What happened to my Plymouth Valiant's ammeter here?

[WH23G3G]

Ok this is the second post on this topic, it said there was an error on the first, so I hope it doesn't show up twice. My 65 Plymouth Valiant 170 ran decent and drove ok a few weeks ago. Everything worked, all lights, heater, and radio. It started up easier than my 73 Charger even with a worn out choke. It's got a brand new Year One engine compartment/forward light harness, and a donor dash harness from a Barracuda with the only wires being splice are the two main ammeter wires, using the posi-lock connectors. Well a few weeks ago when we were trying to tune the carb the engine stalled out so I went to restart it and the key did nothing. I couldn't understand why. It was a new battery and new cables too. So I noticed the dome light wasn't coming on anymore either and then I checked the headlights and they weren't coming on either. So I was stumped. I pulled the gauge cluster out to see if there were any burned wires and I saw nothing and saw nothing under the hood. I installed a new fusible link in the factory spot when I put in the new harness and it looked fine too. Well tonight when I was taking apart the gauge cluster to swap the ammeter which had never moved all the whole time the car was running fine. I noticed this on the back, it was all melted, and the cluster burned inside. When I got the car originally it had a coat hanger going to one of the ammeter studs, so I know there were problems before. It's possible I could've been using this bum ammeter the whole time so it never worked to begin with. But I have a spare cluster with a working ammeter in it that I was going to swap out. But I wanted to know what could've caused this meltdown? Could it have just been a bad ammeter? I'm assuming this is why there was no power at all after the carburetor stalled out the engine and I tried to restart it. I remember an article talking about the problems of 60s Mopar ammeters but can't remember where online it was. Is there an easy fix for it?

[Charger RT]

what amp alternator you have on the car. They used like 35 amp alternators stock back then. So if it has a 60 or even higher one it will smoke the amp meter. The bulk head connector has two wires going through it that also don't like higher amp alternators. They should be checked as well.

I bypass the amp meter on mine by tunning a wire from my alternator to the battery. This leaves both wires running inside the car to split the load used inside the car. There are threads on this site about a parallel circuit to help the two wires running inside and keep the amp meter but there is no upgrade for the amp meter.
Tim

[WH23G3G]

I don't remember which part number alternator is on my engine but it's been changed by whoever had it before me. Maybe that's when they had the ammeter go out too. I looked up the rebuilt ones from the parts store under a 65 Valiant 170 and it said they have 50 AMPS and one 46 AMP alternator. My 65 parts manual shows All Plymouth and Dodge models could use a 2098830 at 35 AMPS or a 2098850 rated at 40-46 AMPS. Mine has a heater, variable speed wipers, backup lights, and an AM radio, which I added from another 65 Valiant because I don't even think mine originally had a radio. Should I be going with the 35 AMP if I can find one or 46 AMP? I bet the one I have on there now is a 50 or 60 amp, it's just like the one on my 73 Charger. 

[Charger RT]

Like I posted I just upgrade the car to handle the higher amp alternator. 35 was not enough then. A lot of people are going even higher. I have a 90 amp denso I will put on my charger one day. There are many good threads on this subject do a search for some.
Tim

[WH23G3G]

Yeah I was going to read up some more on it. I just to prevent it or at least prolong it from happening again. I talked to the Remy tech support who remanufactures alternators, the one I have on the car. They said it doesn't matter what amperage the alternator puts out because the car will only use what it needs. They also said you could connect the two terminals of the ammeter together and do away with the ammeter totally. But I'm not sure what I'll do. I'm just wanting to know was there more than likely a wiring problem or just my ammeter was old and worn out? I want to swap in my extra one so I can finish the car but I don't want to reinstall it and have it meltdown again as soon as I put it in.

[68 RT]

Never use posi lock connectors. Especially on something like the main ammeter wire. I soldered mine and covered with heat shrink tubing. Posi lock connectors can cause huge amp draws and over heating. 

