General aux wiring question


New member
Hi all,
I've got an '87 Westy and I've got the "add do-dads" bug big time. I've done some stuff already, but reading all this posts makes me itch big time to do more. :)

My real question is this, do you folks that do all this adding on set up like a new buss bar to tap into? Or do you splice in to power here and there? I've added the second battery under the driver's seat and can't decide if I should run my wires right to it, or add like a buss bar somewhere (in the cabinet?) to run all my wiring to? Just curious as to what you all would do or have done. Thanks
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Capt. Mike

There is no hard & fast answer because it will depend on your use, power consumption and what accessories.

If you have sufficent accessories to exceed the capacity of the standard Accessory fuse -- S3 on an '87 -- then it is appropriate to add a 2nd fuse box, available at most parts stores. This will simplify wiring and allow it to be located in a place much easier to access & work with.

Some accessories, such as auxilliary lights & instruments, will require power controled by the ignition system. Thus you will need to feed some of the fuses with ignition on power. Probably jumping from the input buss of shown at A8 in cirucit #11 [Note: all of these relate to the '87 only -- they will be differnet in other models. Consult your wiring diagrams.]

Other such as extra interior lights or DIN plugs will require power at all times. Thus they should be fed by jumping from a major power source such as D24 in circuit #4.

Finally, you will have to decide which, if any, circuits you want to feed from the auxiliary battery, remembering that they will be isolated from the main and dependent upon the auxiliary at all times. Since the auxiliary, if wired per VW, already feeds a fuse box behind the driver's seat for the fridge & sink, you might want to just swap that for a larger one.

In all cases, I suggest you use a box consistent with your vehicles existing fuses. The main box in an '87 uses standard ATO style; the auxiliary box in a Westy uses the ceramic in-line style. You DO NOT want to add another set of spares to consider.
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New member
Fan fuse

I have a 84 Westy that had a 25A fuse for the front defroster motor. The drawings say it should be a 16A. Any thoughts on why a 25A fuse was put in?

Capt. Mike

:rolleyes: In simple terms, stupidity! The fuse is to protect you from overload or short. It's size is determined by what it is expected to run and the characteristics of the wiring, motor, etc. of that load. Go back to the 16A. If it blows, that means you have a problem with the blower motor or wiring that needs to be fixed rather than let the bigger fuze overload the wiring and burn up the car. Of course that fuse also feeds he windshield wiper & washer if you have to go looking for excessive draw.
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New member
I have a 76 westy and I just had an external oil cooler and fan added. The mechanics hooked it up to main power so if the thermostat is >190f it stays on. Should I move the power to ignition side? Which fuse is recommended? How


New member
General aux wiring que

Maybe years ago, with the rather basic wiring, things were simpler. Now with almost everything wired to the max, consider the drivers door panel, there must be hundreds of individual circuits and considering there are only 10 primary colors, the combinations must be amazing If each manufacturer standardized on a color code it might be more manageable. Add into that the discoloration because of aging, heat and grime, it is no surprise that military aircraft uses numbered wires rather than color codes.


Neither do I
Could be quite a bit of friction inside the gear box- maybe the red head gear box might reduce the load on the input shaft ?
maybe later I will upgrade


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