HS700UTV stator test

[Everyday Medic]

I have a 2012 HS700UTV EFI, I am from canada so it was marketed under the name power max roughrider 700. I use this machine to plow and general yard work. I have been slowly over the years working electrical bugs out.

Yesterday the SxS well my son was using it began to make a wire burning smell.  We found that the wires coming into the voltage regulator/rectifier had burnt and melted the plug. Because if this I will be replacing the voltage regultor. 

Before I replace (have to the plastic is destroyed) I wanted to test the stator to ensure that there was not an over power. Now I know this is very very doubtful as I believe wires in the harness had shorted eachother causing the melt down. But just to be sure.

I would like to know if anyone can answer, what the ohms reading should be across the windings of the stator. It is still in the bike.  

Second, there is 5 wires... 3 white they plug into the bottom or back side of the regultor.  There is one black and a red with white strip, which two terminals would these plug into on the front of the regultor? I know the center front is  it used as this is plugged on the now melted connector.

Thanks for any advice and help.

John.

[Ben1098]

Your stator is a 3 phase "Y" output.  The winding "LEGS" are the 3 white wires......call/label them A B C.  Look at a parts list to see the stator is a laminated steel ring with a multiple of 3 poles---like 12 or 15.  The windings are connected BUT NOT TIED TO GROUND at the starts----thus the schematic Y look.  Each leg is wound in series on every 3rd pole and act like stacking a string of batteries in a 5 cell flashlight....except the poles produce AC.  The AC output is measured from white to white, white to white, white to white.........A-B, B-C, and C-A.  Idle voltage is around 20 VAC leg to leg (3 times).  Higher RPM will produce on some systems around 80 VAC.....CAREFULL HERE.  The resistance check (here again leg to leg) is thru 2 sets of pole coils.....IN one of the whites----to the center tie point----OUT to the 2 other white wires.  Measure A-B, B-C, C-A......  .2 to .3 ohms.  Also check for any path to GND....high M ohm  scale should be infinite as in open circuit.  A 120V/40W light bulb will glow when connected A-B, etc.  Some systems will blow the bulb if motor Rs too high

Your problem with the melted connector plug was corrosion.  The connection resistance will heat up the terminals and with enough heat, melt the nylon connector body......this goes on for a while THEN it goes BAD when the terminals touch.....shorting out the STATOR windings.  If opened up, you will find the varnish burned off 2/3 of the 2 legs effected.  The coils short down and the resistance check will be sub .1 ohm.  Output voltage test will NOT be equal leg to leg also.  As an added bonus, the stator will cook off with additional engine run time.

I found that the voltage REG will still be good.....burned terminals and all.....most of the time......but die later.

The RED wire goes to the + battery terminal.  Black goes to GND....- BATTERY POST.  Test with a test light to ensure a good connection as in probe to REGULATOR  RED wire and clamp to GND     AND      probe to REGULATOR  BLACK wire AND CLAMP TO BATTERY + POST.  Voltmeter will lie to you and say a good connection.  An example would be BLK test lead to GND......lick finger and touch RED meter lead AND use another finger to touch the + battery terminal.....meter will read 10 to 12 VDC...says you have a good 12V....NOT.

BONUS HINT:  finding the correct connector and terminals to match the REGULATOR might be tough.  FIX is to use a aftermarket RICK's regulator that has pigtails.......cut and strip both stator and regulator wires.....match R and B......the 3 ph whites don't matter...totally random mix when harness was produced and regulator has 3 identical input circuits.

 

TEST STATOR FIRST FOR DAMAGE/FAULTS.

[Everyday Medic]

Thank you very much for the insightful and complete answer. Straight up hate the electeical on the bike. I will be replacing the stator, running .1ohms across 2 phases. Thank you. 

