Wiring questions

I currently have everything under the dash torn apart and thought it would be a good time to fix a couple of problems that have existed since I built the Speedster several years ago. I wired the car myself but electrical is not my forte. Here are two problems and one question:
1. Windshield wipers have little or no guts. They are slow without wiper blades and barely move with the blades attached. I've checked to make sure everything is moving freely and nothing is binding. As best as I can see there are five wires coming off the wiper motor: black, brown, black with yellow dashes, black with white dashes and green. The first three are wired and the last two are capped (unused). Donor was a '76 Beetle and I can't find my electrical diagram for this car. What is the purpose of each of the five wires and am I using the right ones?
2. Everything else works under the dash expect when I turn on the headlights the readings on a couple of the gauges drops. My guess is it may be a grounding problem but, if that's correct, how do I find it? Or could it be something else?
3. I installed a set of 5" sealed beam fog lights and am thinking the simplest method to hook them up is to tap into the headlight circuit for power, with a seperate switch to turn them on/off. Is this reasonable or should I consider running a seperate circuit and fuse? Currently using a 15 amp fuse for the headlights, is that correct? What should the correct amp fuse be if the fog lights were put on a seperate circuit?

Bruce: sounds like, in general, you have a grounding problem in your dash.

I don't have a wiring diagram for a Beetle that new, but I may be able to find one on the web. Anybody got a '76 Beetle wiring diagram to help Bruce out?

Anyway, let's try shot-gunning the gauge problem:

Get a length of 12 or 14 gauge, stranded wire (and maybe some alligator clips).

Find a ground point on the gauge that moves when the headlights are turned on.

Attach one end of the test wire to that gauge's ground point (there should be a 14" fast-on tab for ground, or you can use the screws that hold the gauge to the dash - just make sure the wire is securely attached).

Turn on the headlights and note the movement of the gauge

Attach the red (+) side of a 25 volt voltmeter to the other end of the test wire and the black (-) side of the voltmeter to a known ground point on the car - there should be no voltage showing. If there is, you're probably not on a ground point on the gauge.

If the VM shows no voltage, remove it and attach the bare end of the test wire to that known ground point while, at the same time watching the gauge for meter movement. If the gauge movement returns to "normal", then you have a grounding problem in your dash which must be corrected. Turn off your ignition and headlights and think about attaching a better ground to your gauge and wiper motor circuitry.

If the gauge doesn't change when that ground is applied, then maybe you have a poor connection in the +12 volts feeding your gauges. gotta be one or the other.......

This help?

Once we know what the wire colors do on the wiper we can begin to attack that problem. I know my '69 VW used brown for ground under the dash, but American cars often use Green so we'd best find out for sure first.......

gn

Oh...the fog lights!

I always use an aux. light relay (NAPA, Autozone, etc.) and drive it (the relay coil) through a switch to the 12V accessory circuit, with the other side of the relay coil to ground.

Then run a fused 12V to the feed side of the relay, and the lights on the other side of the relay. That way the feed to the aux. lights won't draw down your headlights with their current needs, and you control the fog lights with your dash switch.

Another approach is to drive the relay off of low beam from one of the headlights directly (no additional switch). That way, there is no dash switch, and the fog lights always come on with low beam (but are still on a separate 12V circuit).

As for fuse size for the fogs, what are their combined wattage rating? Need that to figure the fuse size.

gn

I just went through this, and I wish I had my electrician friend here to explain. The wires...one is, of course ground...one of course, is hot.....one is for slow speed. one is for high speed......and my friends the last wire has something to do with "repositioning" the blades back to the return position at the winsheild.


Gclarke "The vacaville Guy"

Yup, that makes sense, especially the 12V lead for parking the wiper arm. Now if we just had one to open up and look at or someone who knows what each color/function is.........?

Some fog lamps can over heat some cheaper relays and fry them

I have found, that a 60 amp. Delco air conditioning relay is super heavy duty, and can handle continious larger voltage loads.

Gordon, My electrician friend just found the Ground ( grounded it on the battery -) and then put the + to each colored wire , and determined what they did.....fast wip, slow wipe etc.


