87 GT 3G alernator conversion

d_gtracer

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Oct 25, 2005
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87 GT 3G alternator conversion

Can someone tell me what alternator, any special brackets, and any special plugs needed to change the alternator in my 87GT to a 100AMP (3G) conversion. Not sure what info to post other than year of my car. Am new to StangNet and thanks for any help .
 
You'll need the alt, a wiring harness, and you'll need to grind down the inside corner ofthe alternator bracket. For specifics, check here: http://www.fordmuscle.com/archives/2001/03/paperformance/index2.shtml

Following the guidance on the website for hooking the black/orange wires up to the 3g alt is not recommended. Use PA-Performance wiring upgrade or constuct a harness of your own out of 4 gauge wire and terminal ends. Leave the black/orange wires disconnected. The new wriing harness will run from the power terminal on the alt to the unswitched side of the fender mounted starter solenoid.
 
ok, heres a simplified version of wat to do. mount the alt. but grind away at the bracket as needed to fit the alt. the oval looking connector, leave it alone. snip the square lookin connector off (2 black/orange wires, 1 white wire). you can trace the black/orange ones back to where the split into two and cut them there and tape it off. youll notice the white wire leaator ds to the oval connector strip and solder (or some sort of connector dont just splice) the stator wire onto the existing white wire. ( the stator wire is the single white wire off your original 3g alt. wiring. it have a single gray connector at the end, you need to attach this connector to your fox wiring whit wire. there the same color, its EASY) no tape up the wiring, connect it to the alt and add wire loom if you wish (helps witht he heat depending how its routed. now, attach your power wire to the little copper stud on the back of the alt to the positive battery cable side of the starter solenoid.( the power wire is VERY important. many companies make them specifically for this reason, PAPerformance.com sells a great one. you need AT LEAST 4 Ga wire (same as battery cables) it must be long enough to reach from the starter solenoid to the back of the alt and the connectors on the ends must be the right size ( to fit each stud) and connected properly. you can also just get the lenth and have a car audio place make the wire for you. the stud on the starter solenoid is 1/2" and on the back of the alt is 5/16s i believe.) then check all your hookups, and turn on the car and make sure everyhitng is fine, you def dont want a fire! again, this is the cliff notes version of the swap, it is much easier this way but only if you kno all of the parts needed for the swap.
 
See WWW.partsexpress.com for the fuse & fuse holder.
Fuse @ $3.90 each (need one) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=071-952

Fuseholder @ $5.80 each (need one) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=263-630

4 gauge black wire @ $1.25 a foot (use string to lay out routing & determine length) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=100-196

4 gauge red wire @ $1.25 a foot (use string to lay out routing & determine length) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=100-194

4 gauge ring crimp terminals (package of 5) $3.25. http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=095-584

Don’t forget the alternator power ground!!!
The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges. Any car that has a 3G alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects.
 
here is a wiring diagram of what to do. also need to add the 4 awg wire as well. and a pic of what area to grind on the bracket.

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