Lightning strike 1993 EZGO 36-Volt XT 500 Workhorse

[JohnnieB]

Originally Posted by cowboysclassics

Scratch my last post JB.

I don't have a clue whats going on but I redid the test again putting the positive DVM test lead on the M- terminal and the negative DVM lead on the B- terminal and the reading when the pedal pushed until the solenoid clicks is still full battery pack charge but as I press down on the pedal it only goes as low as 28.4 volts and no lower.

I did the test again after reading ScottyB.s post in a different thread that said which DVM lead to put on which terminal. I assumed it made no difference before since you never mentioned it. What do I try next? Thanks again.

The negative lead typically goes to the the main negative terminal on the battery pack. The B- terminal on the controller is connected to the main negative terminal by a high current cable, so it is electrically the same point.

If you reverse the leads, the voltage you read will have a negative sign instead of a positive sign.

For consistency and clarity, the negative test lead should be connected to the most negative of the two points being measured between.

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If the voltage between B- and M- is decreasing as the pedal is pushed, the controller is working. (Maybe not working right, but working.)
If the voltage is decreasing and the motor is not turning, something ought to be getting hot.

I suspect you have bad some bad/dirty contacts in the F/R switch or some bad high current cables.

Anything getting hot is a problem that needs to be fixed.

[cowboysclassics]

Originally Posted by JohnnieB

The negative lead typically goes to the the main negative terminal on the battery pack. The B- terminal on the controller is connected to the main negative terminal by a high current cable, so it is electrically the same point.

If you reverse the leads, the voltage you read will have a negative sign instead of a positive sign.

For consistency and clarity, the negative test lead should be connected to the most negative of the two points being measured between.

-----------
If the voltage between B- and M- is decreasing as the pedal is pushed, the controller is working. (Maybe not working right, but working.)
If the voltage is decreasing and the motor is not turning, something ought to be getting hot.

I suspect you have bad some bad/dirty contacts in the F/R switch or some bad high current cables.

Anything getting hot is a problem that needs to be fixed.

Thanks again JB. I have cleaned and checked all of the cables/connections and looked for any place that might be weak in any of the wires and cables and found nothing that looks to be any kind of problem.

Everything has always worked exactly as it should, and no wires, cables or components have ever got hot until I tried to do theses tests (and that could have been from me doing them so many times in a row to get as accurate readings as I can). I still think its lightning related with one or more components maybe being fried, but I am not that sharp on DC electrical stuff.

I am at a loss of what to do now other then throwing money at it and start replacing expensive items including all of the high current cables, controller ECT.

I cant really afford it right now with all the other expenses I have from all the other lightning damage to the house and electronics, but I use this cart around the farm several hours a day, and have been without it for going on 2 weeks now. Any suggestions on what to start replacing first?

[JohnnieB]

The solenoid is clicking, you get full battery voltage between B- and M- when solenoid clicks, and the motor ran when you applied a low voltage to it.

That leaves the controller, which is the only electronic device in the drive system and the most susceptible to lightening damage.

The voltage between B- and M- did drop some when you pushed the pedal, but a high impedance DVM will read voltage through a high resistance, so the MOSFETs in the controller might be bad and what we are reading is the voltage from the driver stage telling the MOSFETs to turn on.

If you are satisfied with the carts torque and speed, you probably want to stick with a stock controller.
FSIP has some Re-manufactured ones at reasonable prices, give them a call and tell them what you are looking for.
http://www.fsip.biz/RemanGolf.html

[simple man]

Just a thought, jack up the rear of the cart ( it should be already ) and make sure both rear wheels turn freely. Now block 1 wheel and try to turn the other. It will be stiff, but should turn. What you are doing in blocking 1 wheel is turning the differential and the motor. This is just a test to make sure the motor turns. If your controller tests Ok and all the high current cables were Ok, the motor may be frozen. Not likely, but I have seen lightning arc through the brushes on motors leaving the brushes " welded " to the commutator.

EDIT: Sorry, I missed the post where you said you tested the motor! Still wouldn't hurt to make sure it turns freely now.

[cowboysclassics]

Originally Posted by JohnnieB

The solenoid is clicking, you get full battery voltage between B- and M- when solenoid clicks, and the motor ran when you applied a low voltage to it.

That leaves the controller, which is the only electronic device in the drive system and the most susceptible to lightening damage.

The voltage between B- and M- did drop some when you pushed the pedal, but a high impedance DVM will read voltage through a high resistance, so the MOSFETs in the controller might be bad and what we are reading is the voltage from the driver stage telling the MOSFETs to turn on.

