• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Electrical Problem?? Please Help!

  • Thread starter Thread starter DarkBlue302
  • Start date Start date Aug 21, 2009

DarkBlue302

New Member
Aug 19, 2009
6
0
0
Aug 21, 2009
#1
  • Aug 21, 2009
  • #1
I'm having an electrical problem and have no clue what it is. I'm a noob and still learning so please take it easy on me. Here is my problem, well one of them anyway lol.

So, I'll start from the beginning. My '93 LX 302 would start fine and run fine until one day, I would come out of work to leave and it would be dead. I'd need to jump it. Once I jumped it, I was fine. BUT it started to get worse and dying more frequently. So, one day I turned it off, went into work and forgot something so I came back out only a few minutes later. Well, when I got in my car, the radio was on! It was NOT on when I turned it off and there is no key in the ignition mind you. So, I was baffled. I put the key in, jiggled it (because the ignition switch/lock is messed up (bought it like that, haven't had the car that long). So after that it was fine. So I had to be real careful after that but only drove it a few more times until my front end problem started and had to stop driving it. I parked it. I had let the battery die again while it was parked so I just ended up buying a new one. But since it was parked, I just disconnected the new one so it wouldn't drain. Well it been a while and that battery ended up dying.

So since it was just sitting because I couldn't afford to fix the front end problem, I figured I'd just jump it next time I wanted to start to car. So just recently, I thought it's time to bring it back out and try to work on it (its a project). Well, I had to jump the battery of course. So I jumped it, it starts right up (never gives me a problem starting if there's juice) and let it run for a while because it has been sitting. But when I went to depress the clutch to put it in gear to move it, it dies! And will NOT start again unless it is jumped. I mean it dies completely, no light nothing. And it will die everytime. So it is currently not drivable at all.

I did some research and I think I narrowed it down to something electrical (yeah , I know not too narrowed but I'm a noob still). I know it could probably be several things but here are some things to consider:

Previous owner did all of this btw

gauge cluster was messed with (he went for the white faces, don't know exactly what he did though, whether the whole cluster was replace or not)
every gauge is either off or don't work
aftermarket radio was installed BUT I completely uninstalled it to replace it and there is currently NO radio
heater core is bad, antifreeze leaks of course BUT I made sure there was enough in there at the time.
I can tell there used to be additional gauges (one on the dash, a few on the door) but they were removed before I bought the car
he had some kind of neon lights installed because the switch that controlled them remains (its just disconnected)
there is a 'chip' that helps prevent theft that you must use in order to start it. which i have and it seems to work fine i guess

I tell you guys all this because it is all electrical related and may be contributing to the problem. So, what do you guys think?? I would so appreciate any help with this as I would love to get it 'drivable' again at minimal expense. I mean I was gonna start with the front end (horrible clunking, popping like sound; but that's a whole other thing) until this happened. So I'm open to anything I could possibly do myself. Sorry for the long post but I wanted to give as much info as possible to help.
Thanks a lot!
 

TechSteele

New Member
Mar 8, 2009
60
1
0
North Coast
Aug 21, 2009
#2
  • Aug 21, 2009
  • #2
Very first thing,
Replace the ignition switch.
It can cause all kinds of weird electrical problems.

After that, you have a pile of things you could check.
It sounds like you just need to do like I did, go through each and every system, piece by piece.
Sounds like you have alternator problems, negative problems, connections that are bad, nutral safety switch maybe, Dont know if that chip thing is involved. No idea why the battery died if it was disconected, unless that little bit of driving killed it that fast, and it was getting 0 juice back. Youll need to start it and check what if anything your getting back to the battery.

They had gauges in the door?
I thought the people before me messed mine up, sounds like your previous owner was a real winner too.
 

DarkBlue302

New Member
Aug 19, 2009
6
0
0
Aug 24, 2009
#3
  • Aug 24, 2009
  • #3
Thanks for your help. I think I will try the ignition switch first. I mean its can't hurt to ave a new one as I do think something may be wrong with it. I'll take your advice and go from there. I'll keep posted on the progress and when I fix it, I can help anyone else with the problem too. Thanks!
 