Gclarke "The vacaville Guy"

Bruce: Almost forgot my foglight plan. I'm using a 30 amp relay. I'm powering the coil with ign. switched 12v.(thru toggle switch). I'm mounting the relay next to the battery up front(next to my airhorn relay) with 12v. fused power from the battery to the relay and out of the relay to the lights which are right there below. I'm mounting the lights behind the horn grilles.

BD

My fog lights are hooked up the same way as Bill's lights. It's easy if your battery is located in the front. I have mine on a separate dash switich. I wanted to have 'daytime' driving lights, so I wired the switch through the ignition switch. If the ignition is off the lights won't go on. It's a fail-safe system that I need in my old age.
Ron

Thanks guys, I'll have to do some checking based on your suggestions.

I am using an aftermarket, two-position pull switch for the wipers so will have to compare the numbers you provide which I assume are for an original-type switch. The meaning of the wire codes will help alot. I am not using the green wire (park) which means I have to manually shut them off to park 'em right. I am not using the black/white wire (ign switch) but have them wired to the "switched" side of the fuse box so the key must be turned to make them run. I am getting the slower speed for both positions so something is not right there.

Wiring 101 question: What is the purpose of the relay for horns and lights? I have a relay on the horns, do not recall having a relay on the headlights (should I?). I have a 20-amp toggle switch but not a 30-amp, so will have to upgrade.

Bruce/Gordon: As this is on the to do list I did some home work. I got on vintagebus.com's wiring page and used the diagram for a 76 bus as the bug list didn't go to '76. but the colors matched your motor. The way I see it is: Wires from motor:
Black- Lo Speed (#53 on switch)
Brown- Grounds Motor (From spade lug on motor itself)
Black/Yellow- Hi Speed (#53b on switch)
Black/White- Ign. Switched 12v.to switch#53a
Green- "Park cam" in motor (#53e on switch)
I'm not the best electrician but I know some. You can pull up the diagram up I was looking at here: www.vintagebus.com/wiring/bus-76.jpg
It takes awhile to load, but is easy to read.

BD

PS. My switch has a #30 on it for ign. switched 12v. Which makes me wonder about the blk/wht wire. My switch didn't have a 53e that I could find.

Bruce/Gordon: After working with my wipers all afternoon I managed to
get the second speed to work, but couldn't for the life of me get them to "park" in the down position. I'm wondering if I have read the diagram wrong about the green wire or if my motor is defective. The black wire did get me slow speed and the blk/yellow got me high speed but I got nothing with the black wire with white tracer or the green wire. I did find a spade lug on the motor itself for a ground and connected that to a good ground. Time for some gin and juice to regroup!

BD

PS. I believe relays are used so as not to pull high amps thru toggle switches burning them up. I guess if you have a 20 or 30 amp switch
it May be ok but don't quote me.

Bruce: I am responding to your question on the reason for using relays on horn and lighting circuits. Relays allow you to use low ampere switches on the dash and avoid the need for large diameter wiring to these switches. In addition, relays keep high ampere power wiring as short as possible, thus reducing the voltage drop in the wiring and putting the voltage where it does the most good (directly across the horn and/or headlights). In addition, low ampere dash switches usually have a better "feel". That is, they operate very easily with little effort.

As an added measure, I usually install a diode across relay coils to prevent inductive spikes (created when you switch a relay coil off) from being "seen" by the controlling relay switch. (These spikes can eventually ruin the contacts on the switch.) If you install a diode (such as a 1N4004) make sure that the arrow is pointing towards the + terminal of the relay coil.

Bill - Misery loves company!

Brian - Thanks for your explanation of the relay and the use of the diode sounds like a good suggestion and I'll give it a try.

The wiper switch is an aftermarket and believe it was designed for lights as it has the indications of HEAD, PARK, TAIL and BAT. Here's what I found: The Black wire (Lo speed) is connected to the "PARK" post, the brown/white wire (Hi speed) is connected to the "HEAD" post, the black wire (ground) is connected to a terminal block where many ground wires are connected and a wire from the terminal block (switched with the key) is connected to the BAT post. Seems this should work properly. The only thing I can think of is a weak ground...what's thet best way to test for this?

I'll look for the spade lug on the motor, maybe a ground wire to that is something that's missing.

I know nothing on this subject.... just printing out some great knowledge and ideas from thses posts for my workshop file.

