My 2008 e4 has an intermittent problem that threatens to leave me stranded. When pressing the accelerator the contactor clicks but the motor doesn’t engage.
Both times I manually pushed the cart a few feet and then it worked normally.
Could this be a problem with brushes? Do you think it is landing on a “bad” spot on the armature?
Thanks for any suggestions,
Yep- Easy enough to check.
Which motor is this?
Have you noticed it has been down on power?
When was the last time you had it serviced?
If it is brushes and you continue to drive it in this condition there is a chance you can damage your controller too!
Standard 5hp. Normal power. Other than lube what service is suggested?
Maybe post a pic?
If you have a GE5 Long motor there will be a band clamp around the brush end that will get you a little bit of access for a peek inside. You should be able to see 3 without motor removal. Otherwise remove cables and 3 gearbox bolts and the motor comes out for full bench cleaning or transport to a service center.
A blast of compressed air to blow out the carbon dust is a good thing from time to time.
Make sure the brushes are free to slide in their carriers.
Inspect the armature for signs of shorting or just not clean.
It is as you describe with the band clamp. I will take the motor off and see what I find. I will post as soon as I can see the insides.
Tech tip #26 -
When removing the cables off the motor use a wrench on the bottom nut to hold it in place and turn the top nut. If you don’t you might spin the whole stud in the insulator which can crack it and spin the spot welded wires off the inside.
Result- A simple inspection turns into a brush replacement.
Problem is the bottom nut is fairly buried down in there and a normal wrench usually will not fit. Most hacks will just go for it anyway.
Consider yourself warned.
PSA: Wear an N95 mask, that crap is not something you want to be breathing.
That would be Tech Tip#14.
I usually just stand upwind… which in hindsight probably explains a lot.
I would also caution the motor is really heavy and a bit awkward to handle so be careful. I used a rolling floor Jack as a support (with a piece of angle iron to reach in and support it.)
Have the motor serviced asap. I just went through a similar situation on a 07 Gem I picked up a few months ago and ended up buying a new motor from Inwo.
Had the same intermittent power issues, then wouldn’t go forward and backward hardly at all.
Next thing that happened when trying to drive it back into the garage was what sounded like rusty brake rotors rubbing the pads + welding sounds, and my wife saying she things she saw a spark.
Pushed it back in, took the band off and small chunks of carbon and brushes and dime-sized piece of metal fell out.
Metal ended up being the bracket that holds one of the brushes.
Keep in mind I probably only drove this about 2 miles total since I got it in January. And the little testing I mentioned was only about a 20ft distance on the driveway/garage. Definitely could have been a lot worse than just the cost of a new motor.
So if you’re not sure if it’s ever been serviced, get it serviced
Thanks for all the help. I took the motor off, cleaned what I could reach, blew out a LOT of black dust, and checked the brushes (which seem to be good). After a test drive, I had no problems. I probably should have thought to tell y’all that even though my GEM is a 2008 the motor is. only 4 years old.
Should I still take it to a shop for service?
If it continues to work ok then it doesn’t sound like you need to.
That is just a general description for A range of service varying from giving it a little love to full on strip search and replace anything that is loose and worn out.
Who can do? It all depends on the skill set of the owner, tools at hand, and how much a person wants to get into it.
You did a basic inspection and blow out. You say it is four years new, but you saw how much carbon dust built up in there. I’d say it was time. Just this action is good for it.
Did you take any pics before putting it back together?
The next level would be to clean off the comms(where the brushes rub) but that is more involved). If there were grooves it might need to be turned but that takes special equipment.
Replacing the bearing if needed would also be a reason for taking it to the shop if you don’t have that tools to do that.
Otherwise, It sounds like you might have had a brush beginning to hang up, but just removing motor may have knocked it loose. For a motor to fully go dead it would have had to lose contact on two brushes.
Maybe you had a bad contact on the Field coils? Check the wires going to the top of the controller for corrosion. They are just push on spade connectors.
I’d say you did good but do a bunch of short test runs just to make sure.
A new long GE 72VDC from 2018? Don’t think GEM was using them anymore at that point. Thought all their vehicles were 48V and largely AC 3-phase motors by then.
New new (New Old Stock)? or New rebuilt? or just New to you, history kinda unknown?
keep 35 psi in the tires helps a lot
Easier to push it home?
I guess the same goes if you live in a hilly neighborhood. Always test run to the high ground.
Hard to push it home in my wheelchair, ergo my fear of being stranded.
The motor was installed (described as new) by the GEM dealer and came with a one year warranty, other than that I am not sure of its provenance.
I finally broke down and took it to the shop. The report is that the field coils have shorted to the case via a massive build up of carbon dust. However the brushes look new! Makes me suspicious.
Does anyone have one for sale?
I’m a little confused.
Last we heard from you (20 days ago) all was good.
Did something else happen?
I’d be highly suspicious about the field coils unless they damaged the motor when they took it out for inspection. Field coils shorted to case would be a different set of symptoms not to mention it would actually throw a code. If it were due to excessive carbon dust, Just blow it out!!! It doesn’t sound like a terminal situation to me.
Do you remember seeing anything on your display?
Think back to when you inspected the brushes.
checked the brushes (which seem to be good)
seemed to be lacking a physical aspect of “Pulling the spring back and making sure the brush slides in and out easily within it’s holder”. Maybe I should have been more specific but at least this is what the repair shop should have done when they disassembled the motor.
The problem reoccured within a few days. Yes, the brushes were almost as long as the holder and the springs moved freely, as did the brushes. I now suspect that the “new” motor from the dealer was in fact a poorly repaired older one. It was certainly shiny! The shop doing the work is the premier, 50 + year old industrial shop in Mobile and they had your same reaction, surprise that it wasn’t a brush problem.
Regardless, now I am paying for an overhaul including rewinding the coils.