[Ben1098]

Be careful with meter readings.  Short the test leads together.....most meters will not show 0 ohms.  If you start out at say .3 and you have .2 in the circuit, meter will give .5 ohm.  Some meters start out NEGATIVE and then subtract from the total like  -.2 +.2  will indicate a dead short of 0 ohms.  I use a LCR bridge meter with 4 leads to measure low resistances.  The real tell is using the L inductance scale.  Leg to leg to leg value should be very close (with the following condition---------the flywheel has multiple (of 3 again) magnets glued to the inside of the "drum".  The L value will change with the location of the N-S gaps as engine is slowly rotated.  Go for the MAX value).

If the windings are shorted turns (not burned open-----shorts in the layers of wire build)------the inductance L will be lower by a factor of 10 or greater leg to leg.

Perform an at idle OUTPUT test with a 40W to 60W light bulb load.  The regulator is unplugged from stator.....the bulb is connected to the stators WHT WHT WHT leads with 3 tests.  The bulb will be dimmer when connected to a damaged winding (set/phase pairs).  Beauty of this test it is a current draw and not just an unloaded meter voltage reading.  Think of a weak battery that handles the headlights of but fails on the 200A + starter draw.    BEN

[Ben1098]

did the above REPLY on load testing the stator make it??????

[Everyday Medic]

Yes, thank you. Lucky enough for me the stator appears to be working in proper order across all tests. I have worked my way back and tested the voltage regulator as well. This was completed by attaching the 3 leg leads to the posts of the regultor, then testing the voltage  on what I know the ground and the battery lead are this let me know the which leads on the voltage regulator, for which wires

After some careful consideration I believe the issue came down to a faulty red wire, when this is measured I get 6 volts of current on a good battery. With widly swinging resistance but not to ground. I believe that the red wire has broken somewhere along the line and has caused the issue. I am going to simply bypass the red (increase the guage as well) to the battery.  However my problem is, that I need to find where the factory red leads to. I do not want to leave a possible hot wire anywhere in the system. 

Although it would be super impressive at the end of my 3km driveway mid winter blizzard to have a bonfire, the wife disagrees

So by chance do you have any idea where the red lead from the regultor goes to. If I can avoid the the mess of a wire loom I'd be beyond happy.

 

Thank you very much for all your help.

[Ben1098]

Start at the battery + post.......this node will have 3 wires----2 heavy and 1 lighter Ga.  Heavy(s) go to starter solenoid and winch contactor (assuming your unit has factory or owner installed wench).  The lighter red wire goes to the 30A MAIN fuse and then to a 4 pin connecter.  I assume your regulator is mounted under the hood also...frame rail high drivers side.....which go into the harness gathering up multiple pigtails and gets fatter as it heads to the passenger side.  Your problem is inside the loom and less than 6' of run.  The problem with the RED wire is a blind splice inside the loom with a CRIMP JOINT.....as the +12V ALWAYS HOT goes to the IGN SW also as a branch circuit.

Now to rain on your parade-------the crimp is a BAD high resistance connection------it can turn into a meltdown like the regulator connector....BUT A BURN WILL TAKE OUT OTHER WIRES IN THE HARNESS.....Razor blade......careful cuts of the loom sheath......find the node (crimp tie in or "breakout---in cable slang")....strip back the insulation for both wires....scrape/sand/brass brush the wire strands.....I like to then do a twist loop of the branch wire over the main run wire-----solder (rosin core)  60/40 LEAD still the best solder to use if you have old stock.

BUT.....lets determine that the RED wire has a problem.  Test light stabber type (I used actually 2 of them----one with the standard wimpy light bulb   AND   one with a Chevy dome light round glass tube bulb----lots of current draw and gets handle hot with use.

Connect clamp to - Battery post.  Stab the + post......light burns bright.  Next stab the MAIN fuse both sides.....should be bright.  Next go to the 4 pin connector...bright?  Now jump to the RED wire on the Regulator. Should be bright------IF NOT you lost it in the harness. 

TRICK TIME:  Called the shake test.....leave the stabber on the Regulator RED wire and then thump the harness heading back to the battery box on passenger side......light flicker means you are on top of the splice or close.  Cut the wire ties (holding the harness) and then FLEX the harness looking at the test light bulb brightness/dim/flicker.

