1985 GL1200 Rectifier Testing

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Rednaxs60

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I have done two other threads on the electrical system for my '85 LTD and how I have come to understand the system.

https://www.classicgoldwings.com/forum/v ... 12&t=12677
https://www.classicgoldwings.com/forum/v ... 12&t=12703

I did the test on the OEM regulator from my '85 LTD. For the LTD regulator there should be three yellow wires (from alternator), two red/white wires (go to starter solenoid with a junction in the wiring harness where these wires are joined/bonded to the red wire from the starter solenoid to the ignition switch) , two green wires (ground) and one black wire (12 VDC excitation).

The two ground wires are connected to a single ground wire just after the green wires enter the wiring harness as do the two red/white wires. You will notice only a single red/white wire at the starter solenoid.

I have read the Clymer and OEM service manuals to ensure both are the same.

From the OEM:

Normal direction: Continuity (5 to 40 Ohms)

+ Probe to Yellow (3 wires - done individually) : - Probe to green
+ Probe to Red/White : - Probe to Yellow (3 wires - done individually)

Reverse Direction: No Continuity (over 6,000 Ohms)

+ Probe to Green : - Probe to Yellow (3 wires - done individually)
+ Probe to Yellow (3 wires - done individually) : - Probe to Red/White

From the Clymer:

The Clymer manual test is:

Connect the positive probe to the yellow lead, negative probe to green lead - should be continuity, reverse leads no continuity

Connect positive probe to red/white lead, negative probe to yellow lead - should be continuity. Reverse leads, no continuity.

This is the same as the OEM manual.

The Clymer service manual also has a note that can be misleading. It mentions that this test as specified is for a positive grounded meter. If a negative grounded meter is used the results will the opposite. There is no note like this in the OEM service manual.

It is possible that in reading this note, and that we use negative grounded meters, a person could switch the positive/negative leads, get opposite results and come to the conclusion that the regulator is defective. I submit that if a person uses the Clymer service manual as a guide for testing the regulator, disregard this note.

I have also found a YouTube video on how to check the rectifier diodes: https://www.youtube.com/watch?v=9LwDPHvzH90

It is a UK video and mentions connecting the positive lead of the meter to the black wire, this is our green (ground) wire, and the negative to the yellow wires. I used my digital meter as it has a diode function. The diodes were very close in readings: 491/483/491. Give or take accuracy, regulator good to go.

I used digital and analogue meters:
Digital - Analogue Meters.jpg
I used the analogue to test the regulator because I could not get a reading from the digital meter. I had read about this a few years back. I used the digital meter to check the rectifier diodes as this meter has a diode function.

the regulator I tested was Shindengen SH574A-12 that I took off my bike when I did the external alternator mod:
20171130_185755.jpg
This regulator wiring is; OEM regulator wiring - 3 yellow/2 red-white/2 green/1 black. The two red/white wires are joined in the wiring harness into a single wire, as are the two green wires.:
1985 LTD Regulator Wiring.jpg


The jumper wires I used were red for positive and yellow for negative:
Jumper Colours.jpg

The first test was for continuity of yellow leads (+) to green leads (-):
Yellow - Green Continuity Testing.jpg
The reading was 45 Ohms on the 10X scale for all three yellow wires. Reversed the positive/negative leads - no continuity.
The second test was for continuity between red/white leads (+) to yellow leads (-):
Yellow - Red Yellow Continuity Testing.jpg
The reading was 45 Ohms on the 10X scale for all three yellow wires. Reverse the leads no continuity.

The diode test was done:
Diode Testing.jpg
The readings were 491/483/491. This is the YouTube video regarding this test: https://www.youtube.com/watch?v=9LwDPHvzH90 It is a UK video, and the positive lead to the black wire is a UK ground wire colour. Put the positive lead to the green ground wire of the regulator and the negative to each yellow wire.

Hope this thread is found to be useful.

Cheers
 
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