Troubleshooting starting problem

[piperboy84]

Was hoping for some pointers or confirmation that my suspicion that my starter is on its way out is correct, recently when I go to start the plane the prop will do a ¼ turn then nothing, like the battery was dead, if I continued it would do at least 4 or 5 quarter turns then fire up. I put a trickle charger on the battery thinking it was low but after fully charging I have the same issue. Today I did 3.5 hours of flying after fully charging the battery upon shut down I tried restarting and again it was the 4 or 5 quarter turns then bursts into life, I then put the trickle charger on the battery and it showed it as being fully charged. So unless there is anything else in-line between the battery and the starter would I be safe to assume the starter is on its way out? (it’s a Lycoming 0-360)

[A and C]

Piper issued an SB about the replacement of aluminum starter cables with copper cables, the symptoms you describe match those I have witnesses on a few Piper aircraft.

The copper starter cables solved the problem.

[piperboy84]

Its a Maule, will check the cables tomorrow

[stiknruda]

I'd also ensure that the earth connection (base plate to fuselage) of the starter solenoid was clean and shiny.

If it's been fine but it's now degrading it could be aluminium dash 4 cable but it's likely to be a poor connection. On mine the starter solenoid is generally the culprit!



Stik

[DeltaV]

It might also be worth having the battery capacity checked as it could be that that's on the way out.

[piperboy84]

It might also be worth having the battery capacity checked as it could be that that's on the way out

I wonder if the battery could drop a cell but still show as "charged" on the trickle charger i.e. all the good cells are charged but the bad one(s) are just ignored by the charger

[smarthawke]

I would start with having a known good battery fitted. It is quite possibly one duff cell that is letting the side down.

At work we now fit the Concorde RG-35AXC on PA28s. Maintenance free and loads of power.

[Maoraigh1]

If it's a 12v system, jump start from a car. If that works from the battery jumpleaded, it's the battery. If you still have the problem it might be the starter, or the solenoid or a lead connection. Or thick cold oil??

[Zulu Alpha]

Try working your way through this.

http://www.bandc.biz/pdfs/Starter%20Troubleshooting.pdf

[dont overfil]

Easiest thing to do is check the battery first. Bob can do it in minutes.

D.O.

[Dg800]

I wonder if the battery could drop a cell but still show as "charged" on the trickle charger i.e. all the good cells are charged but the bad one(s) are just ignored by the charger

Cells are connected serially to get to the 12v nominal voltage, if one dies there is no electrical continuity any more and the battery dies too. There is no way the charger can access a single cell.

Ciao,

Dg800

[Dan the weegie]

Also worth checking the output of the voltage regulator, it's a fairly simple circuit really :) not much between the battery and the starter other than the regulator.

My guess is the battery, as has been said before, put a power pack on it rather than a trickle charger and see how well it starts. If it's the same then it's not the battery :)

[cockney steve]

if one dies there is no electrical continuity any more and the battery dies
There, you make an assumption that a cell "dying" means it goes Open Circuit.....WRONG

It can go short-circuit or high -resistance as well as O/C...an open cell would leave the whole battery "dead", 'cos the "chain " of cells is broken.
A tired, high resistance "12v" battery will still read ~14V fully charged and will STILL light a few lamps etc. for a few hours with minimal volts-drop (down to ~12.....but bang a starter across it and it WILL curl up it's toes and sink to ~6-8V let go the key and recovery will be a few seconds to full volts but NO CAPACITY for large currents (around 150amps lock-draw, i'd guess)
Over-advanced ignition "could" give similar symptoms,but i'd expect to see the prop "kick-back" as opposed to just squeezing up to TDC.

Buy a cheap multimeter (or scrounge one )..check static battery volts , check cranking volts, check and compare volts at starter (main lead and if it's a pre-engaged type, fly-lead volts as well)
Starter can have a sticking brush or a load of carbon brush-dust tracking it down......otoh, it gould be pregnant (fxxed a while since)
A bit of common-sense , logical diagnosis could save you a chunk of money.....
I gave up arguing with smartasses who told me they needed"X" without explaining what led them to that belief.... flogged them "x" then gave the bad news that "well, actually, you needed a,y and z -X was OK so now you have your old one as a spare :) good for the bottom line!.

[Big Pistons Forever]

Just had the exact same problem on my Grumman AA1B (Lycoming O 235). The original 38 yr old starter solenoid had worn out and was not passing full current to the starter. You could tell it was the solenoid because you could hear it chattering. Even if it turns out to be the battery you should consider changing the solenoid while the cowl is off if it is the original one. They are not that expensive ($38 for mine) and it is a simple job.

[stevelup]

A tired, high resistance "12v" battery will still read ~14V fully charged and will STILL light a few lamps etc. for a few hours with minimal volts-drop (down to ~12.....but bang a starter across it and it WILL curl up it's toes and sink to ~6-8V

Concur 100% - our battery failed in exactly the same manner. It would charge 'normally' even when removed from the aircraft and connected to a charger.

Voltage off load was fine, and even on load it would light up all the lights and spin the instruments at the right speed. Within two or three seconds of using the starter though, it would be - to all intents and purposes - completely dead.

[piperboy84]

Put jumpers cables off the landy on it, and it fired up nicely, so replaced the battery (changed the oil and rotated the plugs while I was at it) and all is well again,

Thanks to all for the tips, its much appreciated.