Short Circut

Gotta love that wiring . . .
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danny910

Short Circut

Post by danny910 »

:( Had alternator rebuilt & put in new battery but something keeps killng the battery. When I put the cables on the battery, there is a spark even though everything is turned off. :( :( :( :( HELP!
mbouse

Post by mbouse »

having read a post at another forum...first question. You are certain you are putting the ground on the negative terminal, and the hot wire on the positive terminal?

sounds indeed like there is a short. based on your brief description, i surmise that the shorted wire is not fused. describe the steps you have taken already to find that short. have you:
1. traced the hot wire allthe way from the battery to the starter, making sure it is not touching bare metal with some worn part of the wire insulation?
2. traced the wires from the alternator to insure that each of them does not touch ground?
3. inspected the white connector block behind the ignition switch to see if it is burnt, or any connections melted?

etcetera...what have you done? what have you eliminated?

do you see any smoke?
danny910

Post by danny910 »

Haven't had alot of time to trace it all the way down yet. I do know I have some melted wires under the dash (mainly the raido area). I'm going to try to find time this weekend.
So Cal Mark

Post by So Cal Mark »

remove the neg batt cable, take a single filament bulb (like a taillight bulb) and touch the center contact to the battery cable. Then touch the batt cable and touch the side of the bulb base. If the light comes on you have something drawing power. You can then take out fuses one at a time and see if the light intensity changes. If nothing changes, unhook the alternator wiring and check the bulb again
Make sure the ign switch is off and everything else is turned off.
Mark_vaughn

Post by Mark_vaughn »

Don't you love it when you try to make a small fix and uncover a several more problems!!

I have a short in the second fuse from the right . I think it is the windshield wiper motor. Wipers and blinkers are not working now. The previous owners have butchered some of the wiring. I have in-line fuses all over the place. It looks like there was a different radio at one point, so there are several spices in that area. Not to mention the loner wires that look like they should be connected to something, but are not. Oh and to top it all off, my heater core is going to start leaking soon, probably as soon as I get everything back together.

So my question: does anyone have a good wiring diagram they could send me? I have the Haynes manual and it is OK, but I think I need a little more than that.

If someone will make a copy for me, I will scan it to PDF for everyone to have. This is obviously for educational purposes only so we have no copyright issues.

thanks.
Mark_vaughn

Post by Mark_vaughn »

Here is a pic for everyone to laugh at.

I have already found a few grounds that were by-passed for some reason.

I need some help on one thing. Where is the wiper motor? Haynes says behind the dash, and I don't see it yet.


Image
Mark_vaughn

Post by Mark_vaughn »

Found the wiper motor. It is kindof under the dash, but you get to it from outside the car! Way to go Haynes Manual!!

BTW, Anyone know how to test the wiper motor?


Take a look at this, did they come like this or is this some bad body work at some point?

Image

Image

This is after I pulled some of the caulk type stuff off with my fingers...

These cars have hidden secrets everywhere!!
Mark_vaughn

Post by Mark_vaughn »

One more question.

That flap in the center of the car, in the picture above. Is that controled by one of the heater levers in the car? That one is obviously rusted in place, but may be salvaged.
mdrburchette
Posts: 5754
Joined: Wed Jan 25, 2006 5:49 am
Your car is a: 1972 Fiat 124 Sport
Location: Winston-Salem, NC

Post by mdrburchette »

Oh Mark, those are not pictures to wake up to! :shock: Especially the one with all the dash wiring pulled out.
You can check the wiper motor with a car battery. I make little test wires with one end having a female connector, one for power and one for ground, attach the connector to the appropriate male connector and touch the other end of the wire to the pos and neg posts on a battery. With a wiper motor, find a wiring diagram to determine which connectors to use. Did you find one yet? Also, check the plastic wheel on the motor. these things eventually wear out. Here's a diagram that may help:

http://volcano.photobucket.com/albums/v ... wipers.jpg

copy it to you computer and open with paint so you can read it.

I'd also check the drain flaps on the firewall in the engine compartment to make sure they are clear of debris. It looks like they are clogged, causing standing water in the cowl, and hence, the rust.
Mark_vaughn

Post by Mark_vaughn »

Thanks for the diag. It helps. I think the short may be in the motor itself b/c I haven't found any obvious point that it could be on that circut yet. It got too dark to test much last night. But I got a long day of testing today.
Mark_vaughn

Post by Mark_vaughn »

I found the main short. It is in the wiper switch on the steering colum. I am trying to take the steering wheel off but am having trouble.

Anyone pulled one off recently? I am following the Haynes manual and I took the nut off, but it won't budge.

Any help?
So Cal Mark

Post by So Cal Mark »

put the nut back on, just a couple of threads. Brace your feet against the floorboard, grip the wheel on each side and pull like your life depended on it, alternating your effort from side to side on the wheel. If that doesn't do it, have an associate tap the top of the steering column using a hammer and brass punch while you pull on the wheel.

Just make sure you have put the nut back on to keep the wheel from coming completely off when it breaks loose
Mark_vaughn

Post by Mark_vaughn »

Thanks Mark.

I pulled and tapped with a hammer to the point that I thought I would break something. So I started testing again.

It turns out that my original thought was correct, I think. The wiper motor is the problem. I unhooked it and it stopped blowing the fuse. So it is either the motor or something that links back to the motor. To test the motor is it just the Red lead that is positive or both the red and black(I think)?

Progress has been made though. I found the under dash light and fixed a few grounds and wire spices. After I disconnected the motor I was able to get the heater blower to work. Also removed the coil and dampers to get them working properly.

I have a little rust repair to do then everything can go back together. I think I will go ahead and change the lights in the dash for some higher wattage and brighter lights.

One more Spider Grimlin killed!!
mdrburchette
Posts: 5754
Joined: Wed Jan 25, 2006 5:49 am
Your car is a: 1972 Fiat 124 Sport
Location: Winston-Salem, NC

Post by mdrburchette »

Mark_vaughn wrote:Thanks Mark.

One more Spider Grimlin killed!!
They have babies! :(
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