Run my 1982 Westy fridge off aux. battery?

[rsvp]

HI all,

I'm trying to run my fridge in my 82 diesel westy THE PHOENIX off a 2nd battery... Gowesty says it's not easy. their $.02 below...

PER GOWESTY: *80-83 Westy Owners: This kit will not power your refrigerator off the auxiliary battery, as there is no simple way to do so. This kit merely allows a 2nd battery to be installed, charged and isolated from the main battery when the ignition is off. It is up to you to wire all accessories to it.

Why is that? I assume it can be done... is there a writeup about it somewhere?

thanks,
Steve

[SCM]

I can't help with the wiring but understand that the stock 3-way fridge (propane/AC/12-volt) was never really meant to run off of the battery for very long. The 12V position was to allow it to run off of the alternator while driving and then off of a battery for a short time while you were pumping gas, running into a store, etc.

So, even if you figure out a way to connect it to your battery, the performance may not be what you expect (i.e. very short run time).
_________________
'91 Westfalia GL Automatic (GTA "Turbo" Rebuild w/Peloquin) and 2.3L GoWesty Engine

[sped372]

Stock setup taps into the alternator indicator (dummy light) to engage the relay for 12v on the fridge. Your engine's not running, the fridge isn't running on 12v either. Someone along the way could have bypassed it but it's a good safety feature to prevent accidentally running the battery down if you forget to switch the fridge over to a different power source while parked. Relay is in the compartment under the driver's seat.
_________________
1971 Karmann Ghia - 1600 DP
1984 Westfalia - 1.9 WBX

[E1]

If you have an inverter and a decent house battery, though I've never done it I see little reason you couldn't run the fridge via an inverter. Solar would assure it, I'd suspect.
_________________
‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[jmranger]

It can be done, but it's useless in most use cases. The fridge draws 7-8 amps, continuously. A typical house battery is in the 50-60 amp-hours range. So if you run the fridge until the battery dies, you'll get about 8 hours. If you stop when your battery is around 50% (so your battery still hold a charge one year from now), you're down to 4 hours.

If it works for you, sped372 gave you what you need above: just reconfigure the trigger of the fridge relay.
[Edit: oops... This would allow the fridge to run with the engine not running, but if you only do that, it would still draw from the main battery. crazyvwvanman got you covered for the battery switch below. My bad.]

[DamonAndTheSea]

What jmranger said.

I wouldn't try to run the dometic off an aux battery unless I had 400 amp hours of storage 600 watts solar and an ACR to charge the battery bank from the engine when you find yourself below 12.2v. If you install a modern 12v fridge (TF49 or TF65 being popular options), then you'll reduce power consumption by 4x!

The dometic @ 8 amps per hour = 192 amp hours per day.
Truck Fridge TF49/TF65 @ 2 amps per hour = 48 amps per day.

200 watts of solar with a 100 amp hour battery, mated to a good programmable MPPT controller is enough to keep a modern 12v fridge + basic peripherals running happy 24/7 in sunny conditions.

[rsvp]

Hey All,

thanks for your thoughts

Apparently, the early Westies did not have that relay under the drivers seat, as do the later model Westies, so I'm trying to find out how to rig this not using that under-seat relay.

As suggested, I am trying to set up a solar system, and will probably not be running the electric fridge constantly on 12 volt... But also don't want to chance running down the starting battery.

[crazyvwvanman]

So you have carefully verified that your van has no fridge relay under the driver seat?

It is simple enough to wire the early Westy kitchen to an aux battery. Under the driver seat is a fused wire that brings 12v power to that area from the dash. You need to unhook that wire from the dash connection power feed and connect it to the aux battery power instead.

Mark

[rsvp]

Thanks Mark,

Yes, I am certain there is no relay… And I agree, it seems very reasonable to just hook that fused red wire to an auxiliary battery. I will do that. I am still in sure why Gowesty thanks that it cannot easily be done!


Regards,
Steve

[jmranger]

[crazyvwvanman]

Yes, he has a fridge relay, mounted to the top of the fridge. During early 82 models it was moved to under the driver seat.

The earliest full Westy wiring is missing in many versions of the Bentley. It is labeled wrongly in most of those version as being the same as other years wiring. The latest Bentley added it back after years of leaving that diagram out, while the earliest versions of the Bentley had it.

Mark

[rsvp]

I will check tomorrow, and see if I can find that relay on top of the fridge… I will also check my newest Bentley manual, to see if they actually show the proper wiring diagram.

Thanks again,

Steve

[wcdennis]

Absorption refrigerators are powered by heat.
When you run the Dometic on 12v you are powering a heating coil that is a poor substitute for the propane flame or the 120v heating coil. Propane is the best power source for the fridge when you are camping.

[rsvp]

Hi all,

I found both the relay on top of the fridge (in a fairly inaccessible spot), as well as the diagram in my newest version of the Bentley manual, which I keep in my van.

All that said, it does look like the easiest way to run everything is to power the red fused wire under the driver seat onto the auxiliary battery. I assume that this powers everything else on the kitchen cabinet, as well as the overhead light.

Is there any reason I should follow GoWesty's auxiliary battery installation kit wiring directions when they do into there later Westies?

If not, it appears much simpler to just hook That fused red wire to the auxiliary battery, instead of taking the system apart to try and wire it to that relay.

Thanks,

Steve

[dobryan]

Maybe I missed it but why do you not want to use the propane option? It is incredibly efficient.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

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[fxr]

[rsvp]

Hey Dave

There's sometimes that you need to run your fridge on 12 volts... even if it's not the most efficient way.

Up for Boyd's for MLK week?

Regards
Steve