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

Electrical 87 Electrical Mess

  • Thread starter Thread starter Southport2014
  • Start date Start date Nov 9, 2015
  • 1
  • 2
  • 3
  • 4
Next
1 of 4 Next Last
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 9, 2015
#1
  • Nov 9, 2015
  • #1
I have a 1987 mustang gt and am having major electrical problems.
Took the old harness out and out one that wasnt cut up. Got her running now just need to sort out some problems.
The turn signals will not work.
Only driver side window works.
Power locks do not work.
Ac/heat blower does not come on.
. Some one please help i meed to get this fixed asap.
I have some plugs not plugged in because I do not know where they plug into at.
Ill post pics maybe you can help.
 

Attachments

  • 20151109_161135.webp
    56.6 KB · Views: 225
  • 20151109_161117.webp
    60.1 KB · Views: 222
  • 20151109_161107.webp
    72.1 KB · Views: 222
  • 20151109_161052.webp
    31.8 KB · Views: 213
  • 20151109_161001.webp
    95.9 KB · Views: 200
  • 20151109_160954.webp
    71.9 KB · Views: 233
  • 20151109_160929_001.webp
    68.5 KB · Views: 175
  • 20151109_160906.webp
    98 KB · Views: 203
  • 20151109_160834.webp
    49.5 KB · Views: 206
  • 20151109_160744.webp
    82.2 KB · Views: 182
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 9, 2015
#2
  • Nov 9, 2015
  • #2
Got the windows and locks to work. Just need to figure out turn signals and ac blower
 
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 10, 2015
#3
  • Nov 10, 2015
  • #3
Would this cause my turn signals and ac blower not to work ?
 

Attachments

  • 20151109_152209.webp
    65.8 KB · Views: 209

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Nov 10, 2015
#4
  • Nov 10, 2015
  • #4
Southport2014 said:
Would this cause my turn signals and ac blower not to work ?
Click to expand...

@madmike1157 Please merge this guy's multiple threads together into one thread.

@Southport2014

It is the ignition switch wiring connector. The power for everything that needs the ignition switch to be in the Run position goes through it. That includes the turn signals and A/C blower. The Ignition switch is also suspect.

Diagrams courtesy of Tmoss & Stang&2birds

Ignition switch wiring


Some of the symptoms of ignition switch problems are things that don’t work or are intermittent like radio, turn signals, wipers or heater. The auto parts stores sell the switches for $13-$15.







While you are working on the switch, check the wiring and connector closely. A replacement connector with new wiring pigtails is available from most auto parts stores

AutoZone and Advanced Auto Parts have the same Part Number: 434 - may have to order, not always in stock

Advanced Auto Parts alternate part number: PT5534



If just the plastic shell is broken, a small jewelers screwdriver inserted from the front will release the contacts from the connector shell. Do this one wire at time and insert the wire and connector you removed into the same position on the replacement connector shell.

Saleen0679 was nice enough to dig this up for us awhile back: Replace a 1979-1993 Ignition Switch Assembly

Torx bit set from Advance Auto Parts



Autocraft torx bit set – have small hole in tip for tamper proof screws.
Part No. AC571/W1386 Cost approx. $12 +tax


You really need to look at the links I posted. to Mustang FAQ - Wiring & Engine Info If you did, you would have figure all this out very quickly. I will post the links one more time. I will politely tell you to look at them before you make another post. I am not here to spoon feed answers to people, but to give them tools to enable the to do the task at hand and to help them think about what they see, hear and feel. In other words, observe, think about what you observed and diagnose!

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring Mustang FAQ - Wiring & Engine Info Everyone should bookmark this site.

94-95 Mustang wiring diagrams
Mustang FAQ - Wiring & Engine Info

Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

O2 sensor wiring harness
http://www.veryuseful.com/mustang/tech/engine/images/mustangO2Harness.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pin out
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif

Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

Mustang 5.0 Lights and Radio schematic, by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxLights-Radio_diag.gif

87-92 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang87-92 PowerWindowWiring.gif

93 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang93PowerWindows.gif

T5 Cutaway showing T5 internal parts
http://www.veryuseful.com/mustang/tech/engine/images/5_Speed_Cutaway_Illustrated.jpg

Visual comparison of the Ford Fuel Injectors, picture by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/Ford_Injector_Guide.jpg

Convertible top motor wiring http://www.veryuseful.com/mustang/tech/engine/images/mustang88VertTopMotorCkt.gif

Engine mounted fuel injector harness
http://www.veryuseful.com/mustang/tech/engine/images/mustangEngineHarness.gif tang/tech/engine/images/mustang88VertTopMotorCkt.gif
 
Last edited: Nov 11, 2015
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 11, 2015
#5
  • Nov 11, 2015
  • #5
Ok ive looked at the links. I replaced the ignition swotch6. I have replaced the part that plugs onto the ignition switch. I have checked all fuses and all relays. What do you think i need to do next. Now my drover side brake loght os very dim.
 