[WH23G3G]

I'm not to good at soldering, are the regular pressure crimp connectors ok? All the shops I know around here told me to replace my alternator and regulator after I told them what happened. I know a new dash harness is going to be in the future. Is there any other companies or persons making 65 Valiant/Barracuda dash harness besides M&H that supplies Year One? I don't know that the $550 is worth putting into this car being in the shape it's in. I've been lucky that I  haven't had to replace much of anything except the carburetor. Everything works, the engine runs, and transmission shifts good.

[Charger RT]

They said it doesn't matter what amperage the alternator puts out because the car will only use what it needs.

The statement above is correct but if the car needs everything the alternator can put out and the wiring and amp meter are designed for half of it things melt and burn. Would you plug a 12,000 btu air conditioner into a standard lamp extension cord? The cord might handle just the fan running but what happens if the compressor comes on? There are many here that have had the two wires in the bulkhead connector fry. You need to look at yours. These cars had issues with the amp meter and bulkhead connectors with stock alternators using a 60 amp unit will increase this issue. My 66 dart had the amp meter crap out years ago. (I think A body amp meters are crappy compared to B body ones) When my amp meter in my charger was still showing amps before I added a wire I was very careful when I started it up after sitting for a while because the alternator will put out more then the amp meter or bulkhead connector connections can handle until it recharges the battery and its output drops.

After I repaired the minor issue my bulkhead connector had I ran an 8 gauge wire from my alternator to my battery. This means the amps needed to recharge the battery does not need to go inside the car to the amp meter they go right back to the battery. That wiring change basicly makes the amp meter just stay centered. Now the two wires running through the firewall to the amp meter now splits the load the inside of the car needs. The original setup the amp meter wire from the alternator carries all the amps into the car that the car uses plus what ends up going out the other wire to charge the battery. Nacho has written quite a few threads on adding two wires to carry the load in and out plus the amp meter will still work. But if the car needs most of what the alternator can put out it does pass more amps through the amp meter then it was designed for. Under normal operation this should be ok. Search for his threads they are a good read.
Tim

[WH23G3G]

Ok I'm still reading up on everything I can find on the issue. I believe I'll replace the alternator just in case. I tested it for function while I had some parts off of the car. The alternator worked correctly but what was the same one on the car when I got it about 4 or 5 years ago. It's either the 50 or 60 AMP version. I see Napa carries a 35, 45, and 60 amp reman alternator. So I guess I will go with the 35 amp because that was what was standard on this car. I'm probably going to do that and reinstall my other good gauge and get the rest of the mechanical work I've got to do to get it driveable. 

[WH23G3G]

Ok I pulled the alternator off my 65 Valiant today and it's a P7001. Which I think was from Advance as they show a P7001 as replacement for a 65 Valiant with a 170, but it's a 60 AMP alternator. I found a 35 AMP alternator Napa can order which was standard equipment on my 65. I read this article on Allpar;  http://www.allpar.com/fix/alternator.html
It says it is a must to add additional wiring to run the 60 AMP alternator on older Mopars that were originally designed for 35 AMP alternators. So after reading it I hope I assume correctly that if I replace the alternator with a new 35 AMP alternator and replace my ammeter I should be ok wiring it up the factory way.

[Charger RT]

What was written in the link is basicly what nacho has been doing here. He goes into more detail and has tech support on this site. Putting on a 35 amp alternator will lower future issues but is basicly small it was small then. You still need to check the two bulkhead connector wires to see if they are damaged.
Tim

[WH23G3G]

I checked the ammeter wires which I originally thought I used posi-lock connectors on. However, these were the two that I actually soldered and shrink wrapped when I had the harness out. The ones I posi-locked were for the radio. I looked at the connectors and didn't see any melting. I cleaned everything and any corrosion when I had the harness and bulkhead connector out. Because I remember reading about the problems in an old Mopar Muscle issue.