Ammeter wiring

[PES]

I am having difficulty figuring out the proper wiring of the ammeter on my stock '59 3b, with generator.  It had the ammeter and oil pressure gauges (Stewart Warner) mounted in the dash to the right of the speedometer that appeared to be original or a very clean owner installation.  I had to replace the tub a few decades ago and was careful in marking things - but who knows.  It worked well for a long time but after 8 months in storage I had a number of issues to address, in part due to the ammeter to ignition wire separating.

The factory manual wiring diagram (12v) does not address its connections. Currently it is connected to the battery side of the starter solenoid and then from the other ammeter post to the Bat. terminal of the ignition switch. The ignition switch has a separate battery line coming in to the Bat terminal. When I turn on the headlights it reads +, which it did not do before.  When I look at other's wiring diagrams that include ammeters I see it connected to the Bat terminal of the regulator or in one where the second terminal was connected to the + side of the battery or in other cases to the generator.

I am trying to track things using a Fluke on continuity settings but my skills here are limited.  Does the second battery connection to the ignition switch mean the ammeter reading will be incorrect?   Given it seems to read backward, can I reverse the connections on the back of the ammeter to get a proper reading?  I am tempted to disconnect it (as long as I can stall start it) and rely on the light in the speedometer and a more recent voltmeter.  I just need some means to be sure it is charging, aside from getting a dead battery in the middle of nowhere.

Thanks for suggestions,  Paul

[Rus Curtis]

... stock '59 3b, with generator.  It had the ammeter and oil pressure gauges (Stewart Warner) mounted in the dash to the right of the speedometer that appeared to be original or a very clean owner installation.... It worked well for a long time but after 8 months in storage I had a number of issues to address, in part due to the ammeter to ignition wire separating.

....The factory manual wiring diagram (12v) does not address its connections....


...Currently it is connected to the battery side of the starter solenoid and then from the other ammeter post to the Bat. terminal of the ignition switch....


... When I look at other's wiring diagrams that include ammeters I see it connected to the Bat terminal of the regulator or in one where the second terminal was connected to the + side of the battery or in other cases to the generator....

...Given it seems to read backward, can I reverse the connections on the back of the ammeter to get a proper reading?.... 

... disconnect it (as long as I can stall start it) and rely on the light in the speedometer and a more recent voltmeter..... 


Thanks for suggestions,  Paul

So many questions.  Understand, I'm not an expert and surely smarter folks will chime in, but I'll help as much as I can.  I think more information is needed.

You say 12V generator with an ammeter.  Then you mention you have a light on the speedometer (idiot light?) and you have a voltmeter.  That's 3 different devices telling you the same thing. What gauges are you using separate or cluster or some kind of mix? 

You had one wire that separated on you (found after storage), but the ammeter was working before that.  If you replaced that one wire "ammeter to ignition wire" then it should still be working.  Did you replace/ remove and reconnect other wires?

Having one terminal of the ammeter tracing back to the solenoid/batt and the other terminal on the batt (hot) term of the ignition switch.  To me, that sounds like both terminals are connected to the + batt post with no ability for electricity to flow through the gauge.

You mention factory wiring diagram (I'm guessing Fig. 144 in the Service Manual since you mentioned 12V) it doesn't show an ammeter (has large instrument cluster).  Older 6V diagrams (separate gauges) show the ammeter hooked up to the starter switch/horn (battery side) and the other terminal has only the regulator and ignition switch.

[PES]

The 6v setup sounds similar and I have attached a schematic as mine is currently set.  I just finished some needed maintenance (radiator, steering box and drag link) and have to get it inspected due to a move.  I noticed the lights were very dim and was sorting that out.  While it remains a mystery, there was no power fro the ignition switch to the light switch.  I also found a short that may explain a slow drain. So there were multiple issues which may be confusing me and my trouble shooting.

I ran a line from the Ign. lead on the ignition switch to the light switch and they now appear to be working.  I fixed the bare wire short. 

It appears though that all power aside to the starter passes through the ammeter as I tried to disconnect it to take it out of the loop and had no power at all.  This is a stock Jeep.

So far, no smoke, no arcing so I think things have progressed.

The ammeter never read backward and I suppose there is a remote chance the connections on the back were reversed.  I don't understand the purpose of the Bat connection on the regulator and it is not explained in the factory manual but the wiring path appears to be connected as shown in Fig 144 of their manual. 

I am inclined to switch the wires on the back of the ammeter and see what happens.

[SteveKfl]

I'm certainly "not smarter" or "more experienced" than Rus, but I did want to make a point, or two, of distinction.  One, the "ammeter" is placed "in the flow of energy" to monitor "AMPS/HEAT".  Two, the "12V bulb" (won't light if not enough voltage for it) and the "volt meter" monitor the "voltage" of the battery/system, wired in parallel to ground, not INLINE VOLTS.  The FLD on the regulator monitors the "voltage status" (to regulate the charging system) while "BAT" is the "BATTERY SOURCE" line.  Attached is a wiring diagram I have to try to help show some of the hook ups.  I hope it helps.  Good Luck!  Please keep us posted of findings.  Thanks.

[Rus Curtis]

Like Steve mentions, the ammeter measures flow and is inline or series with the connections.  A voltmeter measures pressure and will be connected parallel.

Using both diagrams (yours and Steves) you can see power through the ammeter back to the solenoid post.  The "flow" after the meter goes to the ignition switch then back to the solenoid.  If you disconnect the ammeter, you've disconnected the solenoid from the starting circuit. 

When I am faced with multiple issues as you've described, I take a pause.  Step back and begin a very systematic trace from the battery through each component.  This eliminates "fixing" one issue while creating 3 more issues.  Check each fix and be deliberate.