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 12, 2015
#6
  • Nov 12, 2015
  • #6
Brake light problem and ac blower r working . Jusy need yo figure turns out
 
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 13, 2015
#7
  • Nov 13, 2015
  • #7
Is this supposed to be kind of loose
 

Attachments

  • 20151113_174717.webp
    57.4 KB · Views: 170

90sickfox

Wasn't a pretty sight...and I've got big hands
SN Certified Technician
Mar 2, 2015
6,945
5,816
213
Nov 13, 2015
#8
  • Nov 13, 2015
  • #8
Kind of loose....its the cancel for the turn signals. I had funny things happen with turn signal switches. If you put the lever in right or left turn position that button should make it pop back to center.
 
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 13, 2015
#9
  • Nov 13, 2015
  • #9
Ive tried everything trying tovget my signals to work and this may be the problem idk.
 
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 14, 2015
#10
  • Nov 14, 2015
  • #10
When i tested the wores leading into the turn signal plug switch only one had power and it was the blue with orange
 

90sickfox

Wasn't a pretty sight...and I've got big hands
SN Certified Technician
Mar 2, 2015
6,945
5,816
213
Nov 14, 2015
#11
  • Nov 14, 2015
  • #11
Dark blue and orange is the power feed into the turn signal switch...there should be a light blue and a white w/red stipe wire running to the hazard light part of the switch. The solid light blue is for the turn signal flasher ( fuse 5 ) the white w/red is for the hazard flasher ( fuse 1 ) orange w/yellow stripe should be the out put for the turn signal light bulbs. So the complete turn signal circuit is fuse 5 15amp from fuse box ( pink/orange) to turn signal flasher.....from flasher ( light blue) to hazard part of multifunction switch to (orange w/yellow) out from hazard function to the turn signal part of switch where it out puts to all the turn signal lights. Fuses 10, 5, and 1 should all have power whether key is switched on or not.
 
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 18, 2015
#12
  • Nov 18, 2015
  • #12
I do not have power to fuse 5 when key is off but when on i have power to it. Fuse 1 and 10 have power for both
 
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 18, 2015
#13
  • Nov 18, 2015
  • #13
And do you mean purple orange from fuse box
 
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 18, 2015
#14
  • Nov 18, 2015
  • #14
On the flasher I only have power on the orang purple wire to the flasher. Thr light vluebwore has no power
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Nov 18, 2015
#15
  • Nov 18, 2015
  • #15
Southport2014 said:
On the flasher I only have power on the orang purple wire to the flasher. Thr light vluebwore has no power
Click to expand...
Are you using a mobile device (AKA smartphone or tablet) to make your posts?
 
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 18, 2015
#16
  • Nov 18, 2015
  • #16
Yea sorry the auto correct is mental. I have power from the orange and purple wire to the relay. The light blue wire has no power
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Nov 19, 2015
#17
  • Nov 19, 2015
  • #17
Southport2014 said:
On the flasher I only have power on the orang purple wire to the flasher. Thr light vluebwore has no power
Click to expand...
Locate the turn signal flasher, keep in mind that the flasher on the front of the fuse panel is for the hazard flasher. Once you have located the turn signal flasher, remove it from its socket and jumper the socket contacts together. Turn the ignition switch to Run and try the turn signals. They should come on steady if you have good 12 volts to the orange/purple wire.
 
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 19, 2015
#18
  • Nov 19, 2015
  • #18
Ok i will try this when i get home.
 
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 19, 2015
#19
  • Nov 19, 2015
  • #19
No lights came on. Tried my test light on both wores and got no power.
 
S

Southport2014

Member
Jan 28, 2014
200
4
19
Nov 20, 2015
#20
  • Nov 20, 2015
  • #20
And suggestions?
 
  • 1
  • 2
  • 3
  • 4
Next
1 of 4 Next Last
You must log in or register to reply here.

Similar threads

1
Electrical Headlight harness trouble
  • 1985fox
  • Apr 14, 2026
  • Fox 5.0 Mustang Tech
Replies
7
Views
228
Fox 5.0 Mustang Tech Apr 17, 2026
AeroCoupe
1
Electrical 1985 mustang gt Led conversion trouble
  • 1985fox
  • Jan 5, 2026
  • Fox 5.0 Mustang Tech
Replies
10
Views
607
Fox 5.0 Mustang Tech Jan 15, 2026
1985fox
1
R
electrical plug identification
  • redlineracing1328
  • Jun 11, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
1
Views
96
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jun 12, 2026
keel
Door wire harnesses 1996 GT
  • Adizzle843
  • Feb 5, 2026
  • SN95 4.6L Mustang Tech
Replies
7
Views
352
SN95 4.6L Mustang Tech Feb 17, 2026
Adizzle843
F
Electrical Foxbody wiring harness 2.3 to v8 swap
  • Foxbodyjake
  • Mar 23, 2026
  • Fox 5.0 Mustang Tech
  • 2
Replies
24
Views
677
Fox 5.0 Mustang Tech Apr 13, 2026
Foxbodyjake
F
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?