Golf cart running hot

[Arctic Fox]

Mrs Fox has a 36v E-Z-Go which has new batteries, and had a reconditioned motor put in about a year ago.

After any journey of more than a mile there is a smell (possibly hot oil?) coming from under the seat and the two plastic covers under the passenger side of the seat are hot to the touch. I assume that the larger cover hides the motor?

Mrs Fox does not drive at the cart's top speed so I do not understand why the cart is running hot. Any thoughts?

Thank you

[villagetinker]

Check the voltage across each battery with and without the charger connected, do the without test first. All batteries should have almost identical readings. Immediately after using the cart, VERY CAREFULLY check and see if any of the wiring or battery terminations are HOT. Call whoever installed the batteries if you find differing readings between batteries, or any hot connections. The next item to check would be excessive current draw to the motor, for this you would need access to a DC clamp on ammeter, mine is no where high enough rating for this application.
Hope this helps.

[SouthOfTheBorder]

OP,

Based on your description "hot smell" that starts after a mile or so I would check the brakes to be sure one or all are not fully released and dragging on the drum causing friction (heat). Many electric carts can produce enough torque to overcome the brakes even when fully on.

Electric carts do not have any oil except in the rear end gears. If you do not have any signs of an oil leak in the back then it is unlikely to come from there.

Other than brakes, unusual odor from electric carts is due to overheating, either within the wiring harness or or inside the motor. And the condition(s) that cause the overheating resulting in an odor will quickly cause a failure that prevents the cart from operating.

Don

[Arctic Fox]

unusual odor from electric carts is due to overheating, either within the wiring harness or or inside the motor. And the condition(s) that cause the overheating resulting in an odor will quickly cause a failure that prevents the cart from operating.

Thank you, Don

It is definitely a motor/electrics issue - I think the motor they put in may be too powerful for the cart's original wiring

[Arctic Fox]

The next item to check would be excessive current draw to the motor, for this you would need access to a DC clamp on ammeter, mine is no where high enough rating for this application.

Thank you, VT

Will have to call on my engineer friends as I have no such equipment myself. However, I do think it is a "too powerful" motor for the original wiring so your suggestion above is a good one

Foxy

[SouthOfTheBorder]

Thank you, Don

It is definitely a motor/electrics issue - I think the motor they put in may be too powerful for the cart's original wiring

Dragging brake(s) will cause the controller to satisfy the increase/current consumption need by the motor to maintain speed. Results in overheating both at the brakes and in the 36V portion, including the motor, of your drive system.

Who ever replaced the motor should be able to do a diagnosis pretty quickly.

Don

[villagetinker]

As a side note, the brakes failed on our gas Yamaha, on one of the rear wheels, the pads came loose from the brake shoes, and would occasionally get wedged between the drum and the shoes, so a noted above, have the brakes checked, been there and done that.

[Arctic Fox]

Dragging brake(s) will cause the controller to satisfy the increase/current consumption need by the motor to maintain speed. Results in overheating both at the brakes and in the 36V portion, including the motor, of your drive system.

Thanks, Don - good point

Will jack her up and see if all wheels spin freely

[PaulDenise]

You might go to Harbor Freight and buy one of those $10 infrared temperature guns and see what the temps are of the various components in the engine bay after it gets 'too' hot.

My bet is on the controller box that modulates the power from the batteries to the motor.

Another bet is that you have corroded wires someplace and the corrosion is causing resistance that is causing the heat. A cheap first thing to do would be to disconnect all the high amp wire and clean them and re-connect them.

[TechGC]

Loose battery connection would be the most common and due to the fact that it heats up so quick. Its not the controller for sure.

[Topspinmo]

Loose battery connection would be the most common and due to the fact that it heats up so quick. Its not the controller for sure.

Didn’t mention how old batteries or cables were? I was thinking cables internally corroded?

[Arctic Fox]

Batteries and battery cables are new, and tight, and there is no sign of any heat amongst them after running the cart

It is whatever is in the two black, plastic boxes under where the passenger sits that gets hot. The small box nearer the front (to which the forward/reverse lever connects) gets warm, but not that hot. We had that component replaced last year as, before that, it was definitely getting hot.

