vdhillon2

Hi,
This is my first post and I'm truly a newbie at this.
I just purchased a 1967 mustang restomod. It has a 347 Ford racing stroker engine with approx 400 miles on it. It appeared to do fine the first couple of days, but once I got the AC system charged and began using it, I can't keep this thing running.
At first it would start up first thing in the morning, but would die at work and not start. AC running or not running it wouldn't hold a charge. The voltage gauge always read 10v max running, with AC running it would drop to 8.
I replaced the battery, with an optima red top. At first it made the difference but within a day it wasn't working with the same problems.
My voltage meter was running 12.4v but will dip under 12v when running. I thought about alternator problems, but this is brand new with less then 500 miles on it, can it really be that?
It is a king chrome one wire 100amp alt. I took it apart, it all looked good so i put it back in.
Today i realized i should try and gauge the wire coming out of the alternator as that would tell me if its working, and sure enough its reading 11.67v with the engine running.
My question:
1.Is there a chance it is not the alternator, and possibly a wiring issue, as the wiring appears complex
2. If you had to replace the alternator would you replace it with the same one? It is a V belt configuration.

Thank you for any help in advance. I will be frequenting this forum and using it a lot as i will need the help. Hopefully one day to give back.

boogerschnot

Sounds like a voltage regulator problem. If you have a 1 wire alternator, it should be regulated internally. It sounds like its either not hooked up correctly or it is bad. Your charging system is just not working. Could you take a picture of your setup and explain how it is hooked up, all wires that you see connected between the battery, alternator and starter soleniod. Colors of the wires will help too.

boogerschnot

You need to know that when the car is running your voltage meter should read at least 14 volts. If not, thats your sign that you arent charging.

vdhillon2

Thanks for the reply. I do know that the charge should be 14v once started, thats why i'm wondering why this isn't working. My bigger questions is that the line coming out of the alternator should be putting out 17v or so correct? its not doing that as well, which i would assume means a faulty alternator.
The other thing that doesn't make sense to me is the line out from the alternator is not going to the starter solenoid where everything else seems to hub, it runs to a collection of wires on the front of the car which i don't know what they supply.
I tried putting up some pictures but they won't stick. Any idea how or can i send them to you?
I'll try pulling apart the wires today and follow where the line going from the alternator ends. As well get the wiring harness diagram out of the box and see what it says.
Thanks for the help.

Jonk67

Best way to post pics is to open a free photosharing acct. like photobucket, etc. and link from there.
You can take the alt. off and bring it into any auto parts store and they can test it on a free standing machine. That will tell you if the alt. is the problem or part of the problem.
Jon

jlg2002

The only way your alt will put out 17 Vdc is if it is "full on" and believe me it will last for about 3 -5 minutes before it destroys itself.
These cars are really simple to diagnose with a charging problem- you confirm that the alt input terminal has battery voltage on it and the the V reg plug A( green red) wire has battery voltage on it with the car running, From there you momentarily short the alt field to battery voltage usually at the reg ( F or white wire). plug and look for an increase of voltage across the battery with a DVM.

if voltage goes up the Vreg or wiring to the alt is bad if it don't go up,the alt is bad

Oops just red that you have the 1 wire system- all they need is battery voltage to the unit and speed. Verify batt voltage at the unit if it's there, If you can rev it up and the voltage doesn't go up, the alt is bad.

vdhillon2

I went back and cut off all the covers and zip ties.
The red positive cable comes into the engine compartment, it attaches to the starter solenoid. The alternator has a wire that connects to a y connector- one end goes to the a fuse cap, the other to the anterior lights labeled 'batter power connect'
The wire going back to the fuse comes back on the other side and back to the solenoid. Up to this point I didn't see where the alternator had any connection to the battery, so this is the first.
I wonder why they didn't just connect the alternator directly to the solenoid...any ideas?
With nothing running the single output from the alternator puts out 11.9v which is the same as the battery.
Based off all that I'm thinking the alternator is no good, and the wirings should be okay. Im gonna disconnect the alternator tomorrow and take it to pep boys to check Friday.

Jonk67

I don't have a single wire alt. but at some point the alt + lead should have a wire from the batt. + side of the fender solenoid in order to charge the batt.

Here is the stock wiring schematic to give you an idea of how the original wiring was with an external regulator if you don't have it:
http://hammar.dyndns.org/~djhamma/wi...7/67ignit1.jpg

I have avoided the chromed alt. as most are flash vs. quality. I hope the counter staff at your local Pepboys is better than the dozen I've been to, I use the local parts store with the most knowledgeable counter people vs. the ones that just know how to point at the oil rack....Let us know what the test shows.
Jon

rmodel65

vdhillon2

Thanks for the diagram, it does help a lot. From the looks of my wiring system, the alternator is not hooked up directly to the solenoid, but instead spliced into either wire 262 or 32.

I tried the battery disconnect trick, but it didn't work. Which i guess another reason why i'm not 100% sure it is the alternator. With the negative disconnected the car cont to run. I didn't test it for too long, so maybe i should give that another try today.
I have a single wire alternator which doesn't allow me to bypass the voltage regulator.

Thanks again for the help