1976 cj360T not charging

zimmy · Posted: Mon Apr 11, 2011 7:42 pm Post subject: 1976 cj360T not charging

Hi all:

I'm working on a '76 cj360T that is not charging. It runs well when the battery is charged but then dies as it is ridden. It doesn't seem to make the headlight brighter when it is rev'd. I'm assuming the rotor or stator is trash. Don't know which one. Considering buying a rotor and stator assembly on Ebay. Has anyone changed these out? I've got a rotor puller for my cb750, but not sure if the crankshaft has a threaded end on this 360 that will work with my puller. Does anyone have any words of wisdom? This 360 has no starter motor so I don't need the starter gear. I wonder if I can buy a whole assembly off ebay and remove the starter gear?

I'd appreciate any advice.

Thanks,

Jim

MR.CHocko · Posted: Mon Apr 11, 2011 10:39 pm Post subject:

Before you start buying parts I would also suggest you check out your rectifer. Yes you can buy a used on ebay very cheap. But first unless you do some tests to figure out if it is rectifer or the stator you will be just replacing parts instead of fixing the problem.

KirkN · Posted: Tue Apr 12, 2011 4:21 am Post subject:

a big +1

Don't go replacing parts without doing the simplest of tests first. If you don't have one, pick up a cheapie multimeter at any cheapie auto parts store for ~$10.

My favorite technique is to hook the meter to the battery and tape the meter to the tank (on a small towel or rag) and go for a ride. You can watch and confirm the voltage drop as you ride at different speeds and RPMs.

Disconnect the regulator from the black wire and the yellow wire. This will take it out of the circuit, and won't do any harm for a short ride or test run. If the voltage stays up, that was it. Of course, you don't really need to go for a ride, just run the motor with bike parked. (Maybe keep a fan on it so it doesn't overheat).

Disconnect the rectifier from the multi-plug and measure the 4 diodes in each direction - two inputs are pink and yellow; two outputs are green and red or red w-white stripe?. Measure pink to green, pink to red, green to pink, red to pink, then check for yellow to red, yellow to green, green to yellow and red to yellow. All four diodes must conduct in one direction only and not the other. That's why you check each color-pair in each direction. If the rectifier doesn't test out, there you go.

In the headlight bucket, in the rat's nest, fish out the yellow wire and jumper it to the yellow-white wire. This bypasses the function in the headlight on/off switch that connects the yellow to the yellow-white, which connects the two alternator outputs for additional "lights on" charging. This just confirms there's not a problem in the switch.

Finally, disconnect the alternator output plug, and with motor running, check for AC voltage on the pink-to-yellow terminals and on the pink-to-white terminals. You should see an AC voltage reading at idle which increases up to as high as 50 ~ 80 volts AC as the engine revs. If you don't, then it's likely the stator windings have failed. The rotor is just a permanent magnet and there's nothing really to fail about that.

If you suspect the stator windings are bad, you can measure resistance from the pink wire to a good engine ground and white-to-ground and yellow-to-ground. There must be no continuity to ground.

These checks take longer to write up / read than they do to actually do, and when you're done, you'll know where the problem is rather than just spending $$$.

And I should have mentioned this first - make sure that all connections between alternator to rectifier and rectifier to battery are perfect. 35-year-old connections are a large contributor to poor charging system performance.

Good luck with it, and be sure to post back your findings!

Kirk

And, not to direct you away from this site, but here's a link over to the HondaTwins site and a sticky there about 360 charging system troubleshooting: http://www.hondatwins.net/forum/viewtopic.php?f=46&t=3134

MR.CHocko · Posted: Tue Apr 12, 2011 1:30 pm Post subject:

You do not need to go for a ride to see if your battery is charging. That is just another excuse to go for a ride, and trust me I do not blame him. Just have the bike at idle, with the lights on and then with the lights off. Check the readings.

KirkN · Posted: Tue Apr 12, 2011 1:55 pm Post subject:

zimmy · Posted: Sun Apr 17, 2011 8:19 pm Post subject: cj360T charging issue

Thanks for all the helpful info. It ended up being the Regulator. It had a copper tab broken off. I ordered a cheap used replacement off ebay. We'll see if it is any good.

Again.....thanks for all the comments....this site is great!