Intermittent starting problems

[jnisley]

I was having intermittent starting problems on the last leg of a recent flight, I had full power (12+volts) in the cockpit but when I turned the key everything went black, when I released the key the power came back, the first thing we did was boost the battery (no change), then we load tested the 2 year old Concorde battery (it tested 100%) I made sure all the large terminals were tight on the battery and the solenoid (they were) after doing all this it started fine (several times), so I flew home. The first time I tried to start if right after shut down it didn't start but a minute later it did but it didn't the third try.

 

The next day it still wouldn't start so I removed the master solenoid and found that the small jumper wire that goes from the large post to the small post on the battery side of the solenoid (see attached photo) was broke at the connector but held to the post by the rubber boot, I haven't flowen the plane since but started it multiple times without any issues. Can someone tell me what that jumper wire does?

[jnisley]

Here it is

[Alan Fox]

Yes the solenoid is energized by providing a ground , so the solenoid  has to get its power to one side of the coil..... That jumper provides the power...

[DrBill]

I had a similar problem but since the battery was 5 years old I replaced it.  Problem never came back. But I took the battery home and used it on my whole house generator and as a portable jump battery (with 100Amp  connectors to a pair of battery jumper clamps).  It was then I noticed that one of the terminals was partially stripped thereby not providing good contact all the time.  I temporarily fixed it with a couple strands of #24 solid copper between the bolt and contact to fill the gap and make a better bite on the threads.  At Homecoming I talked to the Concorde guy about this and he suggested getting the right HELICOIL for the job and that is what I did for the permanent repair.

Bill

[jnisley]

Would a broken but touching jumper wire make enough contact for the solenoid to close and provide 12 volts of current to the panel but not enough to provide the draw needed to turn the starter?

[Alan Fox]

no

[N201MKTurbo]

The problem you describe would most likely be caused by a poor ground connection at the battery. It happened to me once where it was the connection between the shelf the battery ground strap is hooked to and the fuselage.

If it does it again, have someone measure the voltage between the ground post on the battery and one of the Southco fasteners on the access door, whale the starter is engaged. If this voltage is greater then a few tenths of a volt you have a problem.

[tony]

I had the exact same problem.  The electrical connection between the shelf and fuselage degrades over time.

[Hank]

It's nothing that can't be fixed by removing the wire and scrubbing things with a piece of scotchbrite can't fix. Check the end of the wire itself, too.

[Guest]

Here is the troubleshooting section from Skytec, applicable regardless of starter type.

http://www.skytecaircraftstarters.com/Troubleshooting.htm

Clarence

[jnisley]

Thanks everyone!

[jnisley]

We finally found our intermittent starting problem, the starter is shorting out but only after flights an hour or longer while it's still hot.

[Marauder]

We finally found our intermittent starting problem, the starter is shorting out but only after flights an hour or longer while it's still hot.

Interesting. Learn new troubling shooting stuff all the time.

Sent from my iPad using Tapatalk

[RobertGary1]

I had the same issue. I sent the starter to SkyTech and they fixed it inexpensively.

-Robert

[jnisley]

A new Sky-tec is on order.