Hey guys, looking for some input.
Upgraded the factory alternator on my 71 to a Powermaster, 150 Amp 12si unit.
Ran a new 6 ga. charge wire to the solenoid per the manufacture's instructions.
Car will not crank, completely dead, no lights, radio, nothing.
Have triple checked my connections.
The battery is good.
Will not jump start.
It should be so simple-what the … am I missing?

Alan

 

Car should crank and run without an alternator.

What voltage are you reading at the battery?

Did you wire something backwards at some point, and toast a fusible link somewhere?

Please post pics! That might make it easier to than guessing.

 

I've got 12.4 volts at the battery. Also checked power with a test light-hot at new starter wire connection at alternator and solenoid. As far as wiring something backwards, I guess anything is possible, but it was a simple disconnect and reconnect of 10 ga to 6 ga starter wire.
I think I'll take out the new alternator and reinstall the old one and see what happens.
Will also post pictures.

 

So- Did you bypass the 10GA wire completely?

Running the 6GA straight to the starter solenoid removes any protection- you have the entire capacity of the battery ( 700+ amps) running all the way to the alternator through the engine compartment.
6GA is rated at 80A- so that charge wire unprotected becomes a fire hazard (see chart). If the alternator is shorted out- smoke comes out of the alternator and it stops putting out power.
However- if the battery is shorted out-it's like the energizer bunny- it keeps going and going...

The fuse panel-ignition- lights without the 10GA connected from the Alternator to horn relay- now it's only source of power from the stater solenoid protected by a fusible link.

My guess is you have burned the fusible at the starter solenoid,

See if you have any power at the fuse panel.

I HIGHLY recommend when upgrading the charge system/wires/alternator on harness that was designed 50 years ago with no thoughts on running 100A through it- This

A fuse at the battery- 225A seems to be the best from real world use Blue Sea is the company

 

What exactly did you mean when you said "if the battery is shorted out-it's like the energizer bunny- it keeps going and going..." ?

Is the battery is shorted out externally or internally? I spent decades testing batteries and I have seen them both short internally and externally. I have seen a battery that had an internal short that exploded after sitting a few minutes. When a battery shorts out internally you normally drop a cell or two when it happens along with great amounts of heat. It depends on the type of short. The sediment on the floor of the cell is frequently lead and it can get high enough to touch the bottom of the plates causing a short. Other times the plates will either fracture or break off the cell interconnect bars and fall against the other plates, it doesn't take long to wear through the separators in between the cells The result will be a very hot battery and if it continues to get hot they can melt or explode. I heard a buddy's Dodge Van have a battery explode and it was under the hood but 200' away it still was very loud. It was a mess the clean up as the electrolyte was all over the engine compartment. It was caused by a bad Alternator that simply overcharged the battery until it built up hydrogen gas and then there was something that lit it off.

This past weekend my Son was driving a car that had a battery Internally fail after 7 years of usage.. It was working fine and then just stopped providing 12 volts. He jump started the battery and the car would work until he shut it down. I suspected he had a internally shorting battery. Yesterday he was trying to start the car and he noticed smoke that smelled like Sulfur coming out of the battery's vent. When he was starting the car with a jumper box it could start using the power from the alternator to keep it running. His newer car would not go anywhere because the voltage was not there to release the rear caliper parking brakes. The battery's case was deformed by the heat it generated and fortunately the vent opened or it would have likely exploded. I am so grateful that it did not pop or catch on fire.

You are right about fusing the battery, I have done that as well but using a Marine grade Waterproof/Water resistant Circuit breaker for 12 Vdc. It is easy to turn on and off and I have it in the center rear compartment. I have a 200 amp fuse on my battery which makes shutting off the entire car very simple. I have found that Marine grade wire is easier to work with being made of smaller strands all wound together. It bends and can make turns that are hard with standard #4 cable. It is important to get the fuse mounted as close to the battery as possible for maximum protection.

There are the two Fusible Links down by the Starter that need to be checked and two more up near the alternator and Horn Buss. They do burn out even without melting the outer case or rubber. Take two sharp needles and push them into the wires before and after the fusible links to verify that it has continuity.

 

I'm talking about the 6GA wire from the starter to the alternator.
An external short to the unprotected wire - connected to a source that can supply way more current than the wire can handle- easily melting it-
The battery won't stop- it'll be going and going till something bad happens!!!

Reference-

 

As I mentioned before I tested batteries for a company that made large Remote Hybrid Solar System using Photovoltaic panels, Wind Turbines, Micro Hydro and Diesel Generators along with a huge bank of batteries feeding Inverters for small villages that had not been electrified. I played with all types and brands of batteries and learned who is honest and who isn't about their battery capacities. I had two computers stations for discharging the battery at a constant current and recharging them. This data showed the Bell Curve of a battery discharge and re-charge characteristics. In our line of work this was vital to designing a long lasting system.

Batteries are dangerous in the hands of an untrained tech or a reckless homeowner. That one in your picture is proof positive. I have seen many burned or exploded cases from defective batteries. What really scares me now is the new battery powered Cars are using hundreds of volts and above 58 Vdc the DC current can and will kill you if you are not really careful.
I have a 120 amp alternator and I ran a #4 gauge marine wire and I have seen no heat generated in the cables. I mention the Marine grade wire as it is more expensive but it is very flexible and easy to use since it is tiny strands wrapped together instead of the virtually solid wires automobile's use.

Once out in the deserts of the U.A.E. I was load testing a system and my helper attached both the positive and negative leads of a 5000 ah 120 Vdc battery bank directly to one side of a resistive Load bank. This load bank was air cooled and had to big solid copper bars, one for Positive and one for the Negative and in between there were resistors for various values. Both lines were mistakenly attached to the two ends of a single copper buss bar. When the power system was turned on there was a rattling sound and poof nothing. It turned out that I had melted the contacts off the Mercury Displacement switch by boiling the mercury inside the device's case. We had a mercury contactor explode at our office and they shut down our facility while the guys in space suits cleaned up the Mercury. It took a week to clean up the mess.

Upon returning to the U.S. I spoke to the manufacturer who was amazed that the relay did not explode like they normally do when you short one out. Had that relay exploded it would have been about 18-24" from my face and the boiling mercury would have done some damage to my upper body. I would have never survived to make it to a hospital as I was 100+ miles away from any roads out in the soft sand desert and it took hours to get there. I am a very lucky man according to the manufacturer. Me, I learned never to trust anyone when working with big battery banks, always double and triple check before power is applied.

Practice SAFETY and live longer!