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Not charging????

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Hey folks,a couple of ??.Bike quit charging the other day[s model].Using the service man. to run test and have a couple question.My diode test of the rect. failed but testing the gen. I have good continuity on all three legs but show cont. to grnd[1.3ohms].I thought it should be infinite.Charges a/c volts to spec..This has been gradually getting worse[sometimes works]but now not at all.Beleive the rect. is bad but the coil thing kinda thru me off.Any help appreciated. :thumbsup: Scott G.

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That was fast ,kinda what I was thinkin.Moose offers a decent upgrade and i'll replace the rect..REALLY apreciate it bud,got some big rides coming up

Scott G. .

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If any of the stator coils are shorted to ground, the stator AC voltage out-put may still test OK open circuit. But when you plug it into the RR it will not work because you now have a common ground for both the AC in-put and the DC out-put. As Eddie said, any continuity between any of the yellow wires and ground is a bad stator. Why do you think the RR is bad too? Are you testing with a meter with diode test scale? Or using a continuity light bulb?

Here is the full procedure:

The electrical system is composed of 5 main components:

1. AC generator (the stator and magnets in the flywheel)

2. The rectifier

3. The regulator (the rectifier and regulator are combined in 1 box but function independently)

4. The battery

5. And the wires that connect everything.

First things first - check the charge voltage at the battery. Battery needs to be fully charged. Running 3000 rpm you are looking for 14 volts or higher. If voltage is low, start troubleshooting the system

Stator and wires. The stator is easy to check and the source of all power so check that to verify it is good. Check short to ground, coil resistance and running AC voltage of all 3 phases as described.

It is very important to check all wires and system ground wires. You have to be systematic and comprehensive. There are no secrets or short cuts

Check the 2 pin plug from the RR. From the battery, trace the small red wire and the small black wire to the first connector. Check those 2 connections. They must be perfect. Check and replace the fuse. Look closely at the fuse holder. The fuse must be a tight fit. Check the 3 pin connection between the stator coils and the RR. Any heat tint or melting of wires or connector plastic here or anywhere else is a problem.


1) Check all connections in and out of the regulator/rectifier (RR) 3 yellow wires and 1 each black (black has a white trace) and red. Trace the red to the battery and check all connections, the fuse and fuse holder and battery terminals. Now do the same with the black wire. You are looking for any signs of heating, loose or dirty or corroded connections. Fix if you find any. Test connections with your hands to feel for any heat (under load). Hot connections are bad.

2) Use a volt meter at the battery. This test needs to be done with a good and fully charged battery. Motor off key off - you should have 12.8 or more volts. Key on, lights on, motor off - around 12 volts is good. Motor running at idle - above 13 volts is good. High idle to around 3000 rpm - 14 to 14.5 volts is what you want to see. Suzuki says 13.5 is OK but that will not keep a battery charged. Many DRZ's will show the highest voltage at idle and the voltage drops as the rpm goes up. That is ok if it is above 14 volts. It is not really dropping but your test meter thinks so.

3) Low voltage - start by checking the stator coils. Unplug the 3 yellow wires from the RR. Motor off: check each yellow to ground. (The wires from the stator coils not the RR. We will check that later) No continuity is good, any continuity is bad. Now check wire to wire: Y1 to Y2, Y2 to Y3, and Y3 to Y1. You should see about .5 ohm resistance. Any open is bad, any continuity is good. Now start the motor and check the AC voltage output: Y1 to Y2, Y2 to Y3, Y3 to Y1. You are looking for about 60 volts AC at approx 3000 rpm. Exact output is not critical but should be about the same for all 3 readings and above 50 volts. Voltage varies with RPM. Make sure you use the AC scale.

4) RR testing - remove the RR from the bike. You can test the internal rectifier diodes. Put your digital meter on diode check and follow the meter test instructions. Check red wire to yellows wires then reverse the test leads. You will get no continuity one way and about .5 volt drop fwd continuity the other. Now repeat the test black wire to yellows. You should get the opposite results for no continuity and fwd continuity with a .5 volt drop. If you are not using a digital meter with diode test function, use a 12 volt battery and a low wattage bulb and test for continuity vs no continuity. There is no good way to test the regulator except by elimination of all other problems

More info, some redundant

Look at all the wires and connections between the RR and the battery. Both pos and neg. Look at the fuse and the fuse holder. Try a new fuse (fuses can go bad without going open) If you don't find anything, make a test connection so you can test voltage at the red and black wires right at the RR. You are going to have to improvise so you don't poke holes in the insulation which is always bad to do.

At this point, I always recommend to rewire the RR output direct to the battery. Use 14 gage marine grade wire and ring terminals. Cut the wires about 4" from the RR. (insulate the cut red wire to the wire harness) Extend the RR Red and Black wires direct to the battery terminals. Even if all the connections are good, this mod will give about .5 more volts to the battery.

You should be very comprehensive with checking all the wires and terminals and connectors. Suzuki uses small wires and small connectors and any sign of heating will cause problems. Ground wires are too often overlooked but are just as important as the pos feed wires. Something as simple as the small black wire from the battery to the harness can stop everything. That is the only place the loads (other than the starter) are grounded.

There is 1 more thing to check. That is current leakage. With every thing off, disconnect the battery neg. Connect a light between the battery and the cable. Should get nothing. If the light glows you have a big current leagage problem. If no glow, continue. Use the 10 amp scale and connect between the bat an the cable. If less than 1 amp go to the milliamp scale. You are looking for less than 1mA currrent leakage.

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