# Where is the regulator / rectifier on my Briggs / Craftsman?



## skarweb (6 mo ago)

Briggs & Stratton 31R907/0062-G1
Craftsman T 110 (CMXGRAM1130036) (13AN77XS093)
The battery drains while off. I tested this by multimeter between the negative terminal and the disconnected wire registering voltage.
The battery is good.
With the engine on, the multimeter registered 50+ Volts coming from what I think must be the alternator wire.
But I cannot find the regulator or rectifier to test it. Nor can I find one for this model anywhere. But there must be something to convert AC to DC.


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## FredM (Nov 18, 2015)

If you have a 2 wire like photo, then there will be a diode in the red positive wire, it would pay you to check the wire with a multimeter both ways with the multimeter set to ohms, disconnect the battery when you check, otherwise you will most likely damage your multimeter, the diode could be open or most likely shorted and the battery is getting AC power, hence the large charge you have tested at the battery.

You could set the multimeter to DC volts and just disconnect the connection and place a red probe onto the red wire pin in the plug on the battery side of the connection and the black probe to earth and if you get a 12 volt reading then the diode is shot, the reading should be zero,

The fact that the battery is draining suggests the diode has shorted and is allowing battery power to cycle back into the stator windings and causing the draw down.


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## Bob Driver (Nov 1, 2017)

FredM said:


> If you have a 2 wire like photo, then there will be a diode in the red positive wire, it would pay you to check the wire with a multimeter both ways with the multimeter set to ohms, disconnect the battery when you check, otherwise you will most likely damage your multimeter, the diode could be open or most likely shorted and the battery is getting AC power, hence the large charge you have tested at the battery.
> 
> You could set the multimeter to DC volts and just disconnect the connection and place a red probe onto the red wire pin in the plug on the battery side of the connection and the black probe to earth and if you get a 12 volt reading then the diode is shot, the reading should be zero,
> 
> ...


That's the confusing thing about the Briggs 31000 Series, they came with three different alternators set ups depending on age.... Only the Dual Circuit has the diode in the wiring harness... They all use different rectifiers/regulators and they are easy to ID by the connection
Briggs Alternator ID Link

Dual Circuit --- Briggs # 696459 since 2007
Tri-Cricuit --- Briggs #696457 up to 1988
Quad Circuit --- Briggs #696458 since 1984

*696459 Dual Circuit with Diode*









*790292 Dual Circuit Regulator*









*696457 Tri-Circuit*








*794360 Tri-Circuit Regulator*











*696458 Quad Circuit -* This is the most common charging unit Briggs uses today










*691185 Quad Circuit Regulator*


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## FredM (Nov 18, 2015)

skarweb said:


> Briggs & Stratton 31R907/0062-G1
> Craftsman T 110 (CMXGRAM1130036) (13AN77XS093)
> The battery drains while off. I tested this by multimeter between the negative terminal and the disconnected wire registering voltage.
> The battery is good.
> ...


You now have the choice to determine which type regulator is on your mower, the diode is inline and the encapsulated box type mostly sit under the blower housing connected to the charging wires from the stator, but from your comments, you will most likely have the single diode type.


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## FredM (Nov 18, 2015)

Bob Driver said:


> Dual Circuit --- Briggs # 696459 since 2007
> Tri-Cricuit --- Briggs #696457 up to 1988
> Quad Circuit --- Briggs #696458 since 1984


Bob!!, would briggs confuse the running numbers for the year concerned as in your post??.

I do have an alternator chart from Briggs, but it is like me goes back to the 80's and ancient.


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## Bob Driver (Nov 1, 2017)

FredM said:


> Bob!!, would briggs confuse the running numbers for the year concerned as in your post??.
> 
> I do have an alternator chart from Briggs, but it is like me goes back to the 80's and ancient.


