Install a GM "3 wire" alternator on an R1 Avanti

[sbca96]

UPDATE per picture location change - 3/14/09

I got an email today asking me where I got the bracket to install the
GM alternator on my R1 Avanti. I figure I might as well post the info
here for all to benefit.

The install was simple, I used a standard three wire GM alternator, it
gets mounted upside down (the alternator wont care). I had to redrill
two holes, the R1 bracket is two pieces. I unbolted the 3 bolts that
hold the small bracket to the large bracket, and moved the bracket to
the front. Basically the front hole becomes the rear hole. Than I
drilled two holes the same size as the others and remounted the small
bracket in the forward pattern. I dont recall having to bend the arm
on the bottom, but the pulley should live up fine in this location. I
think the wiring details were on Bob Johnstone's, but the Honda alt
page has been redone, and my old GM alternator tech is now gone. Bob
you still have that somewhere? Here are pictures :

















Tom

'63 Avanti, zinc plated drilled & slotted 03 Mustang Cobra 13" front disc/98 GT rear brakes, 03 Cobra 17" wheels, GM alt, 97 Z28 leather seats, soon: 97 Z28 T-56 6-spd, Ported heads w/SST full flow valves, 'R3' 276 cam, Edelbrock AFB Carb, GM HEI distributor, 8.8mm plug wires

[64V-K7]

The above sequence is online now, at

http://www.studebaker-info.org/tech/Alternator/delco10si/r1avanti/r1avdelcoalt.html

Thanks Tom..

Bob Johnstone

[DEEPNHOCK]

Does your 1 wire charge at idle after you first start it up, or do you have to rev it up to 1500 rpm or so to excite the field?
(an issue with most one wire installs)..
Some people I know just put a 194 bulb under the dash and color it black with a Magic-Marker so the draw will excite the field.
Just curious as to what your experience was.
Jeff[8D]

quote:Originally posted by sbca96

I got an email today asking me where I got the bracket to install the GM alternator on my R1 Avanti. I figure I might as well post the info
here for all to benefit.

DEEPNHOCK at Gmail.com
Brooklet, Georgia
'37 Coupe Express (never ending project)
'37 Coupe Express Trailer (project)
'61 Hawk (project)
http://community.webshots.com/user/deepnhock

[lstude]

I have installed a GM one wire alternator on the 64 289 engine in my 52 Commander. I bought the bracket from Dave Thibeault. I haven't wired it yet, but I was told that the one wire goes to the amp gauge and then to the positive post of the battery. I was planing on putting it on the starter Solenoid where the positive battery cable is attached. Is this correct? Here are some photos.






Leonard Shepherd, editor, The Commanding Leader, Central Virginia Chapter, http://centralvirginiachapter.org/

[sbca96]

That bracket looks bent down in front putting the alt at an angle to
the crank hub. Maybe its an optical illusion?? Make sure the pulley
is true to the crank. My install works fine at idle, charges right at
startup, never noticed a problem. Maybe my R1 revs higher when it is
started, I really never paid attention - certainly not 1500 rpm. It
was late last night when I finally got around to entering this post,
I CAN get some MUCH better pictures, and will probably replace these
on my FTP later. I took these for an Avanti Magazine article I did a
few years ago, my digital camera sucked. I can go out and write down
the wiring sometime this weekend.

Tom

[Dick Steinkamp]

That should work fine, Len.

Some may not like all that electricity going to the ammeter then back to the battery, but if you use some heavy wire, you should be OK. That's how I wired my Starliner and it's working great after 6 years and 30,000 miles. You may want to put a fuseable link at the alternator just to be on the safe side (I didn't)

[lstude]

quote: That bracket looks bent down in front putting the alt at an angle to
the crank hub. Maybe its an optical illusion??

I don't know why it looks bent in the picture. It isn't. It seems true to the pulley. Thanks for the advice, Dick. If it works for you it's gotta work for me.

Leonard Shepherd, editor, The Commanding Leader, Central Virginia Chapter, http://centralvirginiachapter.org/

[Dick Steinkamp]

Ya know...my one wire alternator has one wire. SBCA'a looks like it's got 4 and Len's looks like it's got 3.

What's with that?

