Ok. Once I started and ran the engine that first time, I haven’t seen -20 again. It just seems to stay around 0 all the time until I turn on the position lights -3 to -5 and the landing light is around -10 to -12. This is all with the engine running. I flew it about an hour this afternoon and nothing really changed during that time, around 0 @2350 rpm and the same discharge on the lights -3 to -12.
At this point it just seems like the generator is doing much if anything. Is there a way to check the generator output while running, other than the ammeter?
Remember I did put brushes in it a few months ago and it needed them, but the battery has been hooked up backwards from day one.
Sorry if I seem all over the place. I’m sure you’re frustrated with me by now.
Thanks for your help,
Brent
Battery Questions
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8209
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- Name: Brent Wilson
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6643
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- Name: John C
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Re: Battery Questions
Start with the basics. With all the accessories off, engine off, master on. The meter should not flinch when you turn the master on, unless you have something drawing current. If everything is off nothing should be drawing current. If it doesn't say zero, find out why. (Disconnect battery lead at regulator to eliminate (or convict) the reverse current cutout. Next, turn on the landing light. How much does it draw? (How much should it draw? About 20 amps for the 250 watt Grimes.)
Next, isolate and test the generator using the procedure in the other thread I referred to above. Flash the field if indicated. If you get through that, open the regulator and confirm the voltage and current contacts are closed. Check the resistance from the F terminal (with nothing connected to it) and ground. Confirm the case of the regulator is grounded. Confirm the reverse current contacts are open. Confirm the BAT and ARM terminals are connected to the battery (via the bus) and armature respectively. When the master is on the BAT terminal and the battery itself should have the same voltage, about 12.5 for a charged battery. (A dead battery will not affect the operation of the generator, in fact, you could run everything without the battery as long as you're willing to put up with low voltage below cruise RPM.)
If everything checks out and it still doesn't charge, take the top cowl off and run the engine with the regulator cover off. Observe the contacts and monitor the voltage between ARM and ground. Try to figure out what's not working as it should. When the voltage reaches about 12.5 the reverse current contacts should close and the ammeter should show a change toward the positive side. (It may not show a positive value, depending on the load and RPM, but should move toward the right.) (Prior to this point the meter should not change at all unless you add or remove load.) When the voltage reaches 13.8-14.2 the voltage regulator contacts should start to vibrate and the voltage should stabilize.
Next, isolate and test the generator using the procedure in the other thread I referred to above. Flash the field if indicated. If you get through that, open the regulator and confirm the voltage and current contacts are closed. Check the resistance from the F terminal (with nothing connected to it) and ground. Confirm the case of the regulator is grounded. Confirm the reverse current contacts are open. Confirm the BAT and ARM terminals are connected to the battery (via the bus) and armature respectively. When the master is on the BAT terminal and the battery itself should have the same voltage, about 12.5 for a charged battery. (A dead battery will not affect the operation of the generator, in fact, you could run everything without the battery as long as you're willing to put up with low voltage below cruise RPM.)
If everything checks out and it still doesn't charge, take the top cowl off and run the engine with the regulator cover off. Observe the contacts and monitor the voltage between ARM and ground. Try to figure out what's not working as it should. When the voltage reaches about 12.5 the reverse current contacts should close and the ammeter should show a change toward the positive side. (It may not show a positive value, depending on the load and RPM, but should move toward the right.) (Prior to this point the meter should not change at all unless you add or remove load.) When the voltage reaches 13.8-14.2 the voltage regulator contacts should start to vibrate and the voltage should stabilize.
John Cooper
www.skyportservices.net
www.skyportservices.net
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8209
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- Joined: Tue May 01, 2018 7:00 am
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Re: Battery Questions
Thanks John.
I will be out of town working for a couple of weeks, but as soon as I get back I will start troubleshooting again and report out what I find. I’m sure it’s something simple, I just haven’t hit on it yet.
Thanks for your efforts!
I will be out of town working for a couple of weeks, but as soon as I get back I will start troubleshooting again and report out what I find. I’m sure it’s something simple, I just haven’t hit on it yet.
Thanks for your efforts!