NEW Voltage Regulator burning up - 2000-2001 quadmaster 500 LT-A500

[cfauvel]

2000-2001 quadmaster 500 LT-A500

ohoh....bought a a new voltage regulator from ebay and it solved a hard start problem. I have only been starting it and not riding it as it was a fixer upper for bro-in-law. Today he came down to pick it up and we went riding up and down the street to find the thing smoking so bad that it nearly caught fire.

Do you guys think it is just a cheap voltage regulator and should use the true OEm regulator OR is there is something else that could be cooking these? The original burnt up too. 

What could be causing these regs to fry?

UGH

 

[Ajmboy]

This is from overheating and either its a bad unit, incorrect, or you have other issues. Unfortunately, you'll need to get another one and then start testing voltage. Can you post a picture? 

[cfauvel]

I'll get a pic this lunch time....I had to pull the yellow wires and red wires apart because withthe insulation burnt off (and motor off) the short circuit was still draining the battery....it is SO bad.

[cfauvel]

Ok did some preliminary tests.

Continuity tests between yellow wires and ground.....all three wires show OPEN, which is what I would expect

OMH test between all three yellow wires. 

Outside to outside = starts off at .6 then drops down to .4 after a bit.

Outside to middle =  starts off at .6 then drops down to .4 after a bit.

second outside to middle = starts off at .6 then drops down to .4 after a bit.

I don't think the resistance of the stator is right....will do AC volt check at lunch.

 

[cfauvel]

Just checked the service manual and it states the ohms should be .1 - and 1.0...so I'm within specs for that,
 

maybe simply a bad NEW regulator.

 

[cfauvel]

Ok...at idle the AC voltage is as follows (the three yellow wires)

Outside to outside = 30+

outside to middle = 30+

other outside to middle = 30+

 

at some unknown RPM where the throttle is half way down (don't have a tach)

outside to outside = 70+ volts

Outside to middle = 65V

other outside to middle = 65V

I think the stator is actually ok.

 

oh and I tested the ground on the plug that had two black wires and two red wires, 

with probe on each black wire to ground, they both shown continuity..did it to the frame as well as battery ground wire.

 

Got an offer from the ebay seller to refund me the cost of the original as may have been defective...we'll see.

 

[cfauvel]

Ok guys...got the new regulator today and am a bit worried.

At idle /cold start, using a infrared therm sensor the reg jumped to 130 degrees  F in time at all.

Went down the culdesac and took reading again and it was nearing 170 degrees F...

I don't think that is good.

thoughts?

 

[davefrombc]

Doesn't sound  right to me . I wonder if there is a fault in the  stator  that  is making it  produce  much  higher  voltages  than  normal. Something is  making the regulator sink  a  lot  more  power than it's designed for.  Foolish  question , but  is the battery  installed right way  around? I  can't see   ignition  working  if  it  is  backwards,  but stranger things  happen  sometimes .

 

 

 

[Ajmboy]

On 3/14/2018 at 12:39 PM, cfauvel said:

Ok...at idle the AC voltage is as follows (the three yellow wires)

Outside to outside = 30+

outside to middle = 30+

other outside to middle = 30+

 

at some unknown RPM where the throttle is half way down (don't have a tach)

outside to outside = 70+ volts

Outside to middle = 65V

other outside to middle = 65V

I think the stator is actually ok.

 

oh and I tested the ground on the plug that had two black wires and two red wires, 

with probe on each black wire to ground, they both shown continuity..did it to the frame as well as battery ground wire.

 

Got an offer from the ebay seller to refund me the cost of the original as may have been defective...we'll see.

 

Isn't this voltage too high?

[cfauvel]

25 minutes ago, Ajmboy said:

Isn't this voltage too high?

Well I don't think so ...attached are the relevant pages from the service manual.....

the V from the stator is stated to be 60+ at 5000 rpm....and I'm getting that

I didn't do the tests for regulator/rectifier  (the grid), confused on that one really...but I'll try.

 

 

[cfauvel]

52 minutes ago, davefrombc said:

Doesn't sound  right to me . I wonder if there is a fault in the  stator  that  is making it  produce  much  higher  voltages  than  normal. Something is  making the regulator sink  a  lot  more  power than it's designed for.  Foolish  question , but  is the battery  installed right way  around? I  can't see   ignition  working  if  it  is  backwards,  but stranger things  happen  sometimes .

 

 

 

well that battery is hooked up right.

I'll price out a new stator, just in case and if cheap enough go ahead and replace it.

seems awfully coincidental that the OEM fried, the first after market fried and now the second after market is really hot.

 

 

[cfauvel]

Well I posted the question to the aftermarket seller of the part, and they replied that though the description states it IS for the ATV in question ; it is in fact NOT the right part.   So taking it off and sending it back, they'll refund me and pay for shipping...

on the hunt for a new one.

[cfauvel]

Well got a new one, from a completely different seller...the fins are bigger and the depth of the fins were more than original requiring longer bolts.

Started the motor and waited about a minute, with my thermo got about 90+ degrees.

went up and down the street at a good clip and re-took the reading and got around 100 degrees....I think I am good to go now. I'll try it several times this week before returning to my bro-in-law.

and the the other seller is refunding my money.....wow

[davefrombc]

Glad you  got it  sorted out.  I'll  have  to  remember to  get  people  to  check  the  voltage regulator  next time  I  try  to  help  someone with what  sounds for all  the world to  be  a carburetion problem  that  they  cabn't sort out .... And  to  not  assume  they   have all  the air filtration elements  installed since the  trouble   with at  least one other  system   seems to  have stemmed from them  leaving out  one filtration  element that  was  factory installed..  We all  learn  new things all  the time ..  Problem  for  us  older  ones  is remembering what  we  learned.

[cfauvel]

24 minutes ago, davefrombc said:

Glad you  got it  sorted out.  I'll  have  to  remember to  get  people  to  check  the  voltage regulator  next time  I  try  to  help  someone with what  sounds for all  the world to  be  a carburetion problem  that  they  cabn't sort out .... And  to  not  assume  they   have all  the air filtration elements  installed since the  trouble   with at  least one other  system   seems to  have stemmed from them  leaving out  one filtration  element that  was  factory installed..  We all  learn  new things all  the time ..  Problem  for  us  older  ones  is remembering what  we  learned.

And get this weirdness...

with the original OEM regulator (but burnt), had hard starting.
with the first new reg (before burnt) no hard starting

with the first reg (after burnt) no hard starting

with the first reg NOT connected, no hard starting

with second reg (not burnt) connected, no hard starting

with third reg (not burnt) connected, no hard starting

I wouldn't think a regulator would come into play with the engine running or starting, BUT as soon as I replaced the first OEM reg, bamm started fine.

I could have been seeing anecdotal/coincidental things, and just BE carburetor cleaning up itself. 

 

maybe next time have the guys simply disconnect regulator when diagnosing hard start scenario as a last ditch.