Electrical system troubleshooting

I replaced my standard GILL-35 battery back in August, but I having problems with the battery being dead again. The plane still has the stock generator. I'm working with my mechanic on this, but I could use a how-to guide for troubleshooting this kind issue so I have a process to follow.

A side issue is that when I attempt to start the plane with the weak battery the bendix gear engages on the flex plate (?) but doesn't release. Is this normal, or an indicator of something else that is wrong? Is it OK to hand prop the plane with that gear engaged?

The Bendix does seem to stick a lot., but make sure your starter is alligned and the mount is tight.

A poor ground on a loose starter makes it feel as if the battery is down.

Gary

Bendix is designed so that once it is engaged, takes so many rpm from engine to disengage.Thats why once you get it engaged with almost dead battery, you have to pull engine and bendix thru while hand propping. If you ever get an engine started at a very low idle, you can hear the bendix still spinning until enough rpm is made to disengage. I don't remember if this is true on both the prestolite and Delco or just one of them.

Rod, If you have something draining the battery take the positive lead off and put an amp meter between the battery post and the positive wire. With everything turned off you should not show any amperage. If you are loosing voltage in the starter circuit put a volt meter at the starter lug and hit the start button. You shouln't have a very large voltage drop, maybe 2 or 3 volts. You might charge the battery good and then check the specific gravity. This is the best way I know to tell the condition of the battery. Starters can wear and start grinding also. If the battery is good and you don't have a significant voltage drop at the starter I would suspect the starter.

I had a skytec lightweight starter with the same symptoms. After fighting it I finally ordered a BC lightweight and with no other changes It has spun really well for over 150 hours! I suspect that the heat off of the front Cross over affects the windings? The grounding is essential on all the systems however.

Tim

I agree with Tim about grounding. I have found several A/C with no ground strap from the engine to the airframe. Installed a ground strap, problem solved.

Tim......how many hours on your skytec before you replaced it. I may have the same problem. My skytec was new, but 4 yrs. old, when I installed it and after about 150 hrs. I'm getting the "weak battery syndrome"......turns over sluggish, but not all the time. Wish I woulda put a B&C in to begin with.

The Skytec had only 120 hours on it! the problem was it had 6 years on it. Seams that (perhaps) they don't insulate their windings as well. I think the driving rain/ dust and other crap into the bendix is a contributor as well. The BC will fit behind the nose bowl and you can cover the hole!

Bill will stand behind his product! The money is well spent!

Tim