I have a 67 El Camino, That I purchased in gooding condition. But any time you use any electrical such as head lights power windows the volt drop from about 14 volts to 12 volts. I was not sure if this is a normal voltage drop.

I have a 67 El Camino, That I purchased in gooding condition. But any time you use any electrical such as head lights power windows the volt drop from about 14 volts to 12 volts. I was not sure if this is a normal voltage drop.
No, not normal. Does it happen at driving speeds or only at idle? What kind of alternator. If it only happens at idle, the alternator is to small or is underdriven. If it happens at any speed, i would look at ungrading the alternator. If it is externally regulated, upgrade to a internally regulated alternator.

It will happen at any speed. I have upgrade to a single wire 100 amp altenator. the voltage does stay constint. such when i turn the lights on it drops from 14 to 12 and then i turn the lights off and it charges back to 14. could there be a voltage regulator at the fuse box that could be bad?

Mine did the same thing. The problem is that the wiring runs from the battery thru the fuse box up to the switch and back down to the headlights and all that monkey motion creates voltage loss. The solution is to use relays close to the headlights and pull the power off a power buss. I used the horn relay for the power supply and the headlights are much brighter. There is a good web site that I can find for you if you need it that explains the wiring. dan w

You might try cleaning the terminals on the headlight connectors and the light switch. They could be corroded which would add resistance to the circuit that is causing your voltage drop.

Mine did the same thing. The problem is that the wiring runs from the battery thru the fuse box up to the switch and back down to the headlights and all that monkey motion creates voltage loss. The solution is to use relays close to the headlights and pull the power off a power buss. I used the horn relay for the power supply and the headlights are much brighter. There is a good web site that I can find for you if you need it that explains the wiring. dan w
the name of that web site would be great thanks for all the help

this is the website http://www.madelectrical.com/index.shtml
I can send you a couple of pictures of mine if it will help
You need 2 relays one for high and one for low beams.


dan w

I forgot when you get to the website click on "electrical tech" and look at the first subject. dan w

It will happen at any speed. I have upgrade to a single wire 100 amp altenator. the voltage does stay constint. such when i turn the lights on it drops from 14 to 12 and then i turn the lights off and it charges back to 14. could there be a voltage regulator at the fuse box that could be bad?
A one wire alternator is really not a upgrade, a 3 wire internal is better.
http://www.madelectrical.com/electricaltech/onewire-threewire.shtml
Are you using any kind of power pulleys? If so even the biggest alternator will have poor output if it isn't spinning fast enough, see here
http://www.powermastermotorsports.com/power_pulleys.html

airic67,

The Mad relay conversion is a nice one.

But, these cars did not experience that much voltage drop when new. I'd suggest finding the cause of it, which would typically be either corrosion on terminals or a weak point in a wire. The Mad kit will brighten your headlights but it won't fix your excessive voltage drop.

If it where mine, I'd be wondering what else is experiencing the drop. Dan W is right about the long wire run to the lights. Other electrical devices have shorter runs. And if your drop is only in the head light circuit, no big deal. But what if your ignition or radio are experience the a similar drop? You'll be giving up performance or damaging parts.

the volatge drop occurs when i use any electrical such as windows and the electric fan that is why i thought maybe wiring problems at the fuse block

Like Undee said we need to know alt type and how you have it hooked up this is usually the big problem.

Mine has a cs130 and the lights are as bright as any relay system but they are nice intalls but I chose the cheaper route.

Go back to the mad electric site and look up the wiring diagram that they have for electric fans and how to wire them and the relay. If you follow their diagram that should solve your problem. I have a 67 with dual fans and no problems.
http://www.madelectrical.com/index.shtml