alternator question

river1 · July 17, 2006, 06:56:43 PM

the bolt that is indicated by the black tool handle in the pic below.

is the bolt a ground or just a mounting bolt or both?

thanks to the RRT brain trust

later jim

Fat Cat · July 17, 2006, 07:42:24 PM

Quote from: "river1"the bolt that is indicated by the black tool handle in the pic below.

is the bolt a ground or just a mounting bolt or both?

thanks to the RRT brain trust

later jim

I have seen it used more often for mounting. Only times I have seen it used for grounding is on glass cars.

river1 · July 17, 2006, 08:34:54 PM

thanks frank

EMSjunkie · July 17, 2006, 08:56:33 PM

I often wondered about that bolt too :?

thanks for the info.

Vance

BFS57 · July 19, 2006, 02:05:54 PM

Hello;
I see by the photo that you have two wires coming from the output and that the two wire (making it a 3 wire) hook up isn't used. I am in the need to change my externally regulated alternator for a "one wire" alt. But wait a minute! I guess I have read too many views on how to hook this kind of alternator up (properly?).
I looked at the MAD Enterprises web site and got some pretty good ideas on just how to do this. First is to hook up the single wire to the battery, then run a small lead from the battery lead on the alternator to the #2 post on the alternator. Next you run a wire from the #1 post to a light socket (with a light bulb in it) and in turn run the other wire from the light socket to a switched power from the ignition. This does two things, gives you an "idiot" light (that will let you know of problems) as well as excites the internal regulator.
Whats the general view of hooking a "single" Wire alternator up? After I read more from the MAD site I had a different point of view on the subject not to mention a couple wiring "tricks" to make any wiring job easier as well making it simple to ad anything needed (with ease) down the road.

Bruce

Dave · July 19, 2006, 02:14:39 PM

Quote from: "BFS57"Hello;
I see by the photo that you have two wires coming from the output and that the two wire (making it a 3 wire) hook up isn't used. I am in the need to change my externally regulated alternator for a "one wire" alt. But wait a minute! I guess I have read too many views on how to hook this kind of alternator up (properly?).
I looked at the MAD Enterprises web site and got some pretty good ideas on just how to do this. First is to hook up the single wire to the battery, then run a small lead from the battery lead on the alternator to the #2 post on the alternator. Next you run a wire from the #1 post to a light socket (with a light bulb in it) and in turn run the other wire from the light socket to a switched power from the ignition. This does two things, gives you an "idiot" light (that will let you know of problems) as well as excites the internal regulator.
Whats the general view of hooking a "single" Wire alternator up? After I read more from the MAD site I had a different point of view on the subject not to mention a couple wiring "tricks" to make any wiring job easier as well making it simple to ad anything needed (with ease) down the road.

Bruce

Ive got a 1 wire that can also be hooked up as a 3 wire and ive been thinking of doing that cause when the car is warm and you start it unless you give it enuff rpm the thing doesnt start charging. The cure is a 3 wire hookup and that will make it charge soon as the engine starts.
Dave

model a vette · July 19, 2006, 03:11:45 PM

On Chevys starting in '69, with the use of long water pumps, that bolt was used to help secure a long spacer that went on the pivot bolt. The long spacer had a tab that bolted to that hole.

enjenjo · July 19, 2006, 04:18:31 PM

Not all internally regulated GM alternators can be hooked up with only one wire, only the ones that have been fitted with the proper regulator, originally used in marine applications. And yes, you have to rev the engine up once to make it charge.

On a standard three wire, you can hook a wire from the battery post to the number 2 terminal, and it will work, although I no longer do it that way, and I'll tell you why. The number 2 terminal sets the system voltage, and by hooking it directly to the battery, it senses battery voltage, instead of the system voltage inside the car. So even though the alternator may be seeing 12.8 volts at the battery, you may only have 11.8 inside the car. So you are better off hooking that wire to the battery side of the fuse block, or ignition switch, to get proper charge voltage.

The number 1 terminal is hooked to a light, or the ignition switch through a diode or relay, to excite the charging circuit.

Jokester · July 20, 2006, 12:45:45 AM

Quote from: "enjenjo"

On a standard three wire, you can hook a wire from the battery post to the number 2 terminal, and it will work, although I no longer do it that way, and I'll tell you why. The number 2 terminal sets the system voltage, and by hooking it directly to the battery, it senses battery voltage, instead of the system voltage inside the car. So even though the alternator may be seeing 12.8 volts at the battery, you may only have 11.8 inside the car. So you are better off hooking that wire to the battery side of the fuse block, or ignition switch, to get proper charge voltage.

Frank,

What gauge wire do you recommend for this #2 wire to the fuse box?

.bjb

enjenjo · July 20, 2006, 01:53:29 AM

16, or 14 gauge is fine. That wire is just for a voltage signal.

PeterR · July 20, 2006, 09:21:30 AM

Quote from: "enjenjo"The number 2 terminal sets the system voltage, and by hooking it directly to the battery, it senses battery voltage, instead of the system voltage inside the car. So even though the alternator may be seeing 12.8 volts at the battery, you may only have 11.8 inside the car. So you are better off hooking that wire to the battery side of the fuse block, or ignition switch, to get proper charge voltage.

While it is certainly true the cabin system will be maintained at nominal voltage, the battery terminal voltage will necessarily be higher by an amount equal to the drop across the feed wire.

The service life of a wet cell battery is affected by the charge voltage, and voltage regulators are set to provide optimum voltage for battery longevity.

This means that taking the feedback from the cabin fuse block will inevitably reduce battery life.

A compromise is to monitor the battery voltage and run all heavy load items from relays fed from the battery post (or starter terminal). The current drawn through the feed wire to the cabin fuse block will then be reduced considerably and as a consequence so will the voltage drop, providing a more stable voltage throughout both the charge and load circuits.