)

Do you know what appliances/accessories are connected to the aux. battery?

The blue wire is from the alternator. With the engine running, it turns on the relay so power from the alt is allowed to pass through the wire from positive of starter battery, so it can charge the aux battery.

With engine running, (assuming charging system is ok) you should see 12V+ at 87 of the relay. Engine off there is NO 12V+ at 87.

Thu Jul 17, 2008 3:02 am

sc-surfer wrote: Experts correct me if I'm wrong, but...

By default, the aux. bat only runs the fridge and sink pump. You have to do some re-wiring to get all the other stuff to run off of it. I rewired my stereo, all the camper components, and the rear lighting to run off the aux. I'm stoked now, but it took some work.

This van is factory dual battery 1991 Weekender, not full westy.... no accessories except the interior flourescenty. I assumed anything that has direct power with the key off would draw from auxiliary battery because the relay turns all current to auxiliary when the key is off. Is this not how the system works? I have all paperwork going back to original owner so I am sure it is a factory setup..

If nothing runs off the auxiliary battery then why would VW install one?

Thu Jul 17, 2008 3:43 am

sc-surfer wrote: Experts correct me if I'm wrong, but...

By default, the aux. bat only runs the fridge and sink pump. You have to do some re-wiring to get all the other stuff to run off of it. I rewired my stereo, all the camper components, and the rear lighting to run off the aux. I'm stoked now, but it took some work.

I'm no "expert", but you are correct, and a simple search (albeit a long topic) will yeild the willing a list of posts on how to re-wire the Vanagon to allow accessories to run off of the aux battery. If my old, aging memory serves me, it has to do with the cigarette lighter wiring, and opening (removing) a fuse once the mod was done. TENCENTLIFE addressed this, so look for his post/response in the search results.

We've got to promote that search tool; so many answers can be had if it were used, and the results read through.

Thu Jul 17, 2008 9:04 am

Quote: We've got to promote that search tool; so many answers can be had if it were used, and the results read through.

But if everyone did, this forum would die. What would we do if everyone found the answers that were already written? Writing them over and over and over again gives us something to do.

All kidding aside, the OP has a Weekender. As I understand it, the Weekenders got their aux battery for the sole purpose of powering a little electric cooler that came with them; not a built-in like the Westy's, just an ice chest that ran on 12V. There might be an extra interior light in there that I'm not sure about. But they didn't patch anything else over to the aux battery, even though they should have. They also should have put a 2.8 liter flat six intercooled turbo diesel in the back, but they missed that, too.

To power the basic things you would want running off an aux battery, you want to power circuit #3 on the main panel. That takes in the clock, radio head (not the band), interior lights, and cigarette lighter.

The simplest way to do it is to run a 10ga. wire feeder off your aux battery positive pole, beginning with a 20A inline fuse, and take the feeder and make it common with the positive feed on the back of the in dash cigarette lighter. How you route the wire is up to you. Once that's connected, unplug fuse #3 on the main fuse panel. Now all those loads are powered off the aux at any time. To switch them back, plug fuse 3 back in and remove your feeder's fuse.

Thu Jul 17, 2008 5:33 pm

tencentlife wrote: Quote: We've got to promote that search tool; so many answers can be had if it were used, and the results read through.

But if everyone did, this forum would die. What would we do if everyone found the answers that were already written? Writing them over and over and over again gives us something to do.

All kidding aside, the OP has a Weekender. As I understand it, the Weekenders got their aux battery for the sole purpose of powering a little electric cooler that came with them; not a built-in like the Westy's, just an ice chest that ran on 12V. There might be an extra interior light in there that I'm not sure about. But they didn't patch anything else over to the aux battery, even though they should have. They also should have put a 2.8 liter flat six intercooled turbo diesel in the back, but they missed that, too.

To power the basic things you would want running off an aux battery, you want to power circuit #3 on the main panel. That takes in the clock, radio head (not the band), interior lights, and cigarette lighter.

The simplest way to do it is to run a 10ga. wire feeder off your aux battery positive pole, beginning with a 20A inline fuse, and take the feeder and make it common with the positive feed on the back of the in dash cigarette lighter. How you route the wire is up to you. Once that's connected, unplug fuse #3 on the main fuse panel. Now all those loads are powered off the aux at any time. To switch them back, plug fuse 3 back in and remove your feeder's fuse.

I did use the search tool, 137 matches... I don't have that much time....I am living with dial up (21.4kbps) so even posting is an agonizing chore, let alone searching through a bunch of unrelated posts....And besides if everyone on this list has already learned everything about vanagons than I guess the forum must be redundant...

Back to the topic at hand... My van does not have, nor ever did have a fridge/cooler.... So what would be the point of having an auxiliary battery? If it doesn't run the westy flourescent interior light or the radio, cigarette lighter what is the point of even having it? If nothing ever draws from it, seems a little useless and unlike Germans and VW.....

I thought the relay was to switch ALL power to the auxiliary with the key off... How do I wire it up this way? It seems this would make more sense and would be simpler? That way if headlights left on etc... you don't drain the main battery....

Thanks
Eric

Wed Jul 30, 2008 8:20 am

to (try to) answer one of your original questions - as i recall in my '84, the red/black wire going to that relay is hot only when starting, and grounded when running. i believe it is floating when the key is off.

i think they use this wire as the ground for the relay, so that the voltage difference between it and the alternator wire is 0 when the starter is engaged, thereby shutting off the relay and any extra load on the battery during starting.