[sbca96]

I would be more than happy to go out and write down what I did, but at
the moment I am at work - 55 miles away from the Avanti.[:I]

Tom

quote:Originally posted by lstude

I don't know why it looks bent in the picture. It isn't. It seems true to the pulley. I would like some help with the wiring.

[sbca96]

Each wire is only one wire ... right?

In my pictures one of the two wires in the plug is not used, I think
its the white one. One is the ground wire that already existed in
the wiring harness, which now goes to the ground wire that used to
be attached on the base of the voltage regulator. I believe thats
the one going to the bolt boss at the bottom. The wire going to the
top nut/shaft is the positive voltage. This is all from memory so
take it with caution until I can verify!!

Tom

quote:Originally posted by Dick Steinkamp

SBCA'a looks like it's got 4 and Len's looks like it's got 3.

[lstude]

Thanks, wiring help would be good. I questioned the guy at NAPA about the wires also since they call this a one wire alternator. He said that it is a one wire for the car, but that other wire with the plug has to be connected to the terminal. I can't remember the reason because I am electrically challenged I took that plug from an old GM alternator that came off of an 85 Buick Regal.

Leonard Shepherd, editor, The Commanding Leader, Central Virginia Chapter, http://centralvirginiachapter.org/

[Dick Steinkamp]

A GM one wire alternator has only one wire...the heavy wire from the post in the rear of the alternator. It will not have the plug in the side with the two wires leading out of it.

SBCA and Len, I don't believe you have "one wire" alternators.

SBCA that is probably why yours charges immediately after start up. A one wire GM alternator will need to "see" about 1500 engine RPM's in order to self excite. A normal 3 wire GM alternator will get battery voltage on start up (from one of the two wires in the plug) and charge immediately. The wire you didn't use is probably the one that would normally go to the idiot light. It would be interesting to know how you have it wired. A one wire alternator has just the one wire and it goes to the battery (or through the ammeter if so equipped).

Len, are you SURE that's a one wire alternator? If so, someone removed the plug and inserted that harness in error.

[Dick Steinkamp]

quote:Originally posted by lstude

Thanks, wiring help would be good. I questioned the guy at NAPA about the wires also since they call this a one wire alternator. He said that it is a one wire for the car, but that other wire with the plug has to be connected to the terminal.

It's not a one wire alternator. If you want a one wire alternator take it back and exchange it for one. One wire alternators are not used on any production cars. They are an aftermarket product (hot rod). You can kind of fake it with that one by connecting the field wire on that two prong plug to the output of the alternator (I think).

[lstude]

quote:Len, are you SURE that's a one wire alternator? If so, someone removed the plug and inserted that harness in error.

I'm not sure of anything at this point.[], but the guy at NAPA told me it was and my friend Tom Covington also told me it was. Tom has one wire alternators on his Studebakers. Tom also told me that I needed that wire from the plug connected, but I still can't remember why.

I wired my house and garage, but car wiring mystifies me

[64V-K7]

The wiring for a Delco 10Si can be setup, using 1 wire or 3 wire, all pretty simple. The one wire setup really uses 2 wires, the BAT and T2. They call it one wire because only one wire leaves the alternator.

The BAT terminal always (in my experience) goes to the starter solenoid junction, to provide power to charge the battery and run the power buss. You don't have to run it to the ammeter.

The T2 is the exciter wire and can either go to only the BAT terminal (short length), which is defined as the one wire setup OR it can be attached to somewhere under the dash to better sense the voltage draw on the circuits. If you attach this to the BAT terminal, you can ( but not always) get a reaction as described as above, where you have to rev the engine to get it to start charging. If T2 is attached to the BAT terminal, even if it charges immediately, you may not always have the correct amount of voltage being supplied by the alternator to satisfy the buss requirements.
If T2 is attached under the dash, it will almost always charge from startup and at idle and supply the correct voltage for the draw on the buss.

The T1 can be attached to an idiot light to indicate a state of charge. It must be run to one side of the light and the other side of the light, to a switched power source. So, you have two 12V sources at the light. When both are active the light will not be on. If the Alternator stops charging, then the T1 field is grounded and the 12V flows, lighting the bulb.

One thing to consider, since most Delco alternators have a higher output, is to increase the gauge of the wire from the solenoid junction to the buss connection and to make an additional fused circuit to handle any additional power goodies you may add.

Bob Johnstone