GEM E825 Newbie

I am the proud owner of a 1999 GEM E825. I was told it needed batteries, so we installed them yesterday. I energized the system and error -16 appears and an obnoxious horn that I did locate next to the master contactor. I am not getting an over voltage. 72 volt registering on my Fluke. The main contactor will not pull in with the 72 volt coil. I assume it is bad. Would this cause the error code -16? Batteries are all wired properly. I am looking for my next step in sorting this one out.

I [U]thought [/U]the earlier GEMS weren’t 72v systems but something less (48v maybe) though I’m not 100% about that. If you installed 6 x 12v batteries in series and it wasn’t a 72v system that would be the problem.

Thank you for the response. My Gem has a 72 volt system in it. GE 72 v controller, Zivan NG1 micro upgraded charger and a 72-12v DC to DC converter. The only issue I a seeing at this point is the error -16 and beeping when the key is energized.
Charger is working and system volts are not over 76 volts. I fully charged the new batteries for the 1st time last night. The only schematic I can’t locate, is the GE controller. I believe the issue resides there.
Any thoughts?

Hmm, you’re now a bit outside my area of expertise. The earlier controllers ARE programmable and there [B]may[/B] be a setting to determine what constitutes “overvoltage”. If it’s set too low for some reason, then it would throw the -16 error. The controllers “reboot” whenever you cut and then restore the power (which presumably would have been done (I HOPE!!) when you replaced the batteries.

I believe I need to replace the GE Controller. It appears the error code is derived from it. I have been rebooting the system and it did not help.

You might first want to call Ride-4-Fun and/or talk to Marlon (you can find him on this newsgroup) about the controller issue first. Both of these parties do a lot with reprogramming controllers and might have additional insights. I believe R4F also rebuilds them if you need to go down that road.

hi Tony… welcome… I just drive my GEM car and haven’t had the problem you are having… not sure if R-4-F is open on Saturday… maybe GEMmechanic will weigh in… if not drop do to the forum and repost your question… on Monday call Lee at Gem Car Parts Direct | The Nations #1 Source for Gem Car Parts… 888-677-4961… he can probably get you on the road quickly… I believe Marlon is still recuperating from an accident


Thanks for the info. I will look into that. I had sent my controller to an electronics specialist and he could not help. Just got it back and would like to have it looked at by someone knowledgable in these.

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Wow, this is my 500th post! It has been a long three years on here. 72 volts is actually a bit low. Fully charged and settled, the batteries should read 75.6 volts,which is 12.6 per battery. If you get a -16, run the lights for a minute to reduce the “surface charge” on the batteries. There are numerous companies that repair GE controllers. RFF is the best known.


CONGRATS GEMmechanic on the 500

I sent the controller in to Flight Systems. It was diagnosed as a bad potentiometer and they refurbed it. Put the controller in last night and it runs! Everything works great! Now I have a new issue ( or I believe it’s an issue). The car runs but the differential sounds very loud. Almost like a metal snow shovel on cement constantly ( if you understand what that sounds like). Breaks are not stuck, sound is in diff for sure.checked the oil and it looks fine. I think I’m going to open the diff this weekend and inspect the bearings.

Tony… glad you’re back on the street… did you check the oil level? maybe you only need to put oil in it… again I just drive my car and can’t fix it


I replaced the oil with 140 weight to see if it would quiet the trans axle down. To no prevail, I plan on removing motor today and possibly rebuilding front diff. Not sure what to do?

My issue was a bad motor! Bearings were shot. Rebuilt it and it runs like a champ!