Another GM Alternator Conversion
- Thread starter socalx19
- Start date
lookforjoe
True Classic
The only change is the short wire you had previously connected from (bat) terminal on alt to #2 terminal on alt is now a wire all the way to the starter? If that is so, then the wire you made previously (shown in your pic below) must have had no continuity - there is no other explanation. Did you check the wire with your multimeter for continuity?
Did you also check the existing wire from starter to alt for continuity?
Did you also check the existing wire from starter to alt for continuity?
jvandyke
True Classic
What's difference between running the #2 wire to the alt's own lug, the starter or the battery, they are all connected right to each other anyway, no? I agree with Hussein, your little wire must have bad connections since the above path is all the same circuit.
How does your charge light still work if #1 wire isn't connected anymore?
How does your charge light still work if #1 wire isn't connected anymore?
socalx19
True Classic
Yup, both wires check out fine. I don't get it either.
socalx19
True Classic
I don't really get it, but #1 is still connected to the black/purple wire and appears to be working properly. So the only difference is running #2 straight to the battery (I will actually add it to the terminal "hub" in the fuse box).
lookforjoe
True Classic
Can you be more specific? What was the resistance values from terminal to terminal of each cable in question? The problem here is that just moving the #2 wire from (bat) on alt to actual battery should not have made any difference.
The fact that it did suggests the other cable is not good. What is of concern is that you could have an electrical fire (!!!) if the only charging wire is now the little one you added from alt to bat.
socalx19
True Classic
I've decided to re-do this.....
After seeing the 14.5v drop to 14v, I began researching this wiring more and came across this (I have the 12SI alt):
http://bob_skelly.home.comcast.net/~bob_skelly/alternator_conversion/wiring_alternator1.html
It suggests that:
[FONT=Arial, Helvetica, sans-serif][FONT="]"It is better to run the sense wire away from the alternator and over to the power terminal post near the battery. This will ensure that the system voltage is properly maintained."
[/FONT][/FONT]
So, I have decided not to jumper #2 to the BAT on the alternator but instead, run 8ga wire to the terminal "junction" in the fuse box. Doing so, I get 14.6v at the battery. At the same time, I've ripped out the brown wire and brown wire mod, replacing those 2 wires with a single 4ga wire.
After seeing the 14.5v drop to 14v, I began researching this wiring more and came across this (I have the 12SI alt):
http://bob_skelly.home.comcast.net/~bob_skelly/alternator_conversion/wiring_alternator1.html
It suggests that:
[FONT=Arial, Helvetica, sans-serif][FONT="]"It is better to run the sense wire away from the alternator and over to the power terminal post near the battery. This will ensure that the system voltage is properly maintained."
[/FONT][/FONT]
So, I have decided not to jumper #2 to the BAT on the alternator but instead, run 8ga wire to the terminal "junction" in the fuse box. Doing so, I get 14.6v at the battery. At the same time, I've ripped out the brown wire and brown wire mod, replacing those 2 wires with a single 4ga wire.
Black-Tooth
Tony Natoli
Gonna start calling you Rudy Brown pretty soon...
WOW...
What a terrible trouble to shoot! Ya done gud!
WOW...
What a terrible trouble to shoot! Ya done gud!
bikesandcars
True Classic
the purposes of that number 2 wire ( as you have discovered ) is to overcome vehicle voltage shortcomings at the dash (or wherever else needed) due to electrical loss through the system. You basically put that wire where you NEED 14.4 volts and the alternator will generate more than 14.4 to generate 14.4 at the number 2
. In most situations short-wiring that lead to the alternator provides enough voltage within a reasonable value. It seemed to me above that your number 1 wasn't wired right because it wasn't shown in the pic... but apparently the problem was your battery wasn't connected through the starter. Is that correct?
IF you have short-wired the alternator and are getting 14.4 at the alternator but 14 at the battery, you probably need to clean connectors somewhere (starter) or terminals, that's a lot of loss for a short distance.
I'm not 100% sure (even after installing one of these) but it seems that number 2 runs the regulator, and number 1 provides the field (switched) for the alternator to make power. IF you leave number 1 on you will slowly drain your battery and in some cases the alternator will continue to power ancillary components such as ignition (depending on custom wiring).
socalx19
True Classic
Now the real test is to take the charge indicator bulb out of its socket and see if it still charges, I don't think we ever settled that debate did we?
Confirmed - removing the bulb drops the reading to 12.0v and no charging. Put it back in, 14.6v and charging when switching accessories on.
Yes, #1 was connected to the black/purple wire, using the original connector that went to the OE alternator (it's visible here - the white connector):
What I noticed when I crawled under the car was a spade connector hanging off where it should be connected at the starter. I believe this is for the ignition switch? There is still another wire from the starter to the battery (4ga?) which has a solid connection at both points. I measure 14.6v in this wire now.
I cleaned up A LOT, but I'm sure it could use more. It seems that either the wire from the starter to the battery is suspect (even with now measuring 14.6v?) OR there is something different about this alternator that doesn't like having #2 jumpered to BAT.
geekdaddy
X1/9 Learner's Permit...
Is it necessary to run a heavy gauge (8) wire on the sense line from the alternator to the junction block? If the current is low, the voltage drop would be low as well. Does the sense line draw much current?
