GEM 2000 e825 error code of -51

I have a 2000 e825. Batteries 6 months old. I am getting an error code of -51. I have turned off the master switch and turned it back on after a while. Batteries are charged. Any help would be greatly appreciated.

At what percentage of charge do you start getting the 51 code. You should not run the battery pack below 50%.

What Brand and Model # are your batteries? Be Specific.

[quote=OLD HOUSEBOATER;26329]At what percentage of charge do you start getting the 51 code. You should not run the battery pack below 50%.

What Brand and Model # are your batteries? Be Specific.[/quote]

They are Crown deep cycle model #cr-gc150. I normally never take it below 70 percent. Just went to check the percentage and there is no display at all now. There was yesterday

  1. Check all connections for bright and tight.

2 Check Voltage of each individual battery when you get the 51 code

3 Check specific gravity of all Cells.

Even though your batteries are only 6 months old you could have s dud.

I will do that and let you know what I find out. Thank you!

I haven’t been able to check the batteries. Hopefully I can get to it this weekend. I did put it through 3 charge cycles and finally got the charge light to go green but the display will not light up and there still no power. Just wanted to let you know I am still in need of your advice if you will and will get the batteries checked as soon as possible and report back.

  1. Unplug the charger and put the parking brake handle down (with the key off)
    Does the buzzer sound?

  2. Pull the interlock wires out of the charger and jumper them and see if you have

I will do that.

I haven’t gotten the batteries checked as of yet. I did go through a couple more charge cycles and I now have headlights, horn and my display back. I tried the key off and parking brake down but no buzzer. The parking brake normally has a large click when pushed all of the way down. I have to have that click to get power. Currently it doesn’t click at all. Could that be related?


did you pull the interlock wires out of the charger and jump them?

Just for the hell of it shut off your main switch for 5 minutes.

Darn it. I totally forgot that one. I will get at that tonight and get back. Thanks so much.

Can you tell me exactly what you mean by jumper? I am not a very mechanical guy unfortunately.

Connect the 2 wires together with a short piece of wire.

New question. I still have the error code 51. Batteries all seem to test out fine. Lights, horn, etc are all in working order. One item that I notice is that I do not get that clunking sound when disengaging the parking brake. I always have to had to have that sound first before it would run. Is that something that I can look into?

Check voltage at controller.

I believe low voltage (error 51) keeps main contactor from clunking in.

I am afraid I am quite ignorant when it comes to repair. Where exactly do I check the voltage at the controller?

With voltmeter set to dc volts. Check from plus to minus terminals on controller. These are the main terminals that supply power to control thru fuse, main contactor or precharge circuit.

It must read battery voltage for -51 to clear.

Double check my opinions with Rodney.
I’m an electronic tech, but Rodney has the practical knowledge.:slight_smile:

Is the controller located under the dash or the seat?

Here’s a picture of mine.
Main terminals circled.

Need at least 60 volts dc to remove error -51