Chevelles.com banner

1 - 6 of 6 Posts

·
Premium Member
Joined
·
17,409 Posts
Discussion Starter #1
I'd like to put one of the new CS alternators on my 66 Chevelle, but I was reading that you need the factory "alt" or "gen" light hooked up to create enough resistance to excite the alternator (or something like that...

My car has the factory guage package, but the dash harness is a non-guage harness...

Therefore, I don't know what to do... I really don't want to go to a new harness right now (plus I don't know if the factory amp guage works). The fuel guage works, and the oil is mechanical (I have aftermarket water and oil anyway).

I have a wiring diagram, but it only shows the idiot light setup, not the guage wiring (I was going to splice in wires to the guage...).

Does anyone know what I can and should do? Is there a way to wire in some resistance? Can I just mount a bulb in the "alt" light socket (and ground the socket), and then just mount it somewhere out of the way? Will this ad enough resistance?


Also, what would be the correct application for the CS alternator with correct clocking to fit the older Chevelle style brackets?


Thanks

------------------
"Once you go RAT, you never go back..."
TC #1366
Tony
http://www.chevelles.com/showroom/Quik66.jpg
http://www.chevelles.com/showroom/eng7.jpg
 

·
Registered
Joined
·
423 Posts
The "techref" that covers this conversion needs to be updated due to a piece of information from one of the engineers at M&H Electrical (they are the guys that make up most of the quality "factory" style replacement looms sold).

It seems that the factory has a length of wire within the dash loom that provides the required resistance!

As a result, you should be able to just jumper out the bulb and it will work OK. Now keep in mind that I'm talking about doing the jumpering right at the location of the bulb, so that the length of "resistance" wire stays in the circuit.

I've no idea how you would identify the section in question other that to take an OHM meter and read across it (I also don't remember the resistance, but do have it written down somewhere).

------------------
Wes. Vann
Technical Reference section
Gold Member #5
 

·
Registered
Joined
·
659 Posts
I read in a post here a while back that you can convert a 3-wire intrnal reg. alternator to a single wire by putting a jumper across two of the conectors on the alternator.

If this is true, why does the resistance need to be used? Also, I would think that someone would have figured out that you "just need to put a 10Kohm resistor in there", or whatever resistance is required by now.

I am wanting to upgrade my alternator soon, but I want to get rid of my amp gauge and all the extra wire no longer required. I am hoping I won't have to mess with having to leave a lot of old wire in there if it isn't necessary.

------------------
Charles Perrell
[email protected]
65 malibu SS Convertible
283 2v powerglide

[This message has been edited by cperrell (edited 05-14-2002).]
 

·
Registered
Joined
·
1,413 Posts
Wes, the resistance wire is in parallel with the bulb so that the alternator would work if the bulb blows. So, Don't short the bulb but just leave it open.

I would expect that somewhere around 50 ohms would work just fine. It would need to be a 5 watt resistor. This would be equivalent to a 3 watt bulb in the circuit.

The bulb or resistor connects between a switched ignition source and the terminal on the alternator.

Wes, what's with the CS alternators I've seen on 1/2 tons only having the idiot light wire connected while the tech reference shows 2 wire connections? Only 1 wire must be necessary if that's all GM put there.

Peter
 

·
Registered
Joined
·
123 Posts
I have installed GM CS-130 (105 amp) alternators on both of my '65 Chevelles, both cars have with gauges and no idiot lights. On the first car I followed CHP's recommendations and installed an 18 ohm resistor in the wire that feeds current to the alternator when the ignition is turned on. I had to also install a bulb in the circuit to bleed off voltage so that my MSD ignition didn't keep the engine running a few seconds after the key was turned off. On the second car, as advised by an auto electrician, I installed a diode instead of the resistor in order to eliminate the run-on problem. On some CS alternators (I was told) you only need two wires for the factory CS alternators to operate correctly, one 10 gauge or larger to send the charging current to the battery and a smaller 16-18 gauge wire to send current through a resistor to the alternator(if you don't have an idiot light) when the ignition is on.

Rod
 

·
Registered
Joined
·
1,413 Posts
I'm positive you're right Hotrod. Any 88-93 year 1/2 ton's I've looked at only have the main charging wire and the light wire. There is no 3rd connection. I'd like to see some info on what CS alternators, if any, require 3 wires and which ones only require 2.

This year, I looked at one of the truck CS alternators but the SI alternator had a 5 year warranty and was about $60 less. The CS only had a 1 year warranty and needed the pulleys changed.

Peter
 
1 - 6 of 6 Posts
Top