1968 Help needed - One Wire Alternator Installation

[di81977]

Been a lot of electric threads lately, thought I would start another. I am in need of some feedback.

A couple years ago, I pulled my 302 out and put in a stroked 351W. The engine takes up a bit more volume in the engine bay than the 302 and has been built for performance. I have always had temperature/heating issues (it can get hot in Colorado in the summer). I tried the following modification:

1) added an electric fan to stock small block radiator
2) replaced small block radiator with a 3+ core big block radiator

Still not happy. I recently heard from a friend that many people who are into hot rods and racing (particularily with blown engines) use either the electric fan from a 92-95 Ford Taurus 3.8L or 95-98 Lincoln Mark VIII. Due to limited front grill openings and air flow, these fans pull in excess of 4,000CFM's. Bad news is that they also take lots of amps to run (particularily at hard start).

Pulled a Taurus fan from the salvage yard ($20) and installed it with only a little trouble (I have a friend who is a wiz at custom fabrication). Drove it about 40 miles in 90+ degree stop and go weather. Temp never got above 200 degrees. Quite happy until I went to restart the car and the battery was dead. Turns out my Alternator can not handle the draw.

Now to my question - I just bought a 140amp single wire alternator. Read lots of threads on the internet on installation, but I am still confused.

Seems pretty straight forward that you run a single fused wire off the alternator to either the pos battery post, starter solenoid, or starter motor relay.

My question is, on our cars, what do you do wth the existing wires, particularily the alternator harness that plugs into the engine compartment wiring harness, connections to the starter motor relay (other than ones going to starter and battery), and the ones plugged into the Alternator Regulator assembly. Can they all be pulled and taped off?

Wiring gets me nervous. My previous experience did not turn out so well!

Thanks in advance for your help.

David

 

[tomcwarren]

Found this in my 'Mustang info' folder:

http://www.mustangmonthly.com/techa...ang_single_wire_alternator_install/index.html

I went with a rebuilt, higher output alternator instead of a 1-wire 3G or 6G swap. Runs my lights, fogs, electric fan, A/C all at the same time just fine. I can find the info on the one I bought if you need it.

Tom

 

[tomcwarren]

more info (on 3G install):

http://www.mercurycougar.net/forums/showthread.php?t=15534

 

[di81977]

Tom, have previously read the first link. Not enough info for a novice like myself. Good read on the 3G from the Cougar forum. After the experiences I have had trying to save money, I decided for $150 to just buy a new one that I know will bolt right in.

Thanks again for the info.

david

 

[di81977]

If anyone is interested - turned out to be a pretty straight forward swap. Only wires that come off are the original alternator wiring harness (from the alternator to the starter relay) and then unplug the connector to the external Alternator regulator. You can then remove the external regulator if you wish. For now, I just taped off the excess wires (might want to go back to stock one day).

I ran 6 gauge wire from the new alternator to a 150amp mega fuse and from the mega fuse to the pos side of the starter relay.

As always seems to be the case, first drive with the new set up the junk yard fan motor died. Not too much of a surprise, as I think part of my problem was a high amp draw for the failing motor.

My $20 junk yard electric fan has turned into a $300 ordeal.