Whats wrong wiht my electrical system?

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natejones75

New Member

Oct 21, 2003

58

0

0

Evansville, IN

Apr 5, 2004

#1

• Apr 5, 2004

• #1

i think I have an electrical issue with my 65 fastback. When as idel, my interior lights go dim and fluctuate with the idle. I also have a blown a low beam headlight out twice in the last 2 years, and when they are both on on high beam, they cut out after awhile. I hve already replaced the voltage regulator, and the dimmer switch. Is this somehting as simple as a faulty alternator? Any advice? Could this effect the performance of the motor by hindering the ignition? natejones75@hotmail.com

 

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stang-69

New Member

Jun 5, 2003

25

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0

Sweden

Apr 5, 2004

#2

• Apr 5, 2004

• #2

It´s quite easy to check the alternator, simply check the voltage over + and - on the battery when engine is idling. I don´t realy know how much the regulator gives (I´m running a Bosch alternator with built in regulator), but i should read approx 12.7V

 

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slapper

Founding Member

Mar 6, 2002

447

0

0

Apr 5, 2004

#3

• Apr 5, 2004

• #3

Check the high beam switch on the floor. Getting hot?? Loose wire connector??
If I remember correctly, power is routed through the floor dimmer switch, then to the headlight switch???

 

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Ronstang

New Member

Apr 4, 2004

1,294

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0

Houston Texas

Apr 5, 2004

#4

• Apr 5, 2004

• #4

Ah, remembering the good old days. Your problem is more than likely the voltage regulator, especially if you are running an original/original style mechanical regulator. My older Mustang's used to always do this also until I switched to using the later model (late 70's) solid state external regulators.

Bump up your idle a little and see if it goes away. Sometimes the idle is set way to low for the alternator/voltage regulator to give a good constant voltage.....but still get a new solid state regulator or upgrade to a newer internally regulated alternator.

 

6

'69Mach1Chick

There's no grass left to cut.

Apr 1, 2002

348

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0

North Jersey

Apr 5, 2004

#5

• Apr 5, 2004

• #5

yeah make sure you clean and check the plug under the carpet where you switch on the highbeams....my solution...i don't use highbeams anymore

 

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natejones75

New Member

Oct 21, 2003

58

0

0

Evansville, IN

Apr 5, 2004

#6

• Apr 5, 2004

• #6

Now what?

As in my first letter, I have replaced both the dimmer switch and the voltage regulator. I want a voltage regulator to keep original appearances, but how do you wire in a later version solid state unit? Is it the same wiring harness?
If I was going to buy one at Autozone or somewhere, what model voltage regulator (off of what year and car) would I ask for?

 

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Ronstang

New Member

Apr 4, 2004

1,294

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0

Houston Texas

Apr 5, 2004

#7

• Apr 5, 2004

• #7

The later model solid state one looks almost identicla but it is about half as thick since there are no mechanical parts under the cover. The simple solution is to remove the cover off of yours.....drill out the rivets on the solid state one, and simply use your cover. The plug is the same on both so it is a direct replacement part.

 

mustang70

Founding Member

Nov 15, 2001

2,445

2

48

San Diego

Apr 5, 2004

#8

• Apr 5, 2004

• #8

Do you have halogen headlights by chance?

 

Swede958

Founding Member

Dec 17, 2001

712

0

0

Austin, TX

Apr 5, 2004

#9

• Apr 5, 2004

• #9

Later model, '70, regulator is pn VR749 if memory serves me right. (Autozone parts monkey). Look up one for a '70 stang and you get like three choices. About 9$ I believe.

As for the charging- if your car runs take it to autozone and have them check it out. It'll tell you charging amps at idle and with a load on.

For the lights, feel underneath to the headlight switch- see if that's getting hot at all. If it gets too hot- replace it. Especially if you have halogen lights. I used one from a 67 Couger, just had to modify the mounting cup a little.

Hope it helps,
THe swede

 

KillerKittyCat

New Member

Aug 24, 2003

150

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0

Hammer Down - Behind The Wheel

Apr 5, 2004

#10

• Apr 5, 2004

• #10

I would also check your grounds for corrosion. Both headlights have a ground wire. You need to pull the headlights and the headlight fender extensions to get at this connection.

 

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Richard Paige

Founding Member

Oct 29, 1999

107

0

16

Memphis, UT USA

Apr 6, 2004

#11

• Apr 6, 2004

• #11

Replace the headlight switch first. It's $10-15 at Autozone. That will fix the headlights going off. I had a dimming on my lights that was fixed by replacing the new autolite replica voltage regulator with one from the zone. Now the headlights are steady all the time with halogens.