Alternator Not Charging

replace the three wire Motorola alternator question
I connected the three wires of the external regulator to the alternator correctly
what is the grey 18 gauge wire to the dash cluster do? It connects to the idiot light, IS THIS THE EXCITER CIRCIUT? It GETS power from the gauge cluster? Can't I take power from the big lug on the rear of the alternator WITHOUT the light connected at the cluster? I think that that is the correct question

Question how do I bench test the external regulator? What leads for the tool go where, on what settings?

Bummer, no answers yet, several readers, thanks

Photos of oem Motorola three wire rear faces of alternators and Ford Prestolite 4 wire systems from Intermediates please

 

Is not a three wire alternator internally regulated?

 

The Motorola Alt used a solid state external regulator on some models. To test the reg you needed to connect it to a alternator and run it up on a test bench that had a volt and amp meter.

 

The gray wire, as you mentioned, to the dash is the exciter circuit. As Howard stated make sure the light bulb isn't burned out. Make sure the light isn't an LED Bulb . LED doesn't draw enough to "excite" the alternator, when this happens the alternator will not charge. Learned this from experience.

No, and No. When the ignition key is turned on, the dash "Idiot" light draws power to "Excite" the alternator so that once the engine is running the alternator starts producing electricity. If the alternator doesn't get excited it won't produce electricity.

Can you post pictures of the back of the alternator and the regulator in your set-up?

 

In theory yes but your only testing one function of the regulator.

 

NO Sir, Motorola system OEM for 1966 is externally regulated and had tappets and springs not solid state electronics

 

OK now I need to write more here,
right now there is no grey wire installed, it burned up the wire loom fire,
there is no light bulb installed in the cluster,
there is no power connected to the cluster, I never had a fuel gauge in the tank, its a blank, or monitor temperature. I only use the speedometer
IF I convert to the one wire 12 si alternator, am I done there?
If I change to the 12 si, does the direction of the rotation matter, the alternator cooling fins look backwards for the 12 si from the Motorola fins behind the drive belt pulley
thanks for replying Dale

 

no

 

12 si it is, thanks everyone

 

While one wire alternators are popular due to ease of installation, they have a few drawbacks as well. The one wire does not have accurate (if any) voltage sensing, must be self energized by revving the engine at start up, and regulators are not easily found, like 3 wire regulators. This last issue is somewhat lessened by the fact that fewer and fewer parts stores are selling rebuild parts for any alternators. Google "mechanical man" , "Ron Francis" or "12 volt man" for further info. Good luck!

 

I did a one wire swap and it’s just wise. Remember it takes really low rpm to start charging with a one wire. If your engine is idling at 900 that alternator pulley is flying. Just run heavy gauge wires and ground. I grounded the battery direct to a starter bolt. Then ran a ground from alternator mount to frame and frame to body. This gives you solid grounds all around and fast cranking along with sufficient charging.

 

A '66 should not have an ammeter, but it should have an "Amps" light. If you install a one-wire Delco alternator, I would (1) remove an any aftermarket ammeter if present, (2) install an aftermarket voltmeter, (3) protect the Jeep from fire with fusible links between the ammeter and battery (in that "1-wire"), and between the battery and the dash. The one-wire is going to make way more amps at full charge than the original Motorola, and sending all that power to the dash and back through a potentially dodgy ammeter risks a carbeque. With a 1-wire Delco, you have no amps light capability, so you need something to tell you the conditon of the charging system - hence voltmeter.

 

A one wire alternator may be the simplest to install, but in my opinion it is not the wises. It is worth the effort to install a three wire alternator which when installed correctly, monitors the electrical systems load and responds accordingly.

 

Yes this is a good point, however the delta is minimal between the 1 and 3. Running the sense wire to a further load draw on the 3 wire versus installing the charge wire at the solenoid isn't going to make a huge difference on a small Jeep. If you have lots of electrical load that also switches on and off (like seat heaters, window defrosters) then the 3 wire is a notable improvement. But on our Jeeps all we run is a basic ignition system and lights. Some have a winch which draws so much any alternator will know to start charging. I think the wisest install on our little Jeeps come down to what you feel like wiring up because they'll all do the job with ease.

 

OK Tim I'll bite on the Voltmeter idea.... From the Battery with a fuseable link wire on Say 10 Gauge stranded wire TO the Voltmeter... From the Voltmeter mounted in the dash (back to the Battery? with a fuseable link and a 10 gauge wire?

 

Yea never figured out the photo thing. The system WAS oem Motorola from 66

 

The fusible links protect the Jeep from the battery (fire!) in case of a catastrophic short in the wiring or alternator.