Re-wiring crossroads: OEM or Watson's

[Gumby_Mac]

I plan to keep on using the wiper switch on the column. I bought a variety of switches like an off-on-on for the headlights (park, park/headlights), a momentary toggle for a wiper pump, the hazard switch, and three on-offs for whatever else I might need someday.

This was the only diagram included with my switches but I also found this write-up online for the wiring:

[Ol'fogasaurus]

Gumby_Mac, the top book by Jim Horner is a good "wiring from scratch" book to have. It was written in '87 and my copy is from the 28th printing; I have had it a long time. It has VW based diagrams as well as Pinto based diagrams (among others) which a lot of kit cars wire to. I think there is more than enough relevent information for what you want to do even though automotive electronics has changed some. I learned a lot from the old Petersons Basic Ignition and Electrical Systems No.5 from '77.

After doing wiring from scratch a few times you will develop your own opinions’ (based at times on what you and other people have done) on how things should be done.

Have fun and don't let the hard times get to you.

Lee

[Marc]

I may try to decipher that chart sometime when I've embibed fewer adult beverages, but it's not germaine if you're planning to use the stock `72-up column-mounted wiper switch and compatible motor. That configuration has the advantage of being compatible with the water-pumper intermittent-wiper relay setup...Chris V can fill you in on that.

[Chris V]

Here's the best write-up I've seen on the intermittent wipers:
http://www.superbeetlesonly.com/forum/i ... opic=12291

[Gumby_Mac]

I know I might know the answer to this after I finish the electrical book, but I'd like to go ahead and order some of this stuff. Since I don't have my original fuse block and I don't feel like cutting the hole back open in the dash, could I use something like this instead?





And what about relays? What do I use to mount those under the hood? Originally they were on a second row of the fuse panel. Those Painless fuse blocks look pretty nice, but they're not cheap (compared to the blocks pictured above).

[Chris V]

Those type do not have a common bus-bar traveling through them - they're just a gang of in-line fuse holders essentially. They can be modified to work if you're willing to.

You might be able to use an OEM BayWindow panel w/integral relay holder since the dash has been welded-up; here's the second one in our Bus for reference:

[Gumby_Mac]

What about something like this? It has a negative and positive bus:

Blue Sea Systems, ST Blade Fuse Block With Cover - 12 Circuit with Negative Bus. Compact ATO/ATC fuse block consolidates branch circuits and eliminates the tangle of in-line fuses.



• Positive distribution bus with #10-32 stud
• Fuse blocks with covers include 20 write-on circuit labels
• Tin-plated copper buses and fuse clips
• Accepts ring or spade type terminals
• Accepts ATO and ATC fast acting blade fuses

[Chris V]

I've used a few of those and have been quite happy with them; matter of fact I really had to stand up for 'em when I put one in a racecar, short track racers fear fuses for the most part. I've never heard of any bad press for them either, and one of the fuses in the racecar even ended-up protecting the tach from an internal short a couple times...

In Dad's car the front may be a little busy due to packaging constraints not obvious - but I've got that same Blue Sea panel pictured mounted on the rear package tray near to the passenger wheel-well and it's fairly clean. I mounted a 75A relay beside the panel along with a starter solenoid relay and also a rear window defrost relay (changed the polarity of the rear heated glass from equipped)...and while creating the new loom instead of routing the ignition switch #15 - the black coil wire to the fanshroud as equipped, I ran it (in 20awg) to trigger a large 75A relay(intended for electric fans on watercooleds) that powers the Blue Sea panel and then assigned one of its fused locations to the coil and ran a new wire to the fanshroud. It essentially splits up the demands of the car at the windshield - The back-up lamps are also fed power off a dedicated circuit on the Blue Sea panel now - which is to say a much better arrangement than stock - where the power was shared among the ignition coil, carburetor, and back-up lamps - and only the lamps were fused.



