Dont wanna burn up my car

[Rosco]

I've been seeing off and on about an inherent problem with how the charging system runs too much current through the ammeter under certain conditions leading to a potential fire.
I followed a link to "Nacho's' "Some considerations about the charging and wiring upgrade..."
Wow. Lllllloooooooonnnnngggggg!! OMG. Too, so many typos, hard to follow.
Could someone dumb in down for me? Question is, can I keep the ammeter functioning (I like it and have a long history of staring at it while I'm cruising at night and tapping the gas to get the needle above the charge line) and still be able to save the car from potentially burning up? I have a '68 Fury ll w/ a 318, no A/C.
Is the idea to replace or bypass the original wiring to the ammeter with bigger gauge wires?
My major issue is driving at night with the headlights and heater going at low speed and the ammeter shows the car is discharging. I feel it the next morning when I go to start the car and it barely has enough juice to start. Too, headlights are too dim at low speeds. I often drive a dirt road with surprise cows all over the place so got to go slowish.
I know there's been a LOT of posts about this problem and I apologize for my blatant laziness. I'm doing a sort of restoration and don't want to get through it all only to have the car catch on fire. And I'll admit I don't fully understand the diagrams and some of the terminology.

 

[LocuMob]

Underhood Ammeter Bypass

@c-barge simplified it in this thread. The first few posts are all you really need. But your Amp gauge will not function correctly, so it's recommended to install an aftermarket volt gauge.

My car wouldn't start, the ammeter is hanging on for dear life, so I did this and BAM! the car fired up.

Read through the thread and get your car set up.

 

[67Monaco]

You could also install headlight relays and take the load directly from the battery for the headlights. It takes the load off the ammeter, which will then read incorrectly, but it will function. As a bonus, the head lights will be brighter. I did both bypassed the ammeter and installed relays for the headlights.

 

[saylor]

x2 #Metoo do both mods


try not to die -

- saylor

 

[Rosco]

OK. I'll read the new thread. But I still want to have my ammeter. I wonder how many people have had fires from this issue?

 

[Big_John]

You have a problem with the charging system not putting out enough current.

Don't do any mods until you straighten that out. Can't get any simpler than that.

Your car isn't going to burn up and the ammeter didn't kidnap the Lindberg baby so quit wasting your time with that right now. They are great mods, but only do them AFTER you've figured out what the issue is with low charging output.

 

[Rosco]

You have a problem with the charging system not putting out enough current.

Don't do any mods until you straighten that out. Can't get any simpler than that.

Your car isn't going to burn up and the ammeter didn't kidnap the Lindberg baby so quit wasting your time with that right now. They are great mods, but only do them AFTER you've figured out what the issue is with low charging output.

I've always run stock eg Kragen's/O'reilly alternators and have always had this problem.
Summit Racing recommended a high-output alternator but I'm concerned that it wouldn't put out enough charge at idle/low RPM speeds to address my issue and they could only offer me overall max. output specs.
I read the post by CBarge and am still a bit confused on what exactly the problem is with the stock ammeter- components inside the meter fail over time? Wire gauge too small going to the meter? But I agree, don't need to "fix" the meter until I get better charge at low speeds. My ammeter's been working fine for 51 years...
I always assumed any Fury of my vintage would have had this issue... Wow, if everything's running right you mean you can roll along under 20mph with bright headlights and the heater blasting and the battery charging? That would be great!!!

 

[saylor]

enough mopars and chevys and other makes died from dash ammeter fires for there to be page after page after page of information on how to get around it.

and there are pics in this forum of fried cars.

and in mopars case the factory themselves eventually changed the wiring - the 'fleet bypass' IIRC - passing thru a firewall grommet on taxi/hd/police/etc.

i agree with mr big john, a person who will never give you bad advice, but i say the ammeter IS part of the charging system, and therefore should also be considered.

you need to study mopar charging circuits. in these old of cars its pretty basic. but to mr big johns larger point - your system should be able to generally run everything it was originally equipped with - and you should do stuff like check/clean all your grounds, inspect wiring, etc., etc.