O

oh9mustang

Banned
Jul 27, 2008
138
0
0
Aug 24, 2009
#4
  • Aug 24, 2009
  • #4
ignition switch

ignition switch ground wire touching a hot someplace
 

DarkBlue302

New Member
Aug 19, 2009
6
0
0
Aug 24, 2009
#5
  • Aug 24, 2009
  • #5
I really want to replace that switch now and see. I think I'll pick on up today if I get a chance. But would that be causing it not to start back up again once it dies? Maybe the switch AND the alternator maybe? Thanks
 
O

oh9mustang

Banned
Jul 27, 2008
138
0
0
Aug 24, 2009
#6
  • Aug 24, 2009
  • #6
When you say "not to start", does that mean it does not turn over, or is it turning over just not starting?
 

DarkBlue302

New Member
Aug 19, 2009
6
0
0
Aug 24, 2009
#7
  • Aug 24, 2009
  • #7
Well, I mean I can jump it no problems and let it run for a few. But as soon as I press the clutch in to put it in gear, it dies completely. If I try to start it back up, it does absolutely nothing, not even a click. So then I have to give it another jump in order to start it back up. So "not to start up" is nothing at all, no turning over, no electrical. That's why I think it may be a combination of things because maybe the ignition switch AND the alternator is bad. Could any of this also cause the gauge cluster gauges not to function or be inaccurate?
 
O

oh9mustang

Banned
Jul 27, 2008
138
0
0
Aug 24, 2009
#8
  • Aug 24, 2009
  • #8
Next time you get it started , while its running, disconnect the positive cable from the battery, If the alternator is good it will continue to run, If not it will die. If it keeps running do not touch the positive cable to anything but the positive on the battery. Sounds like it could be several things, Bad Battery, Ignition switch, Alternator, Hot wire to ground, Ground wire touching a hot.
 

DarkBlue302

New Member
Aug 19, 2009
6
0
0
Aug 26, 2009
#9
  • Aug 26, 2009
  • #9
OK, so I bought a new ignition switch and replaced it. Didn't do anything. While I was replacing that, I figured since I had the panel and steering wheel trim off, I would just go ahead and remove the white gauge faces that the previous owner had put on. I didn't like them and they were wired up so I think they may have lit up or something. So removing those gave me a chance to remove some random wiring. I figured you never know, it could be contributing to the problem. But of course, it wasn't. So after replacing the switch and removing those, I jumped it again. It started right up. I let it run way longer this time to give the battery a chance to charge. And this time I didn't try pressing down the clutch to see if it stalls. Instead I first tested the alternator by removing the positive cable. That seemed fine because it continued to run fine. Then, I thought ok, I'll try to **** it off and restart it. I turned the key to off and I still had a working dome light unlike last time. But when I went to turn the key again, it died. With the steering wheel collar off, I examined the key cylinder/switch. I don't know what a normal one on this car looks like, but this one looked messed with and I don't think the key lock works right. So I was either thinking battery (even though its newer), battery cables (they look a little rough) or something with the actual ignition itself maybe. So here is where I'm at now.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Aug 26, 2009
#10
  • Aug 26, 2009
  • #10
Never disconnect a battery cable on a running EFI car. The voltage spike that results can wipe out electronics.

I don't know what was done exactly but be sure the battery connections are clean and tight (including at the solenoid), inspect the cables for rotting (they often rot from the inside out), be sure the motor grounds are up to par, and have the battery and alternator tested. I would also do a parasitic-draw test.
 