Efficient auto electrical is about finding the minimalistic components for the installation while still providing safeguards - and while VW failed in fuse assignment & relay design for the most part - the rest of the wiring system provides a solid foundation to tweak. Over-ride switches or 'switched switches' do come in hand from time-to-time.

I didn't like to go find Dad to jumpstart him when he left something-on by accident - So I got him a jumpbox, but it was a bit of nuisance to use. So in his latest car I added the Dakota Digital product that has a voltage-monitoring circuit to turn-off features one might leave-on. He came home ticked-off one night when the module got wet and his lights didn't work - but he's also never had a dead battery. He was upset, but it's hard to fault the thing for not working wet - learned a lesson about putting his trunk back together and covering it-up. We couldn't of had a more pleasant experience since; As I mailed the module in for repairs, for free turns out, even being frank about it getting wet - got it back in no time to boot.

[Gumby_Mac]

So looking at that Blue Sea block, I see the "+" terminal at the bottom which I assume feeds the positive bus and the "-" terminal at the top which would go to a ground. What are the 12 screws under the "-" for? Are they just additional grounds?

[Chris V]

They're just convenient/cleaner if you have lots of little grounds that can be run a short distance and requires only one larger ground from the panel "-" to somewhere on the chassis. Here you can see there are just a few small things that are grounded directly at the racecar's panel - so the wire from "-" to the chassis in this case is quite small - but also quite short...DC electrical systems are a poor choice for carrying current over distance - so the shorter the path can be, the better. We did this entire car on the cheap, but the electrical system was the icing on the cake, aside from the panel and a couple bags or ring terminals I think everything was scavenged from junk cars/trailers...I used a rear window wiper relay to give the driver intermittent wipers on a push-button so as to keep the wear on the Lexan windshield to a minimum.

[Ol'fogasaurus]

Don't forget, the ground wire should be the same gauge as the wire it supports. When using a bussed terminal I come into it with at least a 8 ga wire if I have any more than a few grounds supporting hot wires comming off the terminal.

Lee

[Chris V]

#8 would be overkill for most applications...which is to say that #8 is larger than any single wire other than the battery-to-start cable in a stock ACVW.

The picture of the racecar panel may be a bit misleading - the 12V+ (coming from the back of the start motor) is WAY overkill for the application - but it was free

[Ol'fogasaurus]

But if you are going into a terminal strip with many branches hanging off it, the draw (remember, the work is done by the neg. side as I remember) could easily add up to an 8ga wire. As I remember, when you use an AMP gauge, often due to the long run (Vdrop = Current X Distance(Ft) X 2 X Ohms per 1000Ft x 0.001 or http://calculator.net/voltage-drop-calculator.html),... 8ga is what is usually called for (I still use an AMP gauge although I currently don't have it installed on my buggy but that should be soon resolved).

Lee

[Chris V]

For most applications I see no need to ground many things at the negative bus, when we're talking about cars with steel chassis (and 99% also have steel bodies/fenders) afterall - so the whole frame is a conductor in parallel with several tiny screws on a fuse panel, but there are many other places more efficent to terminate grounds. Only things within a few square feet may be relevant really, otherwise there's probably a different means much shorter. For instance in Dad's car I've grounded the power seat motors and heaters fed off this panel directly to the seat brackets rather than bundling a wire several feet away - making it less efficient.

Wire lengths shock be kept to a reasonable minimum whenever possible, and when having to run 'longer' circuits consider running 'low current signal wires' to relays & fuses closer to the device you wish to control.

[Ol'fogasaurus]

True except for two situations. 1) I have a glass buggy and have worked on "rails" that somewhat negates that. 2) as metal gets ages, like us (it doesn't work as well as it used to). Most of the time you don't know who has welded, bolted, glued on it and how clean they were and how much rust and crap that is on the pan or body (remember that electricity like stress likes to travel using the easiest route which is the outside surfaces of the conductor). Add to that, that &*%#$ braded ground strap is a pile of El Toro poo-poo; it was used in older American cars also and was always a pain in the rump.

If I can, I ground with wire but then I am not doing restorations’ either.

Lee