but if its like a 35amp ALT, and you have the heater and lights on at night, at idle at a stoplight at 650rpm, you will have yellow lights - its givin all its got scotty.

you can still have your ammeter, some people join both wires to 1 post. mine is in dash but unhooked. Understand you have a HOT wire on a metal post inside your dash - just sitting there. If you do choose to leave the ammeter in-circuit, at least take some shrink wrap and totally cover up the posts.

try not to die -

- saylor

 

[saylor]

I read the post by CBarge and am still a bit confused on what exactly the problem is with the stock ammeter- components inside the meter fail over time? Wire gauge too small going to the meter?

maybe, YES, and 51 years of heat cycles and seasons and the connections can get loose and etc.

the way the original mopar design is there are weak spots where the entire power of the car has to pass thru some places it shouldnt have to. like this circuit here. or the headlight circuit passes thru the floorboard dimmer. there is a better way.

 

[saylor]

and while a larger ALT may (is) in your future, you cant just bolt it in or you will melt everything else.

welcome to mopar charging circuits 101. enjoy your stay.

 

[Mr C]

As Big John mentioned, test your current system before wading into other mods. You need a baseline to go from.

Are you still using the mechanical voltage regulator? It may be on its last legs. Stock appearing solid state ones are available cheap.

Start the car and put a meter on it to see if you're charging as per FSM specs first.

 

[Big_John]

i agree with mr big john, a person who will never give you bad advice, but i say the ammeter IS part of the charging system, and therefore should also be considered.

Thanks, and I agree that there is some restrictions that might cause some issues for best performance, I think you agree that it really comes down getting it all right first before making mods.... and I also will make the argument that it isn't the ammeter itself as a stand alone culprit as so many seem to think. The ammeter in these cars is a pretty robust piece. IMHO, the issue lies with the connections to the alternator. The bolt on connections on the back being one along with all the others in the chain.

On cars like my '70, there's a connection under the steering column where it is known to fail and bypassing it with a "solid" connection eliminates a lot of issues, but that connection, while far removed from the ammeter in location has still been seen as the dreaded ammeter, because it's in the circuit. See what I mean?

 

[saylor]

yup -

OP get a multimeter and some sandpaper and check everything - grounds, wires, connections, terminals, straps, etc. clean BATT terminals. check ALT/regulator output as above ^^. check BATT output. check ground continuity. if you have .02 V or more loss at any point to point there is room for improvement. etc.

but also understand this is 50 yr old wiring, that is min AWG spec, and its tired. its crusty. the grounds are wore out. the sockets are half melted. the dimmer switch has had 50 years of salty boot on it.

tbh if you are trying to spot cows and snipe hunt and whatever out on a dirt road, you may want to do the crackdeback slant6 dan headlight bypass sooner than later.

it will give you full BATT power to drive your headlights via relays, instead of thru the marginal, 50 year old stock wiring harness.

 

[Big_John]

I've always run stock eg Kragen's/O'reilly alternators and have always had this problem.
Summit Racing recommended a high-output alternator but I'm concerned that it wouldn't put out enough charge at idle/low RPM speeds to address my issue and they could only offer me overall max. output specs.
I read the post by CBarge and am still a bit confused on what exactly the problem is with the stock ammeter- components inside the meter fail over time? Wire gauge too small going to the meter? But I agree, don't need to "fix" the meter until I get better charge at low speeds. My ammeter's been working fine for 51 years...
I always assumed any Fury of my vintage would have had this issue... Wow, if everything's running right you mean you can roll along under 20mph with bright headlights and the heater blasting and the battery charging? That would be great!!!

OK, again, you have an output issue.

It can be one of a lot of issues, or a combination of issues.

The first thing you have to understand is that there has to be some diagnosis of what the problem is. The "bypass" can be done literally in minutes if you really want to do it, and I'll never tell you it's a bad mod, just that it's NOT a "fix all" for a charging problem.

