Early Bronco Alternator Wiring (simplified)
http://classicbroncos.com/forums/showthread.php?t=176046SEE THE NEXT FEW PICS & CAPTIONS...
If there are no new loads, then the only load thru the original ammeter wire is the battery charging load, which is the same as with the stock alternator, and it should never go over 60A.
But if there IS an extra load at the battery (at the frowny, like a winch, amplifier, inverter...), then the original ammeter wire has to be either upgraded to handle the entire alternator output (with some safety margin) since it could conceivably carry that much when the engine is running, OR the alternator output can simply be connected directly to the starter relay, with the battery wire. If the new loads are attached at the fuse block (the smiley), the stock ammeter wire, the fusible link, & the rest of that circuit must be upgraded. This shows the LEAST-destructive result of NOT upgrading it:
It COULD have resulted in a fire in the dash.
130amp (2 holes between each pair of front ribs) Donors:
'94-95 Mustang 5.0L
'94-00 Mustang 3.8L
'94-97 Thunderbird/Cougar 3.8L
'90-95 Taurus/Sable 3.8L
'93-99 Taurus/Sable 3.0L
'95-98 Windstar 3.8L/3.0L
'91-94 Lincoln Continental 3.8L
'92-97 F-series (optional)
'92-96 E-series (optional)
There are at least 3 mounting bolt configurations among those, so check your mounting bracket carefully.
To add the voltmeter, read these captions:
This diagram was created from this set of symbols using MSPaint:
See also:
.
.
.
.
https://www.fleet.ford.com/truckbbas/non-html/1997/c37_39_p.pdf 
![wiringdiagrameb3g.jpg Early Bronco Alternator Wiring (simplified)
http://classicbroncos.com/forums/showthread.php?t=176046
SEE THE NEXT FEW PICS & CAPTIONS...
If there are no new loads, then the only load thru the original ammeter wire is the battery charging load, which is the same as with the stock alternator, and it should never go over 60A.
But if there IS an extra load at the battery (at the frowny, like a winch, amplifier, inverter...), then the original ammeter wire has to be either upgraded to handle the entire alternator output (with some safety margin) since it could conceivably carry that much when the engine is running, OR the alternator output can simply be connected directly to the starter relay, with the battery wire. If the new loads are attached at the fuse block (the smiley), the stock ammeter wire, the fusible link, & the rest of that circuit must be upgraded. This shows the LEAST-destructive result of NOT upgrading it:
[url=http://www.supermotors.net/registry/media/910361][img]http://www.supermotors.net/getfile/910361/thumbnail/ammeterconn.jpg[/img][/url]
It COULD have resulted in a fire in the dash.
130amp (2 holes between each pair of front ribs) Donors:
'94-95 Mustang 5.0L
'94-00 Mustang 3.8L
'94-97 Thunderbird/Cougar 3.8L
'90-95 Taurus/Sable 3.8L
'93-99 Taurus/Sable 3.0L
'95-98 Windstar 3.8L/3.0L
'91-94 Lincoln Continental 3.8L
'92-97 F-series (optional)
'92-96 E-series (optional)
There are at least 3 mounting bolt configurations among those, so check your mounting bracket carefully.
To add the voltmeter, read these captions:
[url=http://www.supermotors.net/registry/3536/69567-4][img]http://www.supermotors.net/getfile/900916/thumbnail/voltmeter10.jpg[/img][/url]
This diagram was created from this set of symbols using MSPaint:
[url=http://www.supermotors.net/registry/media/858661][img]http://www.supermotors.net/getfile/858661/thumbnail/wiringsymbols.gif[/img][/url]
See also:
[url=http://www.supermotors.net/registry/media/870470][img]http://www.supermotors.net/getfile/870470/thumbnail/3gswap.jpg[/img][/url] . [url=http://www.supermotors.net/registry/media/843907][img]http://www.supermotors.net/getfile/843907/thumbnail/alternator3gvr.jpg[/img][/url] . [url=http://www.supermotors.net/registry/media/849725][img]http://www.supermotors.net/getfile/849725/thumbnail/fusesblades.jpg[/img][/url] . [url=http://www.supermotors.net/registry/media/830776][img]http://www.supermotors.net/getfile/830776/thumbnail/fusiblelinkrepair.jpg[/img][/url] . [url=http://www.supermotors.net/registry/media/832986][img]http://www.supermotors.net/getfile/832986/thumbnail/bulbsfuseswire.jpg[/img][/url]
https://www.fleet.ford.com/truckbbas/non-html/1997/c37_39_p.pdf](https://www.supermotors.net/getfile/843356/fullsize/wiringdiagrameb3g.jpg)