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No battery charge!

HDDAHL

Active Member
Help! Only 9 hobbs hours.
Flew this AM; 10 minutes into the flight I noticed a dischsrge of 8 amps from the battery. Voltage was 11.5. Skyview system. Don't know whether no alternator from startup, was concentrating on elev indicator. Had used the battery for some configuration activity, maybe 30 minutes with a 4 amp discharge, prior to flight but plenty of oomph when starter engaged. All fuses good and no obvious wiring issues.

Has anyone had regulator failure? Don't have a good idea concerning how to diagnose this problem - alternator hard to get to!:mad: I have the cooling shroud on the regulator.

Any ideas welcome. Would hate to buy a new regulator just to see if that's the problem!
 
Check to make sure the connector on the regulator is fully seated. Same for the connector where the alternator and battery wires go into the circuit board in the instrument panel. Check the fuses to be sure they are not blown and that they are seated properly. Those are the obvious things to check.

Further diagnostics can be perfromed with a multimeter, and/or an ocilliscope. Probably Joe Gores will check into the forum later and give you some good advice. He is our resident electronic expert!

The good news is that this is probably an issue external to the alternator. I haven't heard of any alternator failures at all.
 
Check to make sure the connector on the regulator is fully seated.
The good news is that this is probably an issue external to the alternator. I haven't heard of any alternator failures at all.

I agree with what BigJohn says above, but remove the big black regulator connector first and make sure the pins are properly seated in this connector because if they are not when you push the connector into the voltage reg a pin can be pushed out of the connector.

Tony
 
Once you have diagnosed/repaired the problem, set your low voltage alarm to warn you. I am usually seeing 12.3-12.5 main bus voltage just before startup. I think I set it to warn me at 12.2. I have ran the entire panel down to 10.8 without a problem. I noted this voltage on the panel in case of emergency. Normally I would try not go below 11.5.
 
No battery Charge

Thanks to all. The regulator was fried, so bad that the terminal clip was imbedded into the regulator housing by melting. Hope it was just a bad regulator, don't know what would cause it. Looked to be an internal short.

Doug Dahl RV-12, 9A
 
ANY CHANCE - - -

you are working with the early instructions and hooked up too many wires to the regulator ? ? ? ?

John Bender
 
Revision

I believe that John is correct. It seems there was a revision dwg. on the regulator wiring.

Jersey
 
No Battery charge

Only 5 wires; none to terminal L.

I wonder if the cooling air duct and shroud is actually supplying any air to aid in cooling the regulator. I note a significant pressure inside the upper cowling evidenced by a bowing of the opening at the top rear of the top cowling where the small plate is for removing hinge pins and filling coolant. This bowing is evident at cruise. Mounting is on the horizontal part of the firewall. There is no bernoulli effect for the air entering the cooling duct ( the small plastic hose going to the shroud).

Any thoughts?
 
I doubt the meltdown was caused by external heat. More likely an internal failure. A lot of us have the same installation, cooling duct, and electrical loads, and are not seeing meltdowns. I think if there were a lot of failures such as this VAF have a BIG thread about it! Good luck with your new regulator. Let us know how it works.
 
F Y I - - - -

I put some of these on recently because we have had unusually hot weather recently. The 150 F block is blackened, so that is as warm as it has gotten. Nothing extra like lights etc., and no cooling hose. Maybe this will help.

John Bender
419.4 hours


RV-12ThermalStrips7-17-12100_2256.jpg
 
Temp labels...

I use them in several places too. The only problem is that they are exposed to radiant heat and heat after shutdown which can be higher than internal temps. My pp 60a alt indicates 300F on the side closest to my #1 exhaust pipe. My fuel pump and mags indicate 225F. No cooling blast tubes installed.
 
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