• Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-

1966 Mustang GT - Courtesy/Interior Light issue

  • Thread starter Thread starter Veneratio
  • Start date Start date Jun 11, 2022
V

Veneratio

Member
May 23, 2021
5
2
13
Michigan
Jun 11, 2022
#1
  • Jun 11, 2022
  • #1
Hi, everyone. I have posted a couple times before and you have been a tremendous help.
My latest problem is my Courtesy/Interior lights will not come on. This is what I have done:
I replaced all the bulbs, door switches, headlight switch etc. I checked continuity of the wiring, I double checked all the grounds - all seems good. I pulled the fuse box, everything is clean and seems good. But I cleaned and replaced all the fuses and the connectors anyway. I have not replaced the wiring harness - trying to avoid that. I mean as you all know a lot of work.
Now if I give 12V power to the Black/Blue wire #53 on the headlight switch plug - all the lights come on without regard to the position of the door switches.
I can not figure out why the courtesy/interior lights do not seem to get power without the external 12v power source.
Any suggestions/ideas etc would be very much appreciated. Super frustrated right now - been working on it for several weeks.
Thanks
 
V

Veneratio

Member
May 23, 2021
5
2
13
Michigan
Jun 15, 2022
#2
  • Jun 15, 2022
  • #2
Hey Guys, I located the issue. Some time ago, someone installed an in line fuse in the Grn/Yel line. I located the fuse, although it tested good, I replaced it and everything works like it should now. This had me stumped, but feeling good now. Just wanted to let everyone know how this issue was resolved. Thanks
 
Reactions: 2Blue2 and COramprat

COramprat

...I can take it. I think.
20+ Year Stangneter
Mar 2, 2003
8,474
1,463
223
Sea of Tranquility
Jun 15, 2022
#3
  • Jun 15, 2022
  • #3
Electrical issues are hard to diagnose. So many factors that lead to issues. Cool you got it fixed.
 
You must log in or register to reply here.

Similar threads

J
67 mustang interior courtesy light wiring
  • JCuster
  • Jun 9, 2026
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
2
Views
87
1965 - 1973 Classic Mustangs -General/Talk- Jun 17, 2026
GypsyR
G
S
Electrical No dash lights
  • slojoexxx
  • Dec 11, 2025
  • 1994 - 1995 Specific Tech
Replies
0
Views
151
1994 - 1995 Specific Tech Dec 11, 2025
slojoexxx
S
2
Electrical mayhem
  • 2000ElectricGreen
  • Mar 13, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
2
Views
276
1996 - 2004 SN95 Mustang -General/Talk- Mar 24, 2026
2000ElectricGreen
2
M
Need help!
  • Masonevans726
  • Dec 17, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
242
1996 - 2004 SN95 Mustang -General/Talk- Dec 17, 2025
Masonevans726
M
2
SJB Parasitic Draw, Fuse 59&67
  • 2005 Mustang V6
  • Apr 30, 2026
  • 2005 - 2014 S-197 Mustang -General/Talk-
Replies
0
Views
101
2005 - 2014 S-197 Mustang -General/Talk- Apr 30, 2026
2005 Mustang V6
2
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1965 - 1973 Classic Mustangs -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?