Underhood Ammeter Bypass

James Romano said:
Guys might scream at me for this...but you can use a bolt as well. Tighten the hell out of it and tape it up really well. I have mine like that now, but plan on soldeing them together in the near future
Click to expand...

You CAN even REMOVE BOTH WIRES from under your dash, then run a fresh lead from the big stud on the starter relay to your fuse box and such under the dash. This makes for a shorter, safer path for your main power current to flow through. I did this, with good result. You can also use a fusible link coming off the starter stud to protect this feed, in addition to the links TO the stud from battery/alternator. Overcurrent protection is a MUST! Shortly after buying Mathilda, I had an electrical fire resulting from the alternator shorting to the fender when there were NO fusible links left in the wiring harness at ALL. So it was sadder, and wiser that I learned....

Note, on the heavy current circuits, fusible liks make the best protection available for a reasonable price. Even "slo-blo" fuses seldom will last long enough for certain loads before melting with a startup current load. Breakers have a nasty way of going off at inopportune moments, and one doesn't WANT breakers that WON'T pop under overcurrent! I save breakers for the branch circuits.

I also like using readily detachable connections for ALL my splices. I use split bolts, 3M Scotchlok wire nuts, and yes, bolts and nuts with ring terminals where appropriate. Good stuff, so long as SECURELY fastened for the environment.
 
cbarge said:
At the relay use a fusible link. I used an 18 gauge with my 12 gauge wire.
Fury only has a 38 amp alternator.
On my other car,I am running a 78 amp alternator and used 10 gauge wire with a 14 gauge fusible link.
View attachment 378438
Click to expand...
.Im having a issue with my battery not charging. My ammeter gauge only sits in the middle. I have a 1971 Dodge Polara. I believe the alternator is a 60 amp. What size fusible link should i use an also the wire.
 
Could be your voltage regulator as well.

Did you put a voltmeter on your battery while the car is running? If so, what was the reading? Should be 13.8 or thereabout.

I had the same condition as you and it turned out to be the VR. Swapped it with a new style Electronic, and all was good... but did the bypass anyway.
 
James Romano said:
Could be your voltage regulator as well.

Did you put a voltmeter on your battery while the car is running? If so, what was the reading? Should be 13.8 or thereabout.

I had the same condition as you and it turned out to be the VR. Swapped it with a new style Electronic, and all was good... but did the bypass anyway.
Click to expand...
Its reading 11.6 Volts. I replaced the VR. Maybe the replacement is junk? My ammeter stays in the middle as well. Ive never seen it move around.
 
David1907 said:
.Im having a issue with my battery not charging. My ammeter gauge only sits in the middle. I have a 1971 Dodge Polara. I believe the alternator is a 60 amp. What size fusible link should i use an also the wire.
Click to expand...

I use #8 AWG wire with 6 inches (insulated) of #12AWG fusible link wire for a 60A alternator. I go directly FROM the alternator charging post with an 8 ga Mopar lead, soldered to the #8 wire, which I run AROUND THE FRONT, THROUGH THE RADIATOR HOLDER INSULATED WITH RUBBER GROMMETS, to the fusible link connected to the battery post. I then run a separate lead from the post, to the starting relay on the firewall, which also is protected by a 12 ga fusible link.

The CONVENTIONAL WAY to run this circuit is with #10 AWG run from the alternator post to the starter relay, protecting the circuit with a 14 AWG fusible link at the starting relay. I prefer my way, as the main charging lead for the car has NOTHING else attached to it BUT THE BATTERY, which then feeds the rest of the system.

I advise you to ditch that ammeter connection entirely and to get a voltmeter up near your steering column and attach it to either the fusebox or further back at the starter relay stud. From what you've reported, I suspect your ammeter or the lead to it is burnt in two. Chase that black ammeter wire down and disconnect it at both ends if not pulling it clean out! Do that FIRST before anything else. You'll be SO GLAD YOU DID!
 
David1907 said:
Its reading 11.6 Volts. I replaced the VR. Maybe the replacement is junk? My ammeter stays in the middle as well. Ive never seen it move around.
Click to expand...

