Struck down by the electrical gremlins - Page 2 - Vintage Mustang Forums
 7Likes
Reply
 
Thread Tools
post #16 of 25 (permalink) Old 08-16-2018, 02:12 AM Thread Starter
Senior Member
 
kiwinz's Avatar
 
Join Date: Feb 2016
Location: Portland OR
Posts: 118
Well, its time for an update. Wait for it - I found a doozie!

The electrical issue stumped me and after several hours looking for the issue and trying to narrow it down, and needed to walk away for a while (work travel came up) and I didn't get back to it until today. Its been sitting in the garage in pieces with all the nice weather of summer going by. So I looked at in more detail, and realized its an American Autowire set thats in it. I pulled the seat and as much out of the way to look into it (so wish the clutch and brake pedal assemblies were out of the way). Narrowed down the issue was under the dash or forward, but pretty much had to expose all the wires exposed. I almost couldn't remember the initial problem, other than the rear tail lights stopped working and i found the fog light fuse was an issue (grounded short on one side). To make it a short story, I ended up unwrapping the wiring harness from the fuse panel onwards to trace an orange un-marked wire that came from the grounded side of the fuse panel (on the back). I found it went to the ground on the cigarette lighter??!!?? WTF? So I guess the fuse has been blown since the day I got it, and has nothing to do with the rear tail lights not working initially (which could be something simple). I downloaded the AWW wring instructions and they were awesome to call me today to try and help me out, but without wiring schematics - Id never have traced the orange wire without physically following it. How the PO put it on the ground of the cig lighter I have no idea. It was all wrapped in the back fabric tape - so you can imagine how difficult it was to unwrap and find where that wire went. I have no idea where the orange wire is meant to go, or if it came with the AWW set (although its attached like factory to the back of the panel). I took some photos but they all look like nothing - just a bunch of wires. Heres one though with the orange are and the end I pulled from the cig lighter.

So tomorrow - I'm hoping I remember how it all goes back together and can get the car started. Lots of things to put back together, including all the lights and the instrument bezel. And then try to find out whats up with lights (excluding a fuse issue).....
Attached Images
File Type: jpg IMG_8401.JPG (91.4 KB, 7 views)
kiwinz is offline  
Sponsored Links
Advertisement
 
post #17 of 25 (permalink) Old 08-16-2018, 04:57 PM
Senior Member
 
Join Date: Mar 2018
Location: Denver(ish)
Posts: 729
Well, the fuse panel should tell you what that wire is for. What fuse is it? It may be that it's for the lighter, but the PO just didn't know which was positive and which was ground. Now that you have that figured out, it's time to chase your 12v+.
1) 12v into brake light switch?
2) out?
3) Where's it go next?
4)...
jgrote is offline  
post #18 of 25 (permalink) Old 08-16-2018, 06:34 PM Thread Starter
Senior Member
 
kiwinz's Avatar
 
Join Date: Feb 2016
Location: Portland OR
Posts: 118
jgrote; the fuse is from the fog light fuse. It goes no where as this is the wire directly from the back of the fuse panel (with power coming to the other side of the fuse). So it had nothing to do with my parking light / tail lights not working. So now I need to solve why I do not have park lights or tail lights. I do get headlights and turn signals both front and back.

Any one have any ideas on where to check? Perhaps how to check my headlight switch is working correctly? I do not have any blown fuses but I'll check again. Also with the American Autowire set up, which fuse controls all the lights? I thought it must have been the circuit labeled Fog Lights as it was the only option. Of course its not now that I learnt it goes no where. As a reminder - all lights worked correctly until one day after driving it.
kiwinz is offline  
 
post #19 of 25 (permalink) Old 08-16-2018, 06:39 PM
Senior Member
 
Join Date: Mar 2001
Location: Tunkhannock PA
Posts: 19,689
Quote:
Originally Posted by jgrote View Post
Alright, Here's how I see your situation. You have been troubleshooting from all angles at once. Therefore, you're chasing your tail. I'm a service tech by trade, but not on cars. But here is how I'd go about it in this case.
1) Choose one end or the other to start at. (Bulb or battery)
2) Chase your voltage (or ground) toward the other end.
3) You'll find it!

