Testing a Reg/Rec

pinstripe...,

The best way to test it is to eliminate it. You didn't say what year or model you bike is as there are two setups. One is '71 to '79 and the other is '80 to '83.

If an early model unplug the regulator plug of the reg /rect, run a jumper from the battery + terminal to the green wire brush.
If a late model, then run a jumper from ground to the green wire brush.

In both cases, after you have run the jumper, start the engine and check the battery voltage. If the battery voltage climbs steadily to 15 volts, then the regulator is bad. If the battery does not climb steadily to 15 volts, then the regulator is probably OK and you can look elsewhere for the problem, starting with the rotor resistance.

DO NOT ALLOW THE BATTERY VOLTAGE TO CLIMB ABOVE 15 VOLTS!

With the regulator bypassed, the voltage is...well...UNREGULATED and can climb to a very high and destructive number. The jumper is a test only...you cannot run the bike that way.

To test the rectifier part of the reg/rect, use an ohmmeter and measure between each white wire and the red wire, then reverse the test leads and measure again. One way should read a low resistance, the other should read a high resistance. The high should be at least 10 times the low resistance.

Then, do the same tests between each white wire and the black wire.
 
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The haynes manual showes how to test it with an ohm meter. just follow the chart. it has to be removed from the bike to test it.

If he has an early model bike, then the Haynes test is only valid for the stock mechanical regulator.

If he has a later model, then the Haynes regulator tests are only valid for the stock solid state regulator not the after market one that he has.

In both cases, the Haynes test is valid for the rectifier part of the reg / rect.
 
What voltage do you get when you rev it up? At idle 13.7 is ok. It should rise to 14.5 at any thing much over idle. Rev to like 3000 to 5000 rpm it should go to 14.5 but no higher.
 
Thanks pete, just to be clear,mikesxs is selling a solid state reg/rec that is from "an original supplier" so wouldn't the ohm test described in the haynes manual work even though it is an aftermarket part?
DT
 
double....,

The tests for the rect part will be the same. The tests for the rag part could be the same. If it matches the readings, it's probably OK. If it doesn't, you won't really know.
 
So if i am getting power into my reg/rec via the red wire, but i am not getting any power out of my reg/rec to my stator... Is that a good indication that it may be bad? Also I have a blueish/green wire coming from my stator, its right next to the safety relay wire, is that anything important? I was told it may be nuetral light wire, id just like to double check to make sure thats right?
 
Keep in mind that a result that would indicate a bad regrect can be caused by a bad connection to it, and I don't mean a dirty connector. On my '81 grounding the green wire worked great so I thought I had a bad regrect, but come to find out the connection to the green wire on the harness side was bad. The crimp to the wire, itself - so cleaning the connector didn't help, and grounding green on the wrong side of that connector was telling a lie.
 
Ksboy, power doesn't flow from the battery to the reg/rec on the red wire. As the alternator makes power the recifier changes the AC to DC then sends this DC to the battery on the red wire to charge the battery.
If you look close you will see a sky blue wire hooked to a switch on the top of the transmission. It goes from the switch into the stator harness just above the case. It comes up to the big plug the 3 whites, the brown and green wires go to. On the bike side of the big plug the sky blue wire goes up to the neutral light bulb.
Power after the switch goes to the neutral light bulb on a brown wire. From the bulb on the sky blue wire to the switch on the tranny. When you put the bike in neutral the switch closes and grounds the sky blue wire and makes the neutral light light up.
If you study the diagram for your year/model of bike you will see this.
Leo
 
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