Testing for Battery drain

[fgutie35]

SInce you want to keep it simple, here are three very simple ways to check for what you want to know.
1.- to check if your alternator is actually charging the engine battery, turn the engine on (with another charged battery), then place a flat screw driver on the back of the alternator very close to the shaft, but without touching it. If the shaft is magnetized and attracts the screw driver, then your alternator is generating voltage.
2.- to check if there is a load or short on the circuit draining the battery, (with another charged battery) connect the positive lead to the positive post on the battery, then very gently, place the negative lead on the negative post on the battery. If there is a spark, then there is a load or a short somewhere in the circuit. The amount of spark will determine the severity of the load or short.
3.- lastly, to check if your battery has bitten the dust, place your battery on a good working charger and open up the caps like if you were to put water in it. Leave it uncover for several minutes, then look into the holes and see if you see bubbles. If you do see bubbles in at least one hole, then your battery is on its way to the grave. If all of them have bubbles, then is a goner. Hope this helps!

[Oz]

From: HeavyHaulTrucker
Sent: 8/10/2004

Sob said:
"The only difference that I can possibly think of between now and the times it went dead is that I was running off the aux tank when I shut it down when the draw was present and I was on the main tank when I shut it down after Williamsburg and going to the ODW this weekend (it started fine after sitting 3 days there too whereas before, it would have been dead).  "

Sob, unless I miss my guess, I think you may be onto something.  You might want to check to see if the "hot" lead on your tank switch is connected directly to battery + or if it is wired through the ignition switch.  If it is connected directly, then I think you have found your drain... the tank selector solenoid.  I believe that, with your Winnie, the selector valve has to be powered to select the Aux tank; no power to it selects the main tank -- just like mine.

John

This problem existed with my first 1974 Indian.  Never did get to figuring it out.  BUT... I have the exact same problem with my current 1974 Indian.  So, I definitely defined the drain as coming from the aux tank elecrical system.  That's the issue which prompted me to start this topic and, although I now know where the problem lies, at the time, I didn't even know how to test for a drain or what circuits needed to be tested. 

Thanks for the replies.  These tips are a great help!

[DaveVA78Chieftain]

This problem existed with my first 1974 Indian.  Never did get to figuring it out.  BUT... I have the exact same problem with my current 1974 Indian.  So, I definitely defined the drain as coming from the aux tank elecrical system.  That's the issue which prompted me to start this topic and, although I now know where the problem lies, at the time, I didn't even know how to test for a drain or what circuits needed to be tested. 

Thanks for the replies.  These tips are a great help!

Mark,
"BUT... I have the exact same problem with my current 1974 Indian."

The problem is just what John said.  The power to the tank select switch needs to be a switched output from the ignition switch.  That is the "I2" position on the switch.

Dave

[Winnebago]

After pulling every fuse, isolated the cause of house battery drain to the 0nan generator (generator is off). Seems to draw about .5 amps. Has anyone else encountered this? Any ideas? I'm thinking maybe a bad starter switch? Fuel pump? Or, maybe the wires that go to the generator start solenoid were placed wrong?

[Froggy1936]

When testing for a draw or a short, Disconnect negative battery terminal place a test light between batt terminal and cable If there is a draw or a short the light will light , Start disconnecting items or pulling fuses (start with the one you suspect ) When the short/draw is located the light will go out, Remember analog clocks are a permanent draw ! It is also a good idea to leave things disconnected as there may be more than 1 short/draw  A Short will make a large flash when touching batt cable to batt post , A draw will make a smaller spark depending on what it is ! Also a two terminal turn signal flasher can be used in place of test light (for  persons with good hearing) Good Luck

[DaveVA78Chieftain]

One has to know what model of Onan Generator you have.  There are literately dozens of Onan Generator designs.

[Winnebago]

Onan model #: 4.0BF-3CR/16002B

[DaveVA78Chieftain]

Manuals are in the Free manuals section.

Do you have the Deluxe Remote Control Panel on the dash?


If so, then the voltage meter is always looking at battery voltage.  You can pull fuse F1 on the generator to eliminate that draw.

If K2 relay is sticking or CR1 is shorted, then the ignition circuit is always energized.  You can pull fuse F2 on the generator to check to see if the ignition circuit is energized.

If K1 relay is sticking, then the generator would be drawing current though the windings.

Dave

[Winnebago]

Thanks for all the advice!
After inspecting generator wires, CR1 diode wire was not connected. Had shop test and confirm bad diode. Replaced diode. Couldn't start generator. Diode began to smoke--fried.  Long story short, last fall the shop had miswired the start solenoid (likely causing the diode to fry). Knowledgeable shop guy took care of it and changed solenoid wires around. Put in another new diode. No more battery drain!

[Winnebago]

Dave, Standard remote (though can't get that to work).

[DaveVA78Chieftain]

Glad they were able to figure it out.  Sounds like the CR1 diode was in series with the K1 relay contact such that it was part of the start circuit.  Given the generator is used as a motor for starting, that is way to much amperage for the diode.  The CR1 diode is only used to provide a path for charge current (1 to 1.5 amps) to flow back to the battery when the engine is running.