• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-

Electrical issue please help

  • Thread starter Thread starter Michaelchris516
  • Start date Start date Jan 8, 2020
M

Michaelchris516

New Member
Jan 8, 2020
2
0
1
Nebraska
Jan 8, 2020
#1
  • Jan 8, 2020
  • #1
I have a 2001 mustang GT 5 spd that I bought in rough condition that I’ve been restoring, car currently has 99k miles. I rebuilt the motor and put a new ECU in it because I was told it had a v6 ecu in it by a local ford dealership (I think the guy was lying to me) when I was diagnosing a misfire issue. (Timing was off, that was the actual reason) had the new ecu flashed to my car by a different dealership. Car ran and drove great, ever since I’ve owned the car, even with the bad engine and odd ball ecu the car has has had a parasitic draw and has now ruined 2 batteries from boiling them (overcharging I assume) so I put a new alternator on and the problem stopped for a couple days. Now it does it again. Haven’t driven the car much in many months because I don’t want to keep ruining 100$ batteries. I’ve owned the car for 3 years now and I just want to drive it. Also sometimes the cluster will do some weird things. Odometer will temporarily shut off while driving then randomly come back on. Any tips would be amazing!
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Jan 8, 2020
#2
  • Jan 8, 2020
  • #2
If this were my car I would focus on the battery negative ground and the grounds to the radiator core support and the motor ground. Make DOUBLE certain that all of the grounds are solid, clean, and tight. Need to be capable of carrying heavy currents with little (or no) voltage drop.

Double check that the motor grounding strap between the left hand motor mount and the car's frame rail is in place.

What is the voltage at the battery? It shouldn't be a mystery if the battery is being over charged or under charged.

Here's some information that should help.

Howto perform charging system voltage drop test

Howto perform charging system voltage drop test

To anyone else reading any of my posts I usually include the line: Today's cars simply will not run right without a strong battery and charging system! Cut corners here at your own risk I'm a big believer in starting with the basics. As such I...
www.stangnet.com

My odometer goes on and off?

My odometer goes on and off?

I've notice that my odometer on my '02 mustang has been going on and off at anytime. I started to see this when my car reached 90K. I also have a '99 F-150 that stared when it reached 90K also now has 102k. Has anyone else had this problem with any mustangs out there?:headscratch:
www.allfordmustangs.com
 
Reactions: Michaelchris516

kiddiccarus

The first widely accepted Tranny
20+ Year Stangneter
Dec 24, 2003
1,789
1,051
143
30 Mins from a Ragged GT
Jan 9, 2020
#3
  • Jan 9, 2020
  • #3
^^ Agree ^^ I had a constant draw on my 95v6 and if i didnt drive it 2x a week the battery would be dead in 4 days. So I chased the demon down to the ground wire to the body, rust and debris formed in between the semi loose connection and once I cleaned it and tightened it up, the issue was gone.
 
Reactions: Michaelchris516
M

Michaelchris516

New Member
Jan 8, 2020
2
0
1
Nebraska
Jan 10, 2020
#4
  • Jan 10, 2020
  • #4
Thank you guys so much for the quick replies, sure enough I checked my ground and it was corroded on the connection to the chassis. I never had it off when I pulled the motor. Put a different known good battery in it and it didn’t drain over night and I’ve put ~100 miles on it between yesterday and today and it didn’t boil the battery yet. Charging at idle about 14.5-14.7 When I first got the ground fixed and fired it up
 
You must log in or register to reply here.

Similar threads

A
Resolved Electrical Help Please
  • Alabama
  • Jan 22, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
2
Views
237
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 22, 2026
AeroCoupe
A
1987 5.0 speed density Foxbody crank no start
  • Alan2204
  • May 23, 2026
  • Fox 5.0 Mustang Tech
Replies
10
Views
121
Fox 5.0 Mustang Tech May 30, 2026
Mcmahst
S
Car shakes when taking off help???
  • STANKYstangs
  • May 10, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
12
Views
169
1996 - 2004 SN95 Mustang -General/Talk- May 27, 2026
LILCBRA
2
Electrical mayhem
  • 2000ElectricGreen
  • Mar 13, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
2
Views
201
1996 - 2004 SN95 Mustang -General/Talk- Mar 24, 2026
2000ElectricGreen
2
S
Fox '87 GT can't get to stay running
  • spilly
  • Mar 29, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
26
Views
561
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 25, 2026
CAMTWO1070
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
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?