'86 5.0 mgm alternator

[sly]

my RR thread is a cluster since it's all the panthers I have owned. Searching for anything in that thread is a pain. Plus most of the images are no longer available.

[Toploader]

we don' really get a ton of traffic on here, and the policy towards moderation has always been fairly hands-off unless its really needed. I've been on plenty of other forums where if you say the wrong thing or post in the wrong spot you get yelled at or suspended or have your posts removed. Not a fan.

LOL, sounds like the Studebaker forum:-((

[Toploader]

Gents the latest sad story:-( Ok as you all know one week ago I put in a new battery. Today came out to start and move the car.............dead dead dead. NADA:-( So, guess it was not the battery. It is obvious that this is an intermittent problem. My bud wants me to leave him the car so he can check it every day to discover where the drain is emanating from. ...............that is a real PITA as I have to drive out to LI, then take LI RR and subway home:-(. Question.............many here have said change the alternator as the diodes are known to cause drain problems, I wanted to just change the alt, but he does not like being an R&R person, rather wants to actually determine where the problems are. So, for the time being I pulled the two plugs going into the alternator, if it is the alternator then would pulling said plugs prevent the ongoing drain?............assuming it is not anything else? After about a week if I return to start the car and it is dead, well its not the alt, if the car starts (with the alt plugs removed) then this would prove that yes, the alt is indeed the culprit. So gents, thoughts about taking the plugs out???

[sly]

Typically it's the charge wire that will be pulling current when off if the alternator has died that way. If the voltage regulator is at fault, you'll get no charging action (or overcharging) and know right away. as you'll get idiot lights on for that one.

[friskyfrankie]

Gents the latest sad story:-( Ok as you all know one week ago I put in a new battery. Today came out to start and move the car.............dead dead dead. NADA:-( So, guess it was not the battery. It is obvious that this is an intermittent problem. My bud wants me to leave him the car so he can check it every day to discover where the drain is emanating from. ...............that is a real PITA as I have to drive out to LI, then take LI RR and subway home:-(. Question.............many here have said change the alternator as the diodes are known to cause drain problems, I wanted to just change the alt, but he does not like being an R&R person, rather wants to actually determine where the problems are. So, for the time being I pulled the two plugs going into the alternator, if it is the alternator then would pulling said plugs prevent the ongoing drain?............assuming it is not anything else? After about a week if I return to start the car and it is dead, well its not the alt, if the car starts (with the alt plugs removed) then this would prove that yes, the alt is indeed the culprit. So gents, thoughts about taking the plugs out???

Which is why I advised to check out the drain (especially the alternator and it's wiring) BEFORE putting in a new battery. Should be able to revive the new battery but charge it with a machine and not let the (new) alternator. I do understand your friend doesn't want to be a parts replacer (and I agree with him) but I also understand the travel problems that causes for you so I'd completely check out the wiring to and from the alternator and simply replace it. Save the "Dick Tracy" routine for some other time!

[Toploader]

Typically it's the charge wire that will be pulling current when off if the alternator has died that way. If the voltage regulator is at fault, you'll get no charging action (or overcharging) and know right away. as you'll get idiot lights on for that one.

Sly, I do not get "idiot' light illumination. Guess the VR is good. Oh, BTW, which one of the wires is the "charging" wire, the small or the large plug?

[Toploader]

Which is why I advised to check out the drain (especially the alternator and it's wiring) BEFORE putting in a new battery. Should be able to revive the new battery but charge it with a machine and not let the (new) alternator. I do understand your friend doesn't want to be a parts replacer (and I agree with him) but I also understand the travel problems that causes for you so I'd completely check out the wiring to and from the alternator and simply replace it. Save the "Dick Tracy" routine for some other time!

Frank, the thing is after we put the new battery in, they hooked up the meters and found no drain!........which is why the shit is intermittent:-( So, lets see what develops with the alt taken out of the circuit, guess I should know within one week as I do not plan of leaving NYC next week.
Many continued thanks for all the help!!!

[sly]

the large plug that has the two same colored FAT wires is the one I'm talking about. The two fat wires are the charge wires. If you have an ammeter (multimeter with "Amps" setting) you can put it between the alternator pin and one of those wires in the connector after disconnecting it and if it reads more than zero, your alternator is bad.

[friskyfrankie]

Frank, the thing is after we put the new battery in, they hooked up the meters and found no drain!........which is why the shit is intermittent:-( So, lets see what develops with the alt taken out of the circuit, guess I should know within one week as I do not plan of leaving NYC next week.
Many continued thanks for all the help!!!

Do let us know as this is VERY interesting! As for "tests" showing the problem, I have seen all kinds of tests showing a good alternator and it was the problem. So "are you going to believe me or your own lying eyes"? LOL Hope you find it soon as this shit can be REALLY frustrating.

[Toploader]

Well it seems living here in NYC I have taken in stride the rat and crime situation, but the car?.........THIS SHIT PISSES ME OFF!!!!!!!!!!! :

[Toploader]

the large plug that has the two same colored FAT wires is the one I'm talking about. The two fat wires are the charge wires. If you have an ammeter (multimeter with "Amps" setting) you can put it between the alternator pin and one of those wires in the connector after disconnecting it and if it reads more than zero, your alternator is bad.

Sly, can the alt be good on one day, yet bad on another day? In other words can the alt be intermittently bad? Many have said diodes bad, if true can they be as I said good on one day and bad on the next? Tomorrow I will try to get down to the car and test as you have suggested. May I "assume" that one of the multi-meter probes can be placed on any of the alt pins and the other probe on any one of the wires inside the connector?

[friskyfrankie]

Forgot to advise to also check/replace the large connector on the top of the alternator. Not sure what they use to make it but it looks like a waxy substance and it does go bad. It's a good place to start before even replacing the alternator - I'd have both on hand, just in case. The connector on the voltage regulator has a lower failure rate so probably not an issue.

[Toploader]

Forgot to advise to also check/replace the large connector on the top of the alternator. Not sure what they use to make it but it looks like a waxy substance and it does go bad. It's a good place to start before even replacing the alternator - I'd have both on hand, just in case. The connector on the voltage regulator has a lower failure rate so probably not an issue.

Frank when I pulled off the large connector from the alt, the inside looked like it had a white-ish lube inside, maybe di-electric grease?..........the alt was replaced about 25 years ago.

[friskyfrankie]

If you do change out the alternator, I'd do the connector as well.

[Toploader]

If you do change out the alternator, I'd do the connector as well.

Where to purchase said connector?