 

BONUS TIPS

Rear diff-----VSS is the plug (unplug the connector and then screw out the sensor---don't wind up the leads).  Check the fluid level.....IF not serviced correctly most are low from factory.... monkey shops and on line buys skip this one.  No need to explain the gore here.

Air in cooling system-------you get a hot engine/cold radiator overheat condition.....means you warp head/jug/head gasket leak.  Raise the front of SxS at least a foot (12") and fill radiator neck 50/50 mix.  Puke jug hint later.  Locate the head bleed screw where you would think the thermostat would be (nope---down low by the stator/flywheel)  Should be a 8mm hex head.....this bolt is easy to twist off so don't go heavy on the Al sealing washer.  CRACK open with engine running......if air in head----bubbles then solid antifreeze.  Milk the rubber hoses low in passenger side to BURP-----watch filler neck-----will rise and fall.

RUN engine and feel the head (usually the hottest spot) or use a IR temp guy (AKA COVID-19 TESTER).  An AIR BLOCK will keep the coolant from flowing.  Follow the head coolant connection and check for the AL pipe also getting warmer....Heat should make it to the radiator also.......BURP.......warmer antifreeze will overflow.......IF GOOD...STOP.....ready to purge the puke jug......HINT....follow the hose from filler next to the jug....these hoses like to split.          FILL to COLD line plus an extra 50CC for the hose volume.  MOTOR OFF......connect the hose back to filler neck and slightly pressurize the jug......object is to fill the hose and remove air bubbles....install radiator cap while slowly "filling the neck".....RUN engine checking temp everywhere------head------Al pipes----radiator top and bottom.  Should see a few Deg temp difference thru the system.

ELECTRIC COOLING FAN.......common problems

No =12V at fan... hot but not running)-------one of 3 problems.  Temp switch failure (bottom of radiator).......connector in mud/crust with a bad connection to the 2 lugs..........harness failure of KEY ON +12V open to the thermo switch.

The thermo sensor on the head is for the dash.

Have KEY ON, test light clip to GND and stab the radiator thermo switch lugs.....one will light (red tracer?) coolant cool....both will light with radiator HOT......Fan should run.  TO TEST the circuit for T/S for fault.....a HEAVY paper clip opened up to make a horseshoe shaped jumper wire......KEY ON----jump switch.....fan should run.  This means that if the radiator gets hot enough to toggle the thermo switch, the fan will work.

[Everyday Medic]

Thank you for all the tips. I will be tracking back ye ol Red today.

Thanks for the bonus tips. The battery is no longer factory, it a a dual deep cycle battery set up with automatic isolator.   Because I plow I put a huge demand on the batteries with the winch, the lights (low draw led light bar). I have also installed a hydraulic pump for my custom hydraulic blade turn.  Because I put alot of demand on the machine and being an ex helicopter pilot I religiously change the dif fluid beginning and end of ever plow season, I know more then needed but it is small amount and a little peace of mind. 

I did run into the cooling fan issue, actually replaced the temp sensor a few times over the years until that no longer  worked. I then  dug deep into the system and in the absolute most awkward place I found a diode in the circuit, after testing that diode and finding it had failed, I replaced with a high quality one,that was the issue when changing the temp sensor out did not work. Now 2 years no issue. 

The coolant has been completely changed in the machine, me and my preventive maintenance. Also installed a small heater core/fan heater in the cab, so that required a change of coolant. Winter gets damn cold here, and plowing always seems to happen at night in the worst winds and snow storms. Yuppers have a cab cover. 

I appreciate every bit of insight you have provided. 

[Everyday Medic]

I wanted to thank you for all your help. I tracked back the red and found the splice, all was good there. I did replace the red wires from the ignition and voltage regulator to the 30 amp fuse. I did not in line splice just ran two wires to the fuse connection, and put them togeather in the connector.  The Voltage regulator still works this far. I used connectors to attach the new wires then used silicon to seal and prevent arching. 

Once again thank you.