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249D Parasitic drain

Arny L

Senior Member
Joined
Sep 23, 2020
Messages
406
Location
canada
Don’t forget the key switch is spliced into the monitor circuit. Before you condem the monitor or ECM, the key switch should also be unplugged. You don’t want to buy an new monitor, and still have a draw, to find it’s a key switch.
 

benbuilder

Active Member
Joined
Jan 7, 2024
Messages
32
Location
Ma
I unplugged the Machine ECM. With the monitor fuse removed. See pict
ecm disconnect.jpg
I then, with my test light, again checked for the drain.
The same thing happens with the test light.
If i keep the ground of the test light connected to the negative cable, then put the point of the test light on a machine ground, the light will light momentarily light then fizzle out. if i let the machine sit for a bit then do the test, the light is a bit brighter and longer but fizzles out. In neither case does the light stay on for more than a split second.
I did not disconnect the key switch as that is another process.
 

Arny L

Senior Member
Joined
Sep 23, 2020
Messages
406
Location
canada
You have to have the fuse in place , every time your checking a circuit. Check each circuit separately, if you are checking ECM, monitor and key switch pugged in. Checking key switch, ECM and monitor plugged in. You remove the fuse for the disconnect, but replace it when checking for draw.
 

benbuilder

Active Member
Joined
Jan 7, 2024
Messages
32
Location
Ma
Maybe i misread post 79, i thought i was to have the fuse removed.
I will go retest.
But, right now with the fuse removed-which means the monitor is not in play, and the ECM disconnected. I do have the test light still lighting momentarily. Is this a flag?
 

Nige

Senior Member
Joined
Jun 22, 2011
Messages
38,773
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G..G..G..Granville.........!! Fetch your cloth.
Sorry if I caused any confusion. In an attempr to prevent any damage to expensive electrical components I suggested removing the fuse before connecting/disconnecting either ECMs or the Monitor Panel, just in case you get a spark somewhere.

The fuse has to be reinstalled before carrying out any test.
 

benbuilder

Active Member
Joined
Jan 7, 2024
Messages
32
Location
Ma
Why test light when you has multimeter?-For me i am more comfortable with the light. Remember, i am not you guys. I am not confident. I will try to use it more

I installed the fuse. ECM disconnected. the test light shines bright and constant. I guess that means i need to
1. put the ECM wires back on
2. Pull the fuse,
3. take apart the console on the left side of inside the cab and disconnect the key switch.
4. Put in the fuse
5. check for drain
??????????

Thanks again for the patience and help
 

Arny L

Senior Member
Joined
Sep 23, 2020
Messages
406
Location
canada
Why test light when you has multimeter?-For me i am more comfortable with the light. Remember, i am not you guys. I am not confident. I will try to use it more

I installed the fuse. ECM disconnected. the test light shines bright and constant. I guess that means i need to
1. put the ECM wires back on
2. Pull the fuse,
3. take apart the console on the left side of inside the cab and disconnect the key switch.
4. Put in the fuse
5. check for drain
??????????

Thanks again for the patience and help
Pull your fuse before connecting ECM, was monitor plugged in when you did this test? If yes, then it’s coming down to monitor or key switch. You just eliminated the ECM, congratulations.
 

benbuilder

Active Member
Joined
Jan 7, 2024
Messages
32
Location
Ma
Yes the monitor was plugged in.

I just pulled the fuse, going to take apart the left side now

Thanks
 

benbuilder

Active Member
Joined
Jan 7, 2024
Messages
32
Location
Ma
Took apart the left side, removed the fuse, disconnected the ignition switch. installed the fuse and tested for the parasitic drain with the test light, sorry forgot to use the meter. Light stays on
monitor and ECM were connected.
So that means the monitor, right?
 

Arny L

Senior Member
Joined
Sep 23, 2020
Messages
406
Location
canada
Took apart the left side, removed the fuse, disconnected the ignition switch. installed the fuse and tested for the parasitic drain with the test light, sorry forgot to use the meter. Light stays on
monitor and ECM were connected.
So that means the monitor, right?
I would say all testing points to monitor. Sometimes its good practice to redo tests just to rule out confusion. Since its all opened up. But I would be confidant in results. Does it make sense.
 

Nige

Senior Member
Joined
Jun 22, 2011
Messages
38,773
Location
G..G..G..Granville.........!! Fetch your cloth.
I know you had some doubts right back at the start of this thread regarding the efficiency of your master switch as in "were the contacts opening correctly when the switch was moved from ON to OFF.?"

Did you ever resolve that issue to your satisfaction.?

If so you can eliminate the parasitic drain without the need to replce the Monitor by turning the master switch to the OFF position any time you are going to shut the machine down for an extended period. A replacement Monitor was about $1500 the last time I saw one priced.
 

Arny L

Senior Member
Joined
Sep 23, 2020
Messages
406
Location
canada
Thanks Nige for all your help, with electrical diagrams and knowledge. You make it easier for all of us.
 

benbuilder

Active Member
Joined
Jan 7, 2024
Messages
32
Location
Ma
I cant thank you enough for the help you have all given me. especially Arny L and Nige. And for not giving up on me. I know i like to help out in other forums where i know something that can help others. But this was beyond that. Almost 100 posts to get through this.

I know the monitor ia 1500.00 but its a good machine and low hours so i just may do it. I will keep you posted. Thanks again.
 
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