2000 GEM dead after Radio install

Hello to all, New to the Forum and new GEM owner. I recently bought a 2000 E825 4 seater for what I think was a fair deal. Batteries are 7 months old new tires and rims with quick charger. But I have created my own problem I believe. I see myself as competent in the area of vehicle mechanics but no gas tank is new to me.

As for my problem, My GEM has done very well except for initially having a problem with a loose ignition wire on the keyed switch in the column. I corrected that and it has done well. My wife said she wanted a radio. And me being a good husband said of course I have done those a hundred times. I installed marine speakers in dash and a head unit in upper dash. I was pleased and then went to the wiring. My car has a Sure Power converter so wiring is not to PWB as in most manuals. There are 2 loose wires with twin female spades one is for ground to firewall next to charger and one is blue with a violet tracer that splits off to second female spade. This wire measured out at keyed 12 volt so that part seemed straight forward.

Now murphys law got me. I did not have a 12 volt battery to install and assumed for testing purposes I could just run memory constant to the battery to test it. So I ran memory constant to battery positive of bettery just under hood against firewall. the radio powered and the display began to cycle on and off . When I saw this I knew things where not right so I disconnected this wire. All back to square one. Right?

No now the key will not jump the contactor I have checked all fuses including the 400 fuse. All are good. I am at a loss. I know the sure power converters have no external fuses but I know they can take small hits without killing them. I can still get headlights to power so I can assume the converter is working, Or could it be the controller. I am not sure what all this controls but I assume it is like a PCM in a car. Could me tying to the battery have killed it.

I am asking for help from the people with more time than I have with these things. Any advice or directions would be greatly appreciated. We would love to have this GEM running for my families camping trip in a few weeks. Thanks in advance.

Anybody have any ideas. I know you guys are GEM genius superstars.

The GEM operational system is not grounded to the chassis. It uses battery minus for return.

The DC/DC converter is grounded to the frame as in automotive applications… Many people use a seperate battery for the memory of their radio. I understand a 9 volt battery lasts a long time. If you used one of the cart batteries and grounded it to the frame you may have damaged the controller.

Lets start here:

  1. does the buzzer sound if you let the Ebrake handle down?

2 do you get a 4 code when you turn on the switch with the Ebrake handle up

3 does the 4 code go away and the display show normal when you turn the key on?

4 does the buzzer sound when you put it in reverse?

Current problem is this. I now have the bdi that flashes 100 and then 0000. The con actor does not energize. I seem to have 72 volts at the important spots. When I hooked up radio I used the 12 volt accessory wire from dc converter and ground off the frame which is with the 12 volt accessory wire. I took the constant power wire to the positive post on the battery under the hood close to firewall. The previous owner seems to have bypassed the brake switch which I am not happy about. He left me with very little to repair this bypass and make it back to factory spec. I am afraid I have damaged the controller. What does a remanufactured or new controller cost. I am sure it’s a boat load.

I get $350 plus 36 postage to remanufacture your unit. Turn around is 2 to 2 1/2 weeks

Note: sometimes it is a good idea to get professional help. Shot gunning without knowing what your doing can cost you more than having a
GOOD service man ,at least do a diagnostic.

Ok so poking around. I have 72 volts to pin 1 on controller, no voltage on pin 2 with or without key on. I am tracing wires back to 12 volt relay. 72 volts on COM pin, good ground, and when I jump COM pin to n.o. Post then I have 72 volts at pin2 bdi powers and vehicle will move. So now I have it down I believe to key on circuit. Voltage at wires if I jump the key switch is 24v. Any ideas. I feel very close.

Check your battery charger interlock circuit.

Also the little black relay to the right of the main solenoid relay. These puppys have a high failure rate.

Ok is the relay the one with 72 volts or is it the relay mounted to firewall with dial on it. I currently don’t use the Scott charger I use a separate rapid charger. Is there a way to bypass the interlock and if not how can I check it? Thanks for your help so far.

The one with the dial delays power shut off for 30 secounds is there a cube relay in the same area?

Most Schott chargers were replaced with Zivan. I’ve never seen one. Does it have 2 wires other than the output wires plugged into it?

What DC/DC converter do you have?

The little cube relay was a part of the DC converter upgrade. To test this out connect the 2 relay output wires together.

I will look at the charger. I have sure power converter, and I will look into the relay I know which one it is based on you description. And that is how I got the contactor to drop in was jumping that relay. I will check the charger interlock. I’ll let ya know what I find tomorrow thanks.

I seem to have 72 volts or better everywhere I should. 12v out to all 12 v circuits from school converter. Question I have is on key switch. Should voltage on key switch be 72v or 12 v. The other question I have is I understand the relay I have 72v supply (white) my load wire (gry/why), but then 2 grounds(12v black), and then -72v (grn). Any idea which wire triggers the relay? I ordered a new relay but would love to know I’m moving in the right direction.

I believe that relay was added with the DC converter upgrade.

I have the upgrade info on pfd that show the schematics for all 3 conversions.

Send me an email if you would like a copy.



Thanks I got the information but what it nor the factory schematic show is which wire is trigger. It is 12 volt coil relay. I have seen and have used relays that use switch to switch ground for relays which is great to avoid passing voltage through firewalls and possibly creating short. But can’t figure how 12 volt ground and 72 volt trigger the relay

If it’s a 12v coil, the 72v must go thru the contacts. Not the coil. Which makes sense.

I believe that 12v comes from charger contacts, thru keyswitch, to relay coil.
That pulls relay in, sending B+ to pin 2 of controller.

Ido when jumping 72 volt contact leads at the surepower dc/dc relay I get +72v to bring in contactor and in return get +72v to pin 2 of controller. The only thing is when I press go pedal motor controller activates but It sounds as if motor is bogging down and doesn’t have the ummpf to move cart. So at this point I believe the starter relay at the scene/dc converter is the problem and I have one coming. I am still confused as to the coil wires on the relay. Contact wires are explainable +72v supply and +72 volt load to controller. But the trigger wires are a -72v ground from B- at controller and -12v from dc/dc converter. I guess ground is ground but if this is 12v coil it should require +12v to activate it. Any ideas. I am going meter blind.

Doesn’t sound right.
B- and 12v ground are not the same.
Battery circuit should not be grounded to chassis.
Could be something wasn’t quite right before this issue.

Although, not good, I don’t see what could be damaged by your mis-connection. Other than radio or converter. :confused:

I am still confused as to the coil wires on the relay. Contact wires are explainable +72v supply and +72 volt load to controller. But the trigger wires are a -72v ground from B- at controller and -12v from dc/dc converter. I guess ground is ground but if this is 12v coil it should require +12v to activate it. Any ideas. I am going meter blind.[/QUOTE]

I read the trigger wires as coming from the 72 volts + and common ground from the Sure power unit.

I have the sure power read out schematic if your interested. I believe it would clear it up for you.


That would be appreciated. Firejpn@verizon.net. As for the ground wires 12v ground is from chassis thought the surepower converter. -72v is from B- post which is battery pack -. I am sure nothing is damaged as I can function all systems independent. I believe the relay May in fact be the culprit. All was fine prior to radio install and no wiring was touched except for attempt to grab constant power. Electric principles and theory I am good with deft got thrown with mixed voltage system.

Rodney sent me the schematic.


Do the relay signal path in blue

Its interesting. The pin out from the other brochure might also be of interest.