Now if I were to guess where your problem is from my couch, it's behind your fuse box. Pull it out and see if anything sticks out. But I have a few questions first.

1) Do you have 12v on one side of the fuse slot with the fuse out?
If so, I'd guess that everything from the battery to the fuse box is okay.
2) Is the other side of the fuse slot grounded?
If so, then it's time to start chasing that wire. I assume it goes fuse-->brake light switch-->bulb. The tail light wire should come from the headlight switch.
3) Are the tail and brake lights on the same fuse? If so, and both headlight and brake light switches are good, then the issue is between the fuse box and those switches.

I guess what I'm getting at is this. You need to break the circuit down into smaller sections. Check those sections, and find out if they are healthy. I like to use any place something unplugs to isolate sections. For instance, if you unplug the wires at the brake light switch, is the load side of the fuse slot still grounded? If so, your issue is now between the fuse and the brake light switch plug. If not, it's after that. Then just keep working your way back.

For now, have a beer. Tomorrow, have a plan! If you want to talk it through, PM me your # and I'll be happy to give you my opinion on things.

This ^^^^ I'm a electrician by trade. One of the first things is to have a basic understanding of what you're doing. Quick electrical tutorial 101. In a series circuit you add up all the resistance and divide that into voltage. This gives you the amperage through everything. All will have the same amperage. Amperage times Resistance gives voltage. So a quick recap, everything will have the same amperage. the voltages of each component add up to the battery voltage. What ever has the most resistance drops the most voltage meaning you'll read the highest voltage. A volt meter has a extremely high resistance. So high that everything else is like a copper wire in comparison which means you're going to be basically be reading the battery voltage. Keep this in mind as to why you can be reading the battery voltage when you think you should be reading something else. This can be why you may think you have a short circuit when you read 12 volts.

Go back and look at everything you touched before you had problems, even if you thing it's totally unrelated. Those totally unrelated tend to be the problems. Chase 1 problem at a time and divide and concur as jgrote said.

Tom

One thing great about getting older. A life in prison sentence is less of a deterrence

Huskinhano is offline  
post #20 of 25 (permalink) Old 08-16-2018, 06:42 PM Thread Starter
Senior Member
 
kiwinz's Avatar
 
Join Date: Feb 2016
Location: Portland OR
Posts: 118
Quote:
Originally Posted by Huskinhano View Post
This ^^^^ I'm a electrician by trade. One of the first things is to have a basic understanding of what you're doing. Quick electrical tutorial 101. In a series circuit you add up all the resistance and divide that into voltage. This gives you the amperage through everything. All will have the same amperage. Amperage times Resistance gives voltage. So a quick recap, everything will have the same amperage. the voltages of each component add up to the battery voltage. What ever has the most resistance drops the most voltage meaning you'll read the highest voltage. A volt meter has a extremely high resistance. So high that everything else is like a copper wire in comparison which means you're going to be basically be reading the battery voltage. Keep this in mind as to why you can be reading the battery voltage when you think you should be reading something else. This can be why you may think you have a short circuit when you read 12 volts.

Go back and look at everything you touched before you had problems, even if you thing it's totally unrelated. Those totally unrelated tend to be the problems. Chase 1 problem at a time and divide and concur as jgrote said.
I'm trying....
kiwinz is offline  
post #21 of 25 (permalink) Old 08-16-2018, 08:50 PM
Senior Member
Supporting Member
 
gordonr's Avatar
 
Join Date: Oct 2015
Location: Virginia Beach
Posts: 432
Congrats on your find. Looks like a chevy man had his hands in there at one time by the orange wire color choice for the lighter.

