Amp Gauge and Temp Gauge Wiring - 71 Javelin

I do not have a 71 TSM but the 72 TSM shows the rally gauge wiring circuits on page 3-37 of the electrical section.   For the Ammeter, you should have a Splice into the fusable link connected between the red wire off of the same terminal of the starter relay that accept the +battery cable and the pink wire to the horn relay.  That spliced wire will be black and to the the + terminal of the ammeter.  The ammeter ground _  (neg) terminal has a red wire going to the BAT terminal of the alternator.  

Any idea what gauge wire should the black and red wires should be for the ammeter? Also, what kind of fuse should I use in the link to the starter relay?

I think the connections are oem. I'm not certain though because I'm not familiar with the wiring on it. Any ideas where I find a TSM?

One thing I'll add to this just as a word of caution - if your alternator is larger than stock (amperage wise) don't hook that ammeter up or you can possibly burn it up. I've seen several cars over the years that had dash fires from large alternators burning up the ammeters. Most rebuilt over-the-counter alternators have the output increased by the re builder which is higher than the ammeters can handle so they get real hot and start melting things.

The worst one that I've seen was at the Mopar Nationals years ago. A freshly restored '69 Roadrunner was running on the guys trailer while he was untying it when the dash started smoking bad. It literally caught fire and several people with extinguishers managed to put it out after a quick thinking guy yanked the battery cable off of the battery and pulled the coil wire. What a nightmare it was because the car had white interior that was badly smoke damaged. His low battery and shiny, chrome, 130 amp Powermaster alternator were the bad guys. After it was was all said and done, the owner sat there and cried. After he got himself together, he took off for home - 3 states away. I'll never forget that one. It makes me thinking of it again.