66 mustang ammeter question

enferno

Member
Jun 20, 2006
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i'm rebuilding my harness and my wiring diagram isn't too clear on this - what do the 2 wires of the ammeter connect to? positive side of the starter relay and what does the other connect to?

thanks
 
I believe the wires you're looking for are 654 and 655

66circuit.webp
 

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It goes to wire 37, the black w yellow stripe

and that hooks to the B+ on the alternator.
The "Ammeter" for the '66 is not a traditional Ammeter where it would be in series (IIRC they stopped doing that in the early '60s due to electrical fires under the dash).
This is more a voltage drop/gain reading type of meter, and is therefore placed in parallel. So by hooking one side up almost directly to the battery, and placing the other side on the "use" side of the B+ system, the meter reads voltage drop or gain, and registers it in a graphical user interface fashion as "ammeter".
HTH,
 
In the stock harness, there should be a pigtail connector near the starter soliniod. The other end "should" lead back to the regulater. It should be a yellow wire. I can check my book in the morning at the shop and let you know.
 
and that hooks to the B+ on the alternator.
The "Ammeter" for the '66 is not a traditional Ammeter where it would be in series (IIRC they stopped doing that in the early '60s due to electrical fires under the dash).
This is more a voltage drop/gain reading type of meter, and is therefore placed in parallel. So by hooking one side up almost directly to the battery, and placing the other side on the "use" side of the B+ system, the meter reads voltage drop or gain, and registers it in a graphical user interface fashion as "ammeter".
HTH,

thanks!
 
The 66 AMP meter is a real AMP meter. It needs + or - 750 mA for full defection. It's connected in the wiring harness so that it measures a part of the charging current. This current is determined by the resistance of the meter and the wires.