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

Headlights/Interior Lights Pulsing

  • Thread starter Thread starter 67_Vert
  • Start date Start date Apr 29, 2007

67_Vert

New Member
Apr 29, 2007
5
0
0
Apr 29, 2007
#1
  • Apr 29, 2007
  • #1
Greetings all!

I just picked up a 67 convertible, fully resto'd and really the only thing I can find wrong with it is that the headlights and interior lights pulse when you bring the RPMs up a little. Any ideas on what might cause this? Alternator?

Thanks in advance!

BTW, you can see pics here if you want:

http://picasaweb.google.com/bdillon08/Mustang
 

Rusty67

20+ Year Stangneter
Dec 3, 2002
3,749
37
109
LA, CA
Apr 29, 2007
#2
  • Apr 29, 2007
  • #2
Could be a couple of things. If you can check the voltage at the battery while it happens that would tell you if its the alternator. Just have a friend rev it for you. Also, it could be that the headlight switch itself is going bad and the vibration from the engine is causing it to short intermitently.
 
T

TOM B

20+ Year Stangneter
Nov 15, 2002
872
1
16
Harrisburg Pa
May 1, 2007
#3
  • May 1, 2007
  • #3
Most if not all older mustangs will do this because of the low 60 amp alternator and regulator, upgrade to a one wire 100 amp alternator and get rid of all your troubles.
 
T

tretz

Member
Mar 17, 2004
62
0
6
stockton, ca
May 1, 2007
#4
  • May 1, 2007
  • #4
cured mine with a new light switch
 

65fastbackresto

Active Member
Apr 13, 2007
1,229
7
39
AR
May 2, 2007
#5
  • May 2, 2007
  • #5
Mine does it too

I thought it was normal....
 
6

66HertzClone

New Member
Aug 24, 2004
428
0
0
Central New Jersey
May 2, 2007
#6
  • May 2, 2007
  • #6
Look for the ground strap between the rear of the right side cylinder head and the firewall. Often missing, this pesky little thing can cause the symptoms you describe, to make sure the strap will help, place a jumper cable between the block and a hefty bolt on the chassis. The original point type style voltage regulator can sometimes cause this, a new replacement using an electronic style is a good inexpensive improvement.
 
J

justford

Founding Member
Feb 15, 2001
66
0
7
Grayson KY
May 7, 2007
#7
  • May 7, 2007
  • #7
The electronic voltage regulator cured my problems with the lights.
 

67_Vert

New Member
Apr 29, 2007
5
0
0
May 11, 2007
#8
  • May 11, 2007
  • #8
justford said:
The electronic voltage regulator cured my problems with the lights.
Click to expand...

Which one did you use?

My switch is also bad, the potentiometer doesn't seem to work. As I turn it to the right to dim the interior lights, the lights flicker on and off.

I will replace both, I just need a recommendation on which voltage regulator to use.
 
F

ForceFed70

That's why they call it "dope"
Founding Member
Dec 6, 1999
4,818
1
69
BC Canada
May 11, 2007
#9
  • May 11, 2007
  • #9
My car did the same thing. It was either the voltage regulator or the alternator, I replaced both and it fixed my problem. It had nothing to do with the alternator being too small....
 
You must log in or register to reply here.

Similar threads

2
Resolved Electrical mayhem
  • 2000ElectricGreen
  • Mar 13, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
3
Views
354
1996 - 2004 SN95 Mustang -General/Talk- Sep 4, 2026
2000ElectricGreen
2
What's it Worth? 2000 GT
  • Mustang5L5
  • May 8, 2026
  • What is it Worth?!?!?
Replies
6
Views
384
What is it Worth?!?!? Jun 13, 2026
KRUISR
S
Preparation for Holley Terminator X install – Foxbody 306 (electrical fan, alternator, MSD Ignition, etc)
  • So_Flo
  • Mar 1, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
22
Views
2K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Mar 4, 2026
General karthief
Resolved Gauges and lights pulsing
  • sav22rem22
  • Sep 25, 2023
  • Fox 5.0 Mustang Tech
Replies
13
Views
4K
Fox 5.0 Mustang Tech Oct 23, 2023
sav22rem22
97 Cobra Bank 2 Running Rich
  • 91LX302
  • May 29, 2023
  • SN95 4.6L Mustang Tech
Replies
1
Views
2K
SN95 4.6L Mustang Tech Jun 1, 2023
91LX302
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific 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?