The larger box to the rear is very warm to the touch, which it never used to be. I have taken the cover off and there doesn't appear to be any damage or arcing in there, but I don't recall that one getting hot previously.

The person who fitted the new motor did tell Mrs Fox that she would have "the fastest 36v in The Villages" so I think the motor is too powerful for the original electrics and draws too much current, even though she doesn't go anywhere near full speed in it.

I shall be checking for binding brakes tomorrow.

[TechGC]

Batteries and battery cables are new, and tight, and there is no sign of any heat amongst them after running the cart

It is whatever is in the two black, plastic boxes under where the passenger sits that gets hot. The small box nearer the front (to which the forward/reverse lever connects) gets warm, but not that hot. We had that component replaced last year as, before that, it was definitely getting hot.

The larger box to the rear is very warm to the touch, which it never used to be. I have taken the cover off and there doesn't appear to be any damage or arcing in there, but I don't recall that one getting hot previously.

The person who fitted the new motor did tell Mrs Fox that she would have "the fastest 36v in The Villages" so I think the motor is too powerful for the original electrics and draws too much current, even though she doesn't go anywhere near full speed in it.

I shall be checking for binding brakes tomorrow.


Wrong motor for application.

[Arctic Fox]

Brakes are not binding, so we have Willy Willcoxon coming out on Monday to cast his expert eye over it

[PaulDenise]

Please do get back to us about what he finds.

[Arctic Fox]

Please do get back to us about what he finds.

Will do, but while we're waiting for Willie's expert opinion on Monday, let me run this past the electrical engineers out there:

It is the controller that is running hot, and the controller "meters out the battery voltage and current to the motor based on some type of operator input such as a throttle. This allows for the operator to control the rate of acceleration and deceleration as well as the rate of speed the vehicle moves at."

Assuming that the recently-installed replacement motor is too powerful (draws too much current) for the existing electrics, could it be that Mrs Fox's going at a reduced speed is actually causing the controller to have to do too much work?

[PaulDenise]

I am not an electrical engineer, but...

the controller is like a water valve that you can open and close or leave someplace in the middle. A 1/2 inch water valve can supply between 0 and 20 gallons of water per minute. a 3/4 inch water valve can supply between 0 and 40 gallons of water per minute.

Similarly, a controller can be small or big. A small one might provide between 0 and 100 amps, while a large one might provide between 0 and 200 amps (made up numbers).

A 'too powerful' motor cannot draw more power than the controller is designed to supply. If you have the same old small controller, a new 'more powerful' motor will only run as fast as the old one because it is only getting the juice that the old one got.

If your controller is getting hot, it is possible that it is dying or that the connections are indeed corroded or loose or something. All the juice from the batteries to the motor goes thru the controller.

[Arctic Fox]

If your controller is getting hot, it is possible that it is dying...

Thank you for the explanation, Paul

The cart is 18 years old so it is quite possible that the controller needs to be replaced.

(Mrs Fox is even older, but I'll hang on to her a bit longer)

[TechGC]

Your only as strong as your weakest part. A motor can try and pull a lot of amps, but the weakest link in the chain will show up. Controller can and will get hot with the wrong combo, but does have whats called, "thermal shutdown" built into it. Thus, if it gets internally to hot, it will shut down. See it way to often that a motor is put in, not for the good of the customer, but good for the installers pocket.
Now you could get talked into a controller that has more amps, and that will end that issue and the issue may go to the next weakest link. Controllers do fail over time, but not the way you are describing.

[Arctic Fox]

We have Willy Willcoxon coming out on Monday to cast his expert eye over it

I know you are agog with indifference, so here goes:

Willy found a couple of loose wires in the controller so tightened them up, and checked all of the battery connections.

Unfortunately, what we all thought was going to be the quick fix turned out not to be the case, and the smell of hot electrics came on quicker and stronger next time we went out in the cart.

Willy returned and replaced the solenoid in the controller. That seems to have done the trick. There is still a slight smell of hot electrics (but only when you lift the seat, so maybe that is normal) and the covers on the fwd/rvs and the controller are only warm, not hot.

[PaulDenise]

Thanks for the follow-up. Interesting, and, as usual, it was not one clean thing but two.

Also, at 18 years old and with only 36 volts, it might be time to keep an eye out for a good deal on a newer 48 volt cart.