1981 Vanagon Radio Install - fuses? power?

[little_waters]

I'm installing a new radio in my van. Yay no more cassettes! Connecting everything was mostly straight forward except I'm a bit stumped with the power supply (constant yellow, accessory red and illumination orange).

I ended up doing what the old radio had set up. The old radio was wired into the constant power going to the cig lighter (both the constant power line on the old radio and the wire labeled ignition were on this line). What I was going to do was hook up the constant power and the illumination wire to the same power line and for the accessory wire I'm not totally sure...? Should I/could I also piggy back on the same line? I've looked on the forums and there are lots of suggestions to connect it to the ignition. Is the ignition switch/buzzer the black/white wire? Can I just tap the accessory wire into that wire? Will this help stop the radio from draining my battery if I do this?

And finally do I need to change or add any fuses (either in my fuse box or inline?)?

First time radio installer here, sorry if these are silly questions
Thanks!

[Wildthings]

First off if you hook your illumination circuit up to constant power it will be on the whole time and slowly run your battery down, at least if you have the face plate installed and closed. You want to hook the illumination circuit up to the wire that powers the dash lights, or at least a wire like the "X" circuit that is powered only when the key is in the "RUN" position.

Second off do you want to be able to listen to your stereo when the engine is not running? If so are you comfortable with having to have your key in the ignition for the stereo to be on or would you rather not have the key in when camping and such for theft protection?

FWIW, the Vanagon does not have an accessory position on the key.

Many stereos have a way to depower the unit if you have both wires hooked to constant power. You might check the owner's manual for your stereo to see if yours has this feature. Removing or even just opening the face plate may accomplish the same thing.

[jismay]

At one point I had a head unit pulled from a subaru in my van. It worked fine, but I had it hooked to constant power, and I found that it had around a .5 amp draw all the time. It was enough to kill the battery in a day and a half. After I put a toggle switch in the circuit all was good. I just left the switch in place when I upgraded the head unit as it is convenient to control radio power that way for me.
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1970 Squareback with 1915cc dual 40idf
1979 Beetle Convertible
1980 Vanagon Westfalia
1989 VW Cabriolet

[little_waters]

Oh I didn't realize that about the illumination wire, good point!

I'm ok with the keys in the ignition method, but I also have an on/off switch handy as well. If I used the switch could I take the accessory wire and the illumination wire and run those both through the on/off switch and run them to the cig lighter constant power wire as well?

With my old radio it was a constant power drain if I didn't remove the fuse or disconnect the battery. Hopefully I can do it right this time around.

[little_waters]

One more question! Since I'm hooking up the new stereo to the cig lighter power do I need to worry about blowing the fuse on that line now? I believe it currently only has an 8amp fuse on it. Can I just change the fuse to something higher or should I add an inline fuse on the yellow constant power line to be safe?

[bluebus86]

[little_waters]

There is a fuse in the back of the stereo (it's not an inline fuse but a fuse that's actually built into the stereo and visible from the the back).

Just to verify I have the right idea I can run my wires through a switch (this will control on/off power to the stereo). Through this switch I will run my accessory and illumination wire. Then I will patch the the yellow constant wire directly to my cig lighter's power wire (this wire has constant power). I will also patch the two red and orange wires connected to my switch to this same hot wire from cig lighter.

Because the cig lighter is fused (8amp), and there's a fuse in the back of the stereo then I don't need to add an inline fuse. Is this sounding like a good plan? Thanks everyone!

[little_waters]

Ok so I set everything up, plugged it in and now my van has no power. Not even a light will turn on. The battery is fine, I checked it and it's charged. I'm seriously stumped on this. How can I start to trouble shoot this?

[Wildthings]

[little_waters]

Hmm there's no corrosion on it, the connection is looking pretty solid

[little_waters]

Ok so this is all really strange. If I swamp my old stereo back in the van suddenly has power and works totally fine. As soon as I disconnect it, or try to change to the new stereo I have no power at all, not even a light will come on in the van. Could the old stereo be acting as a ground for some reason for the entire van? Would this be why removing it is removing the power supply? I'm so confused.

[bluebus86]

no lights at all?? no dome lights? tail lights, head lights with key turned to run? no wipers? no emergency flashers? no starter motor? please test these all and see if the power loss is isolated or not, is every thing dead?

I cant think of a single fault that would kill every thing except a fault at battery or its ground strap. or maybe the disconnection of a power lead maybe the one at the fuse panel area?
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[little_waters]

Every single thing was dead. No dome, tail, head light, nothing when I turned the key etc. I checked all the fuses, checked the battery and they were both good.

If I put the old unit back in everything started working again (so weird!). So I started looking to see if it was a grounding issue. I'm not sure how it did this but somehow, I do believe the old stereo was acting as a ground for the van. I started by cleaning the negative battery wire and it's connections. Tightened everything up and tried connecting it again and without the old stereo. This time it worked!

So... if anyone else has this issue (probably/hopefully no one else does) but that's what I did to solve the problem. So relieved that was all it was. I was dreading having to check all the crazy wiring the PO did on the van.

[Wildthings]

The battery post need to be clean shiny metal as do the inside of the cable terminals. The black coating that builds up on the metal surface over time will not conduct electricity. Lathering either Vasoline or dielectric grease on the post and cable terminals before and after hooking the cables back up will almost stop further corrosion.

A wire brush will clean the post and a pocket knife can be used to scrape the insides of the cable terminals. The special battery post-cable terminal tools are nice, but not at all necessary.