You need to get out the voltmeter and get to work... Assuming won't help... Firing up the parts cannon and shooting it at the car will only cost you money and maybe fix the problem if you get lucky.

Summit racing is always going to recommend their high output whatever. If I was in the business, I would recommend whatever high output widget I was selling too. It's all about the $$.

If you want, we can go down through how to diagnose the issues.... But you gotta want to do it. I've beat my head against the wall too many times lately to go through it without some commitment.

 

[dart4forte]

I've been seeing off and on about an inherent problem with how the charging system runs too much current through the ammeter under certain conditions leading to a potential fire.
I followed a link to "Nacho's' "Some considerations about the charging and wiring upgrade..."
Wow. Lllllloooooooonnnnngggggg!! OMG. Too, so many typos, hard to follow.
Could someone dumb in down for me? Question is, can I keep the ammeter functioning (I like it and have a long history of staring at it while I'm cruising at night and tapping the gas to get the needle above the charge line) and still be able to save the car from potentially burning up? I have a '68 Fury ll w/ a 318, no A/C.
Is the idea to replace or bypass the original wiring to the ammeter with bigger gauge wires?
My major issue is driving at night with the headlights and heater going at low speed and the ammeter shows the car is discharging. I feel it the next morning when I go to start the car and it barely has enough juice to start. Too, headlights are too dim at low speeds. I often drive a dirt road with surprise cows all over the place so got to go slowish.
I know there's been a LOT of posts about this problem and I apologize for my blatant laziness. I'm doing a sort of restoration and don't want to get through it all only to have the car catch on fire. And I'll admit I don't fully understand the diagrams and some of the terminology.

A good read. Exactly what I did. Also, FABO member Crackedback makes a nice HL relay setup. Give Rob a shout.

 

[mrfury68]

As Big John mentioned, test your current system before wading into other mods. You need a baseline to go from.

Are you still using the mechanical voltage regulator? It may be on its last legs. Stock appearing solid state ones are available cheap.

Start the car and put a meter on it to see if you're charging as per FSM specs first.

I can't stress this fact enough, you need a baseline before doing any mods. If your baseline test checks out, get a solid state voltage regulator if you don't already have one. The old breaker point style will fail eventually.

 

[Imperialist67]

Underhood Ammeter Bypass

@c-barge simplified it in this thread. The first few posts are all you really need. But your Amp gauge will not function correctly, so it's recommended to install an aftermarket volt gauge.

My car wouldn't start, the ammeter is hanging on for dear life, so I did this and BAM! the car fired up.

Read through the thread and get your car set up.

THANKS for posting this - great info.!

 

[Big_John]

@Rosco
I hope I didn't scare you off.

I've gone through some long winded explanations in some other threads and gotten kind of frustrated, so I may have come on a little strong. Sorry if it looks that way. I do want to help.

A little reading: Alternators and Regulators (Session 228) from the Master Technician's Service Conference

Accompanying video:



I'll show you how to set up a load test, similar to the service procedure, without a carbon pile, using just a voltmeter and a jumper.

 

[LocuMob]

THANKS for posting this - great info.!

I'm just riding coattails.

But it did get my car to start and move it to storage. Still need to address the issue which is known.

 

[Rosco]

Thanks for all the input. I've got the J O B keeping me busy but love hearing all the thoughts on the ammeter issue and the Mopar charging system.
I'm about 2 1/2 months out from being able to test for charging issues as I've got my car's engine bay mostly disassembled and am in the process of putting it all back together. I'll look forward to testing everything and deciding what we need to do once the motor's running.
I've been reading about the ammeter issue and it piqued my interest. When I put all the parts back onto my car my main goal here would be avoid a fire. Second, I'd like to keep using the stock ammeter (looks like they have NOS ones for my Fury all day long, btw) but I agree I need to get some data on how the (charging) system is working and then decide what to do. The main thing, as I mentioned, is that my lights are dim when driving at low rpm (with the heater blower blasting) and the next morning there is a noticeable voltage drop in the battery's starting ability. So, bright lights at low rpm, not draining the battery at low rpm and not setting the car on fire.