1969 Mach 1 S code...2nd owner
gordonr is offline  
post #22 of 25 (permalink) Old 08-16-2018, 10:44 PM
Just some guy
Supporting Member
 
GypsyR's Avatar
 
Join Date: Jun 2001
Location: SC foothills, USA
Posts: 18,981
Garage
Quote:
Originally Posted by kiwinz View Post
I'm trying....
Excellent! Keep that up. Report back with your wins or dead ends. Wiring is tough. Trying to sort out some aftermarket wiring that who knows who was all into is way up on the difficulty scale. Just how it is. Focus on a little at a time, it's fixable.
GypsyR is offline  
post #23 of 25 (permalink) Old 08-16-2018, 11:06 PM Thread Starter
Senior Member
 
kiwinz's Avatar
 
Join Date: Feb 2016
Location: Portland OR
Posts: 118
Solved!! Its the headlight switch. What an experience. Ended up having the car non drivable for too much of this season. Good news is I found a crazy miss-wire. I don't have fog lights so never noticed the miss-wire and blown fuse until I had the issue with the lights. I figured it was a fuse and it must have been the fog lights as there was no other light fuse - and now I know its all in the headlight switch! I also cleaned up all the wiring and wrapped it with the wire wrap and protected it on any sharp edge (going into the drivers kick panel). I still need to go back out and put the bezel back in and the light lens's back on. Might be able to drive it tomorrow....

I had brake lights and turn signals working, so just tail lights and park lights were the issue. I started at each corner checking bulbs, then wiring (the power probe is so useful for this), and ended up at the switch. The light switch was solved by searching for the wiring diagram and checking continuity between the points on it (found the info on VM of course). If I slightly move the switch in and out from its middle or fully out position - I actually get the lights to work! What a sign of relief. Although now to order a new switch so I don't have to fiddle and worry they are not working. I might have solved this the day I had the issue and saved all this time if I'd fiddled with it and been able to see the lights come on and off. Best idea I found today in searching how to videos - using a large mirror in front and back of the car to see whats happening!!

Thanks to all who helped with their responses. Although no one turned up with the beer...
kiwinz is offline  
post #24 of 25 (permalink) Old 08-16-2018, 11:11 PM Thread Starter
Senior Member
 
kiwinz's Avatar
 
Join Date: Feb 2016
Location: Portland OR
Posts: 118
Quote:
Originally Posted by gordonr View Post
Congrats on your find. Looks like a chevy man had his hands in there at one time by the orange wire color choice for the lighter.
I think AWW uses chevy parts for their rewire kits. Perhaps the fuse panel, and definitely the connection for the steering column wiring. They label their wires, but they can be hard to read when its been installed already and much of it covered or rubbed a little. The orange wire from the back of the fuse panel had no label on it - so I have no idea where that is actually meant to go. Strange that it has a connection on it and no matching home is there. I don't need it so I'll wrap it up into I decide to add fog lights perhaps. They have great install instructions available, but no real wiring diagram or fuse panel schematic so troubleshooting was a little tough. That may just be because its me. Ive got lots of wiring experience for the basics but not that great with a multi meter for advanced stuff.
kiwinz is offline  
post #25 of 25 (permalink) Old 08-16-2018, 11:15 PM Thread Starter
Senior Member
 
kiwinz's Avatar
 
Join Date: Feb 2016
Location: Portland OR
Posts: 118
Quote:
Originally Posted by GypsyR View Post
Excellent! Keep that up. Report back with your wins or dead ends. Wiring is tough. Trying to sort out some aftermarket wiring that who knows who was all into is way up on the difficulty scale. Just how it is. Focus on a little at a time, it's fixable.
thanks Gypsy! I got it solved. I always appreciate when you chime in with help and encouragement. At least I didn't need to patch 3 old wire harnesses together, that must have been a challenge.
kiwinz is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Vintage Mustang Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome