Vintage Mustang Forums banner

1 - 5 of 5 Posts
G

·
Guest
Joined
·
0 Posts
Discussion Starter #1
I seem to have a problem with my elect. system somewhere that is causing all the lights inside and outside to flicker or pulsate slightly while the motor is running. I am relatively new at this classic car stuff so I am relying on someone with considerably more knowledge than myself to help. I put a volt meter on the battery and it reads 12v with motor off, the alternator is putting out the expected 13 volts. What I am not sure of is the location of the regulator, but I suspect it is built into the alt. Is this correct? Is there any other circuit that can be causing this on the light circuit? Also, it does seem to change frequency with engine rpm's. It also appears to be somewhat intermitent when I fidget with the light switch, but nothing that I can repeat with consistancy. I have noticed that is most evident when all lights (int/ext) are on (full load) while idling. I am suspecting a regulator but would like an expert opinion.
 

·
Premium Member
Joined
·
19,191 Posts
There's 2 basic places to look at. First (the cheapest!) is a loose fan/alternator belt. There should be less than 1/2" of deflection at the center point. Try tightening it up a bit. The second source is a faulty voltage regulator. The old style has a set of temperature-sensitive points/relay switch that might need adjustment (a royal PITA). Try replacing the VR. I've heard that Motorcraft makes a solid-state VR for the old 'stangs that is very good. Both are relatively cheap. The old style VR is located on the radiator support, driver's side, next to the radiator, interior engine compartment. Look for a squarish box with a bunch of wires going into it. It is grounded via a small wire that fits under one of the bolts: be sure the bolt hole area is free of paint, corrosion, and rust.

http://clubs.hemmings.com/baymustang/platesmall.jpgLet me check your shorts! My multimeter is just a-waiting! Formerly known as Midlife in the old VMF.
King of the Old Farts *struts*
 

·
Registered
Joined
·
6,163 Posts
Hi, I had a problem like that with my 67 and it turned out to be a rusty connection on the ground wire at the voltage regulator. John

Opal frost pearl metallic 67 coupe http://a1060.g.akamai.net/f/1060/597/30minutes/www.zing.com/picture/p1f4be09bbcbb2508dcabdaabc69f3080/febef75b.jpg
also have a 95 opal frost pearl G/T BOSS edition convertible belongs to swmbo
 
1 - 5 of 5 Posts
Top