First of all! I'm not real experinced... However I love my car.. So I was having some problems with the charging system in my 72 mach1. I replaced the alternator, voltage regulator, and battery. I can tell at somtime or another there was a fire near the cylinoid and voltage regulator but the car ran fine just wouldn't charge the battery and if running and the battery was diconected they vehical would shut off? It seems vehicals of that age should run of the alternator alone. I wa attempting to fix this and was having trouble finding a voltage regulator harness. I live in AK.. However i found a complete wiring diagram for this car. I rewired the altenator and voltage regulator as the diagram showed. Most orginal wires you could see the color sceme. So when finished I started the car!! Runs fine i check lights, blinkers every things seems to work fine I go disconnect the battery sure enough the car stays running. I really feel good about myself! I get back in the car and play with the radio and lights some more and THEN I turn on the heater fan blower and the car Dies!! Hmm I shut of the fan and reconnect the battery and restart the car and try the fan agian. Once agian the car dies only this time there is no restart!! It turns over however no power going to the coil no engine fir at all!! What Happen?!?!?! I'm stumped I see on the diagram the blower motor does get power from and link at the ignition with the igniton wires!! Can any one help me? I have considered a complete new wiring harness??

 

Thanks for ALL the help guys.. I'll try another forum..

 

Give people time. This is not an easy question that just anyone can answer. It will take the right person with a lot of knowledge in this area.

 

Why did you disconnect the battery in the first place? I would never tell anyone to disconnect their battery and have the car depend on the alternator alone. This is a recipe for disaster for your entire charging system. The alternator is depending on the battery to handle the sudden spikes in power, if you take that away it will cause quite a bit of stress on the alternator and voltage regulator as well as any fuses in between. I would guess this is the case for you when you disconnected your battery and started turning on accessories. It sounds like you have a short or blown fuse somewhere. Start checking those fuses, if you don't have a test light- get one.

So you rewired some of the car. Make sure your grounds are clean and tight or you will have problems. Also be sure the new wiring you used is atleast as large as the wiring it has replaced.

As has been stated, this is not an easy problem to fix- it's going to take some trial and error and a little bit of patience, otherwise take it to a shop and have the problem solved.

 

it's ok to run with battery disconnected for a few seconds to see if the alternator is charging. so your fix worked. but then should have plugged the battery back in.

the first thing I would check if you have 12V+ at coil+ when ignition switch is in 'on' position.

 

Sorry guys I have tried a few diffrent forums and no one seemed to wanna help. I was beginning to think the same had happen here however I am sorry and appreciate the help. As for the problem as said I'm not real knowledgeable and i knew if i unhooked the battery i would know if the car could depend on the alternator. Didn't relize i would cause myself more work. I checked the positive wire going to the coil and have no power. As far as i could tell all of the fuses are good? I will be investing in a test light. Thanks agian guys.

 

I would invest in either a test light or multi-meter. I am not familiar with the 72, but one thing I have found on my 66 is the harness plug connections through the firewall have gone south or sometimes just a wire from point to point fails.
A multi meter or test light will confirm continuity from the coil to the switch. It saves a lot of tail chasing.

 

Where is a good place to buy wiring harnesses for my 72 Mach1 I am considering replacing most of the wiring anyways! The wiring under the dash is a mess aswell. The problem is I live in Alaska so things are hard to get!
Thanks