Thanks everyone.

Bruce: To test for a weak ground, simply lift the black ground wire, tightly wrap a test wire (of least the same gauge) to it and run it to the (-) terminal of the battery. This by-passes all existing grounds and takes you straight to the source (ground) on the battery.

I found this site with askjeeves.com. It does a pretty good job of
explaining relays:
www.madelectrical.com/electricaltech/brighter-headlights.shtml

Bruce: Your wire color/functions in your last post don't match what we got from Bill (or you from an earlier post).

Bill gave us:
Black - Lo
Brown - ground
Black/yel - Hi
Black/white - switched 12V
Green - constant 12V (for Park)

And Bruce gave us:
Black - lo
Black (another?) - ground
Brown/white - hi
Black/white - Unused?
Green - unused?

I'm assuming what Bill gave us is (a.) correct and (b.) matches an earlier post from Bruce, so let's run with that assumption.....

First, getting the wipers to run full speed....
Pull the wiper motor brown wire from where-ever it is and apply it to a good, solid ground somewhere under the dash (you might even try several places to see if any make a difference). If any make a positive difference your old ground point is suspect and you'll have to find out why or move to a new, better ground point.

If no other ground points make a positive difference, then return to the original point, and remove the black (lo) wiper motor lead from where-ever it is and, using a jumper wire, connect it directly to the "+" terminal of your battery. Hopefully, that should give you a good low-speed action. If it does, then pull the Black/Yellow lead and try that attached directly to the battery. If neither show an improvement over earlier conditions, then your wiper motor is suspect.

If they both improve over original, then try a different source of 12 volts to your "bat" terminal on your switch unill you find one that gives you positive results, as I believe your "bat" source isn't up to snuff.

You headlight switch should be wired thus:
Black - park (lo speed)
Black/Yel - Head (high speed)
Switched 12V - Batt

From Bill's information, The remaining wires on your wiper motor should be:
Brown - ground
Black/White - switched 12V
Green - constant 12V (so it has power to return to "park" when the normal switch is turned "off")

That should do it.......let us know how you make out.

Brian.......when will you be boating up North?

gn

Gordon,

I screwed up when I typed my message above. My current wiring is actually: Black wire (Lo speed) is connected to the "PARK" post, the black/yellow wire (Hi speed) is connected to the "HEAD" post, the brown wire (ground) is connected to a terminal block where most of the ground wires are connected and a wire from the terminal block (switched with the key) is connected to the BAT post. Sorry for the confusion. I'll try your testing suggestions tomorrow. Thanks

I was roaming on the Shoptalkforum on the subject and found some posts
saying the park wiring varies. Some models had right hand wipers and some left. They each had their particular matching switches. One poster mentioned blowing fuses when trying to get the park wire to work. I blew about 4 fuses, so I'm just gonna be happy with the two speeds and manually park them. Taping up the green and Blk/white wires.
Bruce: Another good tech site is www.the12volt.com and another with great diagrams is vintagebus.com.
Anywho, it's on to the foglights and windscreen washers.

BD

Bill,

Thanks for the info. Too bad you and I don't live closer, our project lists sound almost the same. No Speedster work today, my wife is anxious for cabinets in the den so today was sawing and sanding.

You guys sound like me......I'm doing Urban Renewal on the cellar stairway today - sheetrocking and moldings.

I looked for my old VW wiper motor assembly to no avail - guess it got tossed when we moved here, but I do remember that there's a small box on the wiper motor assy, with a lid on one side which contained the wire terminals and the "park" switch. Pull the lid, look inside and you'll at least know which wires conform to parking the wipers and how they're run.
I always find myself blowing fuses when I try to second guess what's really going on (and then later you say "Shoot! THAT's how it works!!")

gn

Yelp! It can get confusin.
To help me in the future, When I need to work on my car
After I drew up my diagrams, of how my car was wired. I took color pen markers and colored coded all the wires on the drawings. to 1970 beetle codes. I tried to stick to that year, and Vs Spec's as much as I could.

Their not super neat, but are very helpful.

Yeah, I've been thinking of drawing up mine, too, especially since a lot of it is custom, but the thought of going through all that makes me want to go off and do other things. Bet'cha I'll be forced to do it one day when I can't find a problem!!