Your ammeter is still connected to the BATTERY, which is GOING DOWN. You MIGHT at THIS point, check the ALTERNATOR TOO to make SURE its not fried. You CAN direct wire the field for a SHORT period, to see if the thing is charging. Bypass the VR and connect the field direct to what battery you have, then crank up and see what the system voltage is when you START, then 5 minutes later. THAT should more than suffice to test the alternator. You MAY want to FUSE the TEMPORARY connection directly to your field. Your Alternator is a squareback, isn't it? If so, GROUND the second field connection and hot feed the first for the test.
 
Gerald Morris said:
Your ammeter is still connected to the BATTERY, which is GOING DOWN. You MIGHT at THIS point, check the ALTERNATOR TOO to make SURE its not fried. You CAN direct wire the field for a SHORT period, to see if the thing is charging. Bypass the VR and connect the field direct to what battery you have, then crank up and see what the system voltage is when you START, then 5 minutes later. THAT should more than suffice to test the alternator. You MAY want to FUSE the TEMPORARY connection directly to your field. Your Alternator is a squareback, isn't it? If so, GROUND the second field connection and hot feed the first for the test.
Click to expand...
I did this as well on mine to find it was a bad VR. Just don't rev the motor too high as it won't regulate. The alt will just keep hammering out V/A unguarded the faster you rev
 
David1907 said:
Its reading 11.6 Volts. I replaced the VR. Maybe the replacement is junk? My ammeter stays in the middle as well. Ive never seen it move around.
Click to expand...
Have you looked under your dash to see if someone didn’t already connect them together taking the ammeter out of play?Red and Black wire connected together?
 
David1907 said:
.Im having a issue with my battery not charging. My ammeter gauge only sits in the middle. I have a 1971 Dodge Polara. I believe the alternator is a 60 amp. What size fusible link should i use an also the wire.
Click to expand...
10 gauge main wire and 14 gauge fusible link.
The ammeter will not read accurately after the bypass.
Use a multimeter at the battery with engine running to checkl voltage output from the alternator as process of eleimintion..
Pull a field wire off the back of alternator to siulate a full charge situation. If the voltage increases replace volatage regulator.
If voltage does not increase and hovers at or below 12 volts replace alternator.
 
cbarge said:
10 gauge main wire and 14 gauge fusible link.
The ammeter will not read accurately after the bypass.
Use a multimeter at the battery with engine running to checkl voltage output from the alternator as process of eleimintion..
Pull a field wire off the back of alternator to siulate a full charge situation. If the voltage increases replace volatage regulator.
If voltage does not increase and hovers at or below 12 volts replace alternator.
Click to expand...

I unhooked the voltages regulator. And the voltage did not go up.
 
HWYCRZR said:
Have you looked under your dash to see if someone didn’t already connect them together taking the ammeter out of play?Red and Black wire connected together?
Click to expand...
Your saying someone could of put those wires together. Making it inoperable.
 
Ammeter Question: What year did it stop carrying full charge from alternator?
Just for clarification,
1970 Fury: ammeter has 10 gauge wires both sides and carries full charging amperage.
By contrast,
1972 Fury: ammeter has 20 gauge wires and does not carry full current. The ammeter provides an indication of current flow, but (shorted, open, or normal) if it stops working the car will not stop running.
Was 1971 the last year that full charging amperage ran through the ammeter? Thanks, Ben
1972 Fury: Immune to Death by Ammeter
IMG_20200828_141542 ps.jpg
 
Chrysler knew about the "flaw" for years.
That's why all the police pursuit cars had their own H.D. shunt or bypass.
My 73 Satellite wagon has a factory shunt too.
By 1974 when the newly designed Formals came along the wiring was also redesigned and the gauge acts as a voltimeter.
The B bodies for 75 got the redesign and the F bodies in 76.
A bodies trudged along since the F replaced it.
 
I forgot about MyMopar - Mopar Forums & Information - Service Manuals. Thanks @Davea Lux
Downloaded 1971 shop manuals
Looks like 1970 was last year for full current through the ammeter and thus last year for "found on road dead" if ammeter melts down.
1971 Factory Shop Manual Fury Instrument Panel Wiring Diagram
Ammeter Wires are 18 gauge, not 10 gauge, and can't carry/don't carry full alternator current.
Ammeter.jpg

1970 Factory Shop Manual Fury Instrument Panel Wiring Diagram
Ammeter Wires 10 gauge and carry all alternator output. If ammeter breaks down, car breaks down.
Ammeter.jpg

I need to do some additional wiring off alternator for 1970 Fury III Convertible
IMG_20201008_175219.jpg
 
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