Blown Battery Contactor?

roadrunner20 · #1 10-06-2015, 08:50 PM

I was doing some battery power on EFIS configurations this evening. Apparently, I drained the battery power down. When I opted for engine start, the starter wouldn't engage due to low battery.

While trying to attach the charger clamp thru the cowl oil access door, I grounded the positive battery terminal to the FW ground. The battery reads 12.5 V, but I get no master power.

Did I just blow my battery contactor? FWIW, I can't remember whether I had a diode attached.

I've not had a chance to remove the cowl as it was getting late.
Just thought I'd get some advice prior to troubleshooting it tomorrow.

UPDATE: while attempting to do a battery contact, I inadvertently disconnected a quick connect. I've corrected this with encapsulating the quick connect with some shrink tubing to prevent this in the future. I'm also rigging a remote battery connect as others have suggested.

Neal@F14 · #2 10-06-2015, 09:51 PM

A couple months ago I thought I lost my master relay (battery contactor) too. Battery measured 12.8v with everything turned off but output side of the relay measured 8.7v with the master switch on and would only provide enough juice to click the starter solenoid once but the master relay stayed engaged. Turned out to be just a dead cell in my 3 yr old battery. I bought a new battery and new master relay but only ended up installing the new battery.

robertahegy · #3 10-07-2015, 05:40 AM

Something to consider for easier charging. I installed a 12V power socket in my RV that was fused and hooked up to the battery directly. I could hook up my Odyssey charger through the socket via the socket plug and not have to reach into the engine compartment.

Roberta

roadrunner20 · #4 10-07-2015, 05:57 AM

Thank you Neal, I will check that out.
Roberta, never thought about it at the time. I have 2 power outlets I could have used.

airguy · #5 10-07-2015, 07:25 AM

Quote:

Originally Posted by robertahegy

Something to consider for easier charging. I installed a 12V power socket in my RV that was fused and hooked up to the battery directly. I could hook up my Odyssey charger through the socket via the socket plug and not have to reach into the engine compartment.

Roberta

I did the same - reasoning that I would always park it with flaps down, and likely find the battery discharged in that configuration, I put a 1/4" headset jack through the fuselage wall where it will be exposed with flaps down and covered with flaps up. It is direct to the battery via a 15 amp fuse. Certainly not enough current carrying capacity for a jump start, but it's good for a 1 hour charge to crank.

lr172 · #6 10-07-2015, 01:58 PM

Quote:

Originally Posted by airguy

I did the same - reasoning that I would always park it with flaps down, and likely find the battery discharged in that configuration, I put a 1/4" headset jack through the fuselage wall where it will be exposed with flaps down and covered with flaps up. It is direct to the battery via a 15 amp fuse. Certainly not enough current carrying capacity for a jump start, but it's good for a 1 hour charge to crank.

That is a good idea. I just made up a molex connector and inline fuse directly off the battery. I tie wrapped it to the eng mount frame just inside the oil door. My plug for the sump heater sits there as well.

Mike S · #7 10-07-2015, 02:22 PM

The battery--actually I have two-- is in the back in the 10, I used the ring lug pigtail that comes with the charger to run forward through the baggage bulkhead.

Drill the hole large enough to get the pigtail connector through, then a split "O" ring to fill the hole/protect the wire. Bit of Velcro keeps them out of the way.

If the battery is firewall forward mounted, you can still run a pigtail to the oil door area.