What Briggs has information out on-line that is inaccurate??? Come across it every day!!!!! Just went through it rebuilding a Tuff Torq transaxle. Only thing I had to work off was a parts diagram..... Tuff Torq website had the left side parts diagram posted under the right side transaxle part #. The swash plate mounts one for the left side and the opposite for the right side. If you might them both the same way, left side rotates forward, right side rotates backwards. Had to drop the right side back out of the mower and flip the swash plate.... I mumbled some really bad things about Tuff Torq that day


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## FredM (Nov 18, 2015)

Bob Driver said:


> I mumbled some really bad things about Tuff Torq that day


 And as you get older, you get worse, believe me, specially when the finger tips have smoothed off and you have trouble trying to pick up small nuts and screws.


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## skarweb (6 mo ago)

FredM said:


> You could set the multimeter to DC volts and just disconnect the connection and place a red probe onto the red wire pin in the plug on the battery side of the connection and the black probe to earth and if you get a 12 volt reading then the diode is shot, the reading should be zero,


Thank you. College level physics was a long time ago and never this practical. But thank you so much for pointing out the diode to me. It is registering a small voltage when off and battery disconnected (when stuck in the literal ground, but not up against a bolt).
BTW, with the engine on and multimeter set to AC volts, it was registering 53+. I'm just baffled at where the battery is draining with the mower off. With the mower on, it charges the battery just fine (I'm pretty sure).


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## FredM (Nov 18, 2015)

skarweb said:


> Thank you. College level physics was a long time ago and never this practical. But thank you so much for pointing out the diode to me. It is registering a small voltage when off and battery disconnected (when stuck in the literal ground, but not up against a bolt).
> BTW, with the engine on and multimeter set to AC volts, it was registering 53+. I'm just baffled at where the battery is draining with the mower off. With the mower on, it charges the battery just fine (I'm pretty sure).
> View attachment 80783


With engine running and you are doing a battery test, place the red and black probes on the correct battery terminal, the meter should be set to DC volts not AC, the output reading should be between 13.5V and 14.5V, the diode(called a half wave rectifier) if working correctly stops the AC pulse and converts to DC to charge the battery, the black wire in the connection runs AC to power the headlights if fitted.

You also wont get a true reading with the black meter probe stuck in the ground(earth) like in your photo, you have rubber tyres which are an insulation barrier, you have to make the circuit with an engine ground, if the probe cable is long enough, then earth it out on the battery negative post, or even on the engine case behind your meter in the photo, the case is clean enough for a ground, and see what reading you get.

If you believe the diode is ok, then as a test, disconnect the positive battery cable from the post and let the mower sit for a week or two and then check the battery, if the battery is ok as you say, then it will still have charge, now connect the battery cable and let sit again and tell me what you have battery wise.


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## skarweb (6 mo ago)

FredM said:


> With engine running and you are doing a battery test, place the red and black probes on the correct battery terminal, the meter should be set to DC volts not AC, the output reading should be between 13.5V and 14.5V.
> 
> If you believe the diode is ok, then as a test, disconnect the positive battery cable from the post and let the mower sit for a week or two and then check the battery, if the battery is ok as you say, then it will still have charge, now connect the battery cable and let sit again and tell me what you have battery wise.


With the engine on, the battery takes awhile to charge to up over to over 16V. With the engine off, it was 12.85. I'm letting it sit with the positive cable off, though we're going to need to use it soon.

I'm still baffled at how to test the diode. I tried sticking the positive multimeter lead through the insulation above the diode and the negative below. But I get 0V. And with leads reversed, I get 0V (when it shouldn't register). I do not know if I'm not touching the wire, or if there's another way to test it. Thanks.


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## FredM (Nov 18, 2015)

To check the diode for open do as you did in your photo, place the red probe into the 2 wire connector against the red wire pin and the black probe against the engine case, drag the probe point against the engine case to get a good ground, set the meter to 20V DC, if the diode is ok, then there will not be a reading, leave the battery connected for this test.

If you get a voltage reading testing this way, then the diode is leaking.

You can use the OHM setting on the meter to test also, but you would have to disconnect the battery, I can explain that if you want, the first test is simpler and will tell you what you need to know.


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