Mep002a batt guage issue

[sjacobs1259]

Hey yall. So as stated in the title I have a problem with my battery guage well someing related to the guage. The guage works fine I've tested that and the charging system works its reading 27 volts. But at the wires goin to the guage I'm only getting 12 volts. Any idea what it could be?

 

[Light in the Dark]

Trace the circuit backwards, see where the voltage is changing. You have seen this gauge read correctly before, or this is a new machine to you? Is it hooked up correctly?

 

[sjacobs1259]

Trace the circuit backwards, see where the voltage is changing. You have seen this gauge read correctly before, or this is a new machine to you? Is it hooked up correctly?

I have seen the guage read correctly I tested it in a humvee yesterday and it works. Yes it is hooked up correctly. I've traced it to a point but I'm not sure where to go. I've tried reading the schematic but it loses me. Where does the signal originate. I kno it dosent come directly off the batteries. Is it the alternator, regulator? I kno its something simply but it's like I've been racking my brain trying to figure it out.

 

[Light in the Dark]

Well you say the charging system works and reads 27V... where did you get that figure from?

 

[sjacobs1259]

Well you say the charging system works and reads 27V... where did you get that figure from?

I put a multi meter on the batteries while it's running.

 

[Light in the Dark]

You need to test the DC charging system properly: https://www.steelsoldiers.com/threa...3a-dc-charging-system-test.94880/post-2212133

 

[Light in the Dark]

If you don't have the TMs for this set, you can download them here: https://www.steelsoldiers.com/threads/all-the-tms-you-need-to-work-on-the-mep-002a.155935/

 

[sjacobs1259]

If you don't have the TMs for this set, you can download them here: https://www.steelsoldiers.com/threads/all-the-tms-you-need-to-work-on-the-mep-002a.155935/
[/QUOTE
ok ill take a look when u get a chamce and see what i can find. Yea I've got all the tms for it.

 

[Ray70]

Inside the control box find TB-5 screw#8 and test DC voltage there, are you getting 12V or 24V?

 

[Ray70]

Also, when you checked the voltage, I assume you tested right at the gage? Where did you place your negative lead?
If I recall, the Batt gage grounds through the gage panel, you might want to verify you have a good connection between the gage and panel as well as panel to chassis/batt. neg.

 

[sjacobs1259]

Okay so I rechecked The gauge the ground the wiring I'm getting 6 V that's it. at the gauge It's 6 V at TB 5 post 8. It's 6 V and I'm assuming it goes into S1 at post 13 and 14. I'm only getting 6. Volts. There where do I go next?

 

[sjacobs1259]

Yo please forgive me I'm not an electrician. I'm a diesel mechanic I understand how to read a schematic but sometimes I do get turned around

 

[sjacobs1259]

Ok FINALLY FIGURED IT OUT this whole time its been a ground issue. It seems like the instrument panel and the instrument box assembly are not grounded or something.

 

[Light in the Dark]

The 00x machines require periodic inspection of grounds for this very reason, which I am sure is why Ray mentioned it in a previous post. Glad you got it figured out.

 

[Ray70]

There is a ground strap under the lower left rear corner of the control box. Check that.
It's a braid strap connecting the control box to the chassis right under where the connectors exit the rear of the control box.
I believe you should also have a connection from the battery - on the starter to the terminal block inside the control cube.

 

[sjacobs1259]

There is a ground strap under the lower left rear corner of the control box. Check that.
It's a braid strap connecting the control box to the chassis right under where the connectors exit the rear of the control box.
I believe you should also have a connection from the battery - on the starter to the terminal block inside the control cube.

Yea I found the ground strap this morning. So I took the box off. It was pretty ugly lookin. I had to cut one of the nuts off with a Dremel tool it was so rusted. Cleaned it all up put new nuts an bolt on it. And it works great. But now I see the system is over charging so i have to test the charging system. And I'm still trying to figure out what's up with my load meter. It reads at first then drop down to zero. It's it not one thing it's another lol.

 

[Light in the Dark]

Your gauge (and battery charging alternator) are working perfectly if it drops to zero. That means your batteries are charged and the system is maintained. If it was showing in the negative range, that means its discharging and running down your batteries

 

[sjacobs1259]

Your gauge (and battery charging alternator) are working perfectly if it drops to zero. That means your batteries are charged and the system is maintained. If it was showing in the negative range, that means its discharging and running down your batteries

Ii understand that. But the batt guage reads in the red. I was talking abt the ammeter. The are of the guage and the voltage at the batts

 

[Light in the Dark]

Sorry I read it quick on my phone, I thought it was the battery gauge that was levelling back to zero.

 

[Light in the Dark]

MEP-002a and MEP-003a DC Charging System Test

Testing the DC voltage regulator in 5 easy steps Step 1 With the set OFF, measure DC Voltage at the regulator wire that is marked with the red band. Should be around 24 to 24.5 volts DC...Is it?? Step 2 If so, DO NOT disconnect anything and start the generator. Now measure for DC Voltage at...

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