motorolla to gm 3 wire

Timgr,,,,,,the 3 spare GM diode trios I had all very in resistance by ALOT ! but all check fine with the ohm meter. I tried all 3 , but they did not match the rest of the unit,did that matter?

 

Diodes vary a great deal from one manuf to another. For the diode trio, you dont really care what the resistance is. What you are looking for is a front to back ratio of 10:1. You have to use the diode tester to see this. Most V-O-M testers have the diode test capability. Read the resistance one direction then swap the leads and read again. Example would be =one direction reads 20 ohms the other direction should read at least 200.

 

The diode trio is different from the rectifier bridge.

I doubt the problem is in the diode trio, since that's used to make a reference voltage for the regulator. If the diode trio is bad, I'd expect it to make the alternator run at too high a charging voltage.

The rectifier bridge diodes are in an aluminum block with heat sink fins. The diode trio goes on top of the rectifier bridge.

 

Example would be =one direction reads 20 ohms the other direction should read at least 200.
yeh -I ran into that .

I did switch out the bridge too for a un-rebuilt/un -painted one but it did not seem to make a difference. anyway it is all fixed now,, just was trying to figure out where it went wrong,and why I could not find the problem inside. thanks guys for the help.

 

You guy's are making my head HURT. I haven't thought about this in 20 years,use to be right on the tip of my tounge, < damn I'am getting OLD

 

My old Willys Jeep CJ5 was converted to alternator by some unknown (to me) previous owner. A one-wire Delco SI-10. Starts charging at about 1600 rpm and charges at idle, which I have set a 1k. Runs Hi-Lo beams and tail/stop/turn lights just fine, although I am getting ready to install relays in the headlight circuits to run the headlights directly off of the battery, instead of through the wiring harness, and ALL of those connections between the battery and lights.