If you are satisfied with the carts torque and speed, you probably want to stick with a stock controller.
FSIP has some Re-manufactured ones at reasonable prices, give them a call and tell them what you are looking for.
http://www.fsip.biz/RemanGolf.html

Thanks again JB, that's kind of what I was thinking. Thanks for the link too, always nice to have some different options.

I had checked on Ebay and found some that were rebuilt for less than $200.00, but they show an additional $330.00 core charge if mine is not rebuildable. For that kind of money I am thinking about going with an upgrade from ScottyB ,even though I have no plans to ever increase the voltage from 36volts I would like to get all I can out of what I have.

I also noticed a gray wire loom that's looped above the controller that is not hooked up that comes out of the bottom of the POT box (I think that's the name). Its been that way since I got it but I have no idea of its purpose. Here are a few pics any idea of why its there.

FYI, the shiny spots on the solenoid are from a penetrant I used on the bolts to remove the resistor for testing.

[cowboysclassics]

Originally Posted by simple man

Just a thought, jack up the rear of the cart ( it should be already ) and make sure both rear wheels turn freely. Now block 1 wheel and try to turn the other. It will be stiff, but should turn. What you are doing in blocking 1 wheel is turning the differential and the motor. This is just a test to make sure the motor turns. If your controller tests Ok and all the high current cables were Ok, the motor may be frozen. Not likely, but I have seen lightning arc through the brushes on motors leaving the brushes " welded " to the commutator.

EDIT: Sorry, I missed the post where you said you tested the motor! Still wouldn't hurt to make sure it turns freely now.

Thanks simple man, that's why I started with the motor and rear end first, I thought that might be exactly what had happened. But yes it turns freely when I tested the motor.

[JohnnieB]

Originally Posted by cowboysclassics

Thanks again JB, that's kind of what I was thinking. Thanks for the link too, always nice to have some different options.

I had checked on Ebay and found some that were rebuilt for less than $200.00, but they show an additional $330.00 core charge if mine is not rebuildable. For that kind of money I am thinking about going with an upgrade from ScottyB ,even though I have no plans to ever increase the voltage from 36volts I would like to get all I can out of what I have.

I also noticed a gray wire loom that's looped above the controller that is not hooked up that comes out of the bottom of the POT box (I think that's the name). Its been that way since I got it but I have no idea of its purpose. Here are a few pics any idea of why its there.

FYI, the shiny spots on the solenoid are from a penetrant I used on the bolts to remove the resistor for testing.

Give Scottyb a call. He will come up with the right controller and solenoid for your needs, whether he sells them or not.

The gray wire loom is for half-speed reverse. Originally went from controller to the double microswitch on the F/R switch assembly, then back to the Pot-Box.
Basically, what happens is that in Reverse, a fixed 5K resittor is placed in parallel with the 0-5K throttle potentiometer, with gives you a 0-2.5K throttle instead of a 0-5K throttle. So the controller will see a maximum of 1/2 throttle while in reverse.

My guess is the somebody replaced the F/R assembly and the new one didn't have a double microswitch.

[cowboysclassics]

Originally Posted by JohnnieB

Give Scottyb a call. He will come up with the right controller and solenoid for your needs, whether he sells them or not.

The gray wire loom is for half-speed reverse. Originally went from controller to the double microswitch on the F/R switch assembly, then back to the Pot-Box.
Basically, what happens is that in Reverse, a fixed 5K resittor is placed in parallel with the 0-5K throttle potentiometer, with gives you a 0-2.5K throttle instead of a 0-5K throttle. So the controller will see a maximum of 1/2 throttle while in reverse.

My guess is the somebody replaced the F/R assembly and the new one didn't have a double microswitch.

Thanks for clearing that up JB, and all of your help. I will update this thread when I decide which way to go and the outcome.

[cowboysclassics]

I looked under the cart at the tags on the controller and the motor to try to come up with some numbers and although the tags are on both there are no numbers at all on the chrome looking stickers.

From my understanding mine is a 1993 model which seems to be an oddball year, if I do order some parts from ScottyB I would like to know what the heck I have got and getting the correct parts.

[JohnnieB]

This site might help you identify your cart by the serial number. http://www.shopezgo.com/customer-ser...ialNumber.html

Fortunately, EZGO didn't re-invent the wheel every year like the automakers did and most parts of the drive system are interchangeable across the years.

Don't worry, Scotty knows what will work in your cart.