DarkBlue302

New Member
Aug 19, 2009
6
0
0
Aug 26, 2009
#11
  • Aug 26, 2009
  • #11
I keep hearing mixed answers about disconnecting the positive cable from the battery. Even my Dad has told me that but he is old school. Yeah, it's looking like it is not a good idea. Hopefully I didn't make things worse :/ I don't think so though. So I think I'm gonna take the battery in and have it checked. If it's bad then I should get a new one seeing as it is still under warranty. Then maybe I'll pick up some new cables too. I'm still wondering about that column/key cylinder though.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Aug 26, 2009
#12
  • Aug 26, 2009
  • #12
There's never a reason to disconnect a cable. There are other ways to test an alternator, and though it does not happen everytime, disconnecting the cable can fry electronics. In the old days of generators and before EFI and lots of electronics, disconnecting a cable was commonly done.
 

87GT40

New Member
Jan 20, 2007
59
0
0
virginia
Aug 26, 2009
#13
  • Aug 26, 2009
  • #13
it sounds like you definetely have a ground. it sounds like a trickle discharge effect.
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,811
234
Dublin GA
Aug 28, 2009
#14
  • Aug 28, 2009
  • #14
Auto Electrics 101: Generators will run without a battery. The iron core for the field coils will retain enough magnetism to create the magnetic field required to make electricity.

Alternators like the ones used on Mustangs require a battery to power the rotating field windings. That's because the AC current they generate internally demagnetizes the iron core for the field coils when there is no battery current to power them. The diodes inside the alternator turn the AC current into DC current. There are 3 phases to the alternator’s internal circuitry & 6 diodes to rectify the AC current into DC current. The battery acts like a big sink or capacitor to smooth out the remaining pulses

Never disconnect the battery from an alternator. The electrical spike produced before the alternator output drops to zero can damage things like the computer, radio and even the alternator itself.

There are some self exciting alternators, but I have never seen one on a Ford or GM car. The last self exciting alternator I worked on was a 200 amp 110 volt one in a Convar 580 twin turboprop airplane. That was over 30 years ago…


Troubleshooting current drains:
Typically it is something draining the battery. Small things like glove box or courtesy lights are often the culprits. If you have an aftermarket stereo or alarm system, it is also suspect.

The ideal method is to disconnect the negative terminal, and connect a Digital Multimeter (DVM) between the negative terminal on the battery and the negative cable. Set the DVM on a low current scale of 2-5 amps if it doesn't auto range. Watch the current draw, and then start pulling out fuses. When you see a sudden drop in the current, that circuit is the likely culprit. Note that the computer, radio & clock will draw less than 1/10 amp to keep the settings alive.

Using the negative side prevents nasty accidents like shorting the wrench to ground while disconnecting the battery cable. Electrically, the test will work with either positive or negative battery cable.
 
You must log in or register to reply here.

Similar threads

C
Electrical HELP! 1989 5.0 Stick, Voltage Bleed onto Ignition Trigger wire
  • ChickenDeluxe
  • May 14, 2026
  • Fox 5.0 Mustang Tech
Replies
7
Views
123
Fox 5.0 Mustang Tech May 24, 2026
ChickenDeluxe
C
M
2004 v8 convertible
  • Mikeycrownvicluver
  • Feb 12, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
11
Views
293
1996 - 2004 SN95 Mustang -General/Talk- Feb 15, 2026
Mikeycrownvicluver
M
L
Engine Why won't the motor start if I have spark and fuel
  • LeviAnderson
  • Nov 20, 2025
  • Fox 5.0 Mustang Tech
Replies
3
Views
365
Fox 5.0 Mustang Tech Nov 20, 2025
AeroCoupe
M
Engine Unexplainable Exhaust Pop and Gurgle
  • Mrnissen122
  • Feb 14, 2026
  • Fox 5.0 Mustang Tech
Replies
12
Views
457
Fox 5.0 Mustang Tech Feb 18, 2026
Noobz347
9
Electrical F150 ECU in a Foxbody? Idle surge help
  • 93royalblue
  • Sep 10, 2025
  • Fox 5.0 Mustang Tech
Replies
6
Views
376
Fox 5.0 Mustang Tech Sep 17, 2025
Mustang5L5
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?