Higher rated ammeter

[mjb765]

I am looking to upgrade the alternator on my 69 Bee and wanted to retain the factory ammeter. I called Gary (the tachman...www.tachman.com) who claims to make the factory ammeter handle up to 110A which would be perfect. I have 2 problems...first--he is backed up 3 months with work...and 2nd--he needs the entire cluster so HE can install the ammeter and test it. I really don't want to send my entire cluster since the rest of it is fine and works, but he won't just modify the ammeter. Does anybody else do this or know of a voltmeter than can fit easily in the dash without getting into very intricate mods? I was hoping not to have to try to dismantle a voltmeter and paint needles etc to get this to work. I don't know if I have that kind of patience.

 

[Nacho-RT74]

the factory ammeters are able to drive more amperage than gauge reading JUST IF everything is tight and clean, but needle won't be far from the actual reading. 40 to 60 amps.

Not recomended though, at least for long time, not even the full reading. More parts will blow way before the amm if try to keep the full load on stock system

 

[mjb765]

I'm running new wires for the batt and charge bypassing the bulkhead connector....the ammeter is going to be the weak link.

 

[Nacho-RT74]

the ammeter won't sense never 110 amps, because with an alt like that the batt will never get discharged, so the ammeter will never sense the load coming and going from and to the batt.

the ammeter is actually a BATTERY STATUS gauge, not really an alternator gauge as factory made us think. If you keep as stock designed wiring, with all the accesories correctly feeded from alt side and never from batt, you'll never see the ammeter moving ;)

BTDT

more here:
http://www.dodgecharger.com/forum/index.php/topic,33574.0.html

 

[mjb765]

While I appreciate the info, I would still like to run an ammeter that is made to handle an alternator with more output--whether or not it actually sees all of it. Do you know of anybody else that does this upgrade other than the tachman?

 

[Nacho-RT74]

Police and Cab cars got 80 ammeters units at least on earliers 70s. That's the bigger factory optioned.

However all these AS FAR I KNOW where on standard cluster haven't known about rally cluster with these.

( trust me, you won't need it ;) I'm running a 100 amps alt with my stock ammeter )

The only momment you can get worried about the ammeter handling the load is if accidentally the batt get discharged enough ( fully discharged or allmost ) to get lot of juice from alt. If that's the case is not good to recharge the batt on car anyway

 

[mjb765]

Since I am planning on adding A/C and upgrading headlights and possibly a bigger amp for the radio I was thinking of a 1 wire powermaster alternator. Rather than go to the 75Amp, I was thinking of going bigger--just in case I need it. Can I go to a 140A unit and do the following: bypass the factory ammeter and install a voltmeter,run an 8 ga wire to the starter realy from the alt using a 12ga fusible link, and bypass the bulkhead connector completely and feed the interior with a wire coming off the starter realy where the alt connects? That should handle any charge load and still supply the rest of the car with power.

 

[440roadrunner]

mjb, the entire problem with Mopar ammeters is and always has been the wiring TO them, and the bulkhead connector. Read this excellent MAD article on the whys and what happens:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

The really big weak point is the bulkhead connector, the terminals of which were NEVER designed for the kind of amperage they must carry. Mopar knew about this early on, if you can find documentation here and there, the "fleet", police taxi, and higher amp alternators had modified wiring which even though using the ammeter, supplied larger wire through separate grommets in the firewall. If you have shop manuals, look through them, that is in some of them. Just shunting the ammeter is not much help when you still have the same old, probably damaged, corroded, bulkhead connector.



I LOVE ammeters, but I finally threw in the towel on my Dart. I indeed ran a great big about no6 direct from the alternator to the starter relay stud, and went to a voltmeter. In my case there is an easy conversion whereby you can stick a voltmeter into the ammeter's clothing. On mine, normal "key on" "engine off" puts the voltmeter at the first discharge mark left of center, IE it now reads about 12.6V. When the system is running normally, charging at 13.8--14.2V, the voltmeter is now centered, just like the old ammeter used to be. This is occomplished by an adjustment in the meter.

Read this excellent thread over at FABO, it covers some of the A body clusters:

I can't take credit, others came up with this, but I copied it in my 67, and it really works great. I didn't even change the needle. It's a little shorter than the factory pointers.

http://www.forabodiesonly.com/mopar/showthread.php?t=119480&highlight=ammeter+conversion

 

[mjb765]

I have read that in the past...I'm tossing the ammeter in favor of a voltmeter and trying to mount it in the dash.....my question is..can I run the 1 wire alt to the battery stud on the starter realy and power the inside of the car with a direct wire from that stud to the black wires that were on the stock ammeter that feed the dash? Also--I was told with a 140Amp alt I am better off going with 6ga wire and a 10ga fusible link...

 

[Hemi Rebel]

Has anything been added to the car? What all is being driven electrically? Just cause you put a 140 amp alternator on does not mean it will put out that much. If you add up how much current is needed to power all the lights, wipers, heater fan, radio and ignition and whatever else, thats the most it will have to put out.

Never mind. I just went back and read post #7

 

[440roadrunner]

I have read that in the past...I'm tossing the ammeter in favor of a voltmeter and trying to mount it in the dash.....my question is..can I run the 1 wire alt to the battery stud on the starter realy and power the inside of the car with a direct wire from that stud to the black wires that were on the stock ammeter that feed the dash? Also--I was told with a 140Amp alt I am better off going with 6ga wire and a 10ga fusible link...

Basically yes. If you take a look at the simplified diagram in the MAD article it shows the "welded splice." This is where all power comes from inside the car. This is a factory welded splice, taped up in the in--dash harness in the black ammeter wire. It depends on the car, but basically branches off to power

headlights only power

hot buss to the fuse panel

hot feed to the ignition switch


and a couple of other things. Notice that NONE of this is fused, except for the fuse link.

 

[nothingbutdarts]

I have read that in the past...I'm tossing the ammeter in favor of a voltmeter and trying to mount it in the dash.....my question is..can I run the 1 wire alt to the battery stud on the starter realy and power the inside of the car with a direct wire from that stud to the black wires that were on the stock ammeter that feed the dash? Also--I was told with a 140Amp alt I am better off going with 6ga wire and a 10ga fusible link...

I don't think I would run a 6ga or the 10ga. fusable link. I would stick with the 8 gauge output wire and 12 gauge fusable link. Chances are very slim that the alternator will ever put out the full 140 amps. and it would be for such a short time before the regulator would kick the charging amps down much lower to where the 8 gauge wire would not get overloaded. That heavy of wire is kind of overkill, unless you are running LOTS of accessories (lights, blowers, fans, electric defrosters and so on).

 

[bigmanjbmopar]

you must really plan on running a LOT of stuff? I have the 1 wire alt from tuff stuff, love it and I use a volt gauge my amp in dash was disconnected long ago. My alt is a 100 amp and everything runs fine. Unless you are pulling a trailer and planning on powering a remote controlled tv camera I think 100 is fine lol

Good luck let us know how it turns out. And ps I would run a new wire from the battery positive into the car via the bu​lkhead connector

 

[73runner]

connector.

Thanks