Bad Starter Relay?

alpinelakespilot2000 · #1 03-01-2015, 02:33 PM

Need help troubleshooting...

Went to start up today and, out of the blue, could barely get the prop to move. It would move maybe 20-45 degrees and then seem to get hung up. After a couple seconds with the starter switch engaged I would get a bunch of clicking noises on the firewall and still no more movement on the prop. I tried this 3-4 times all with the same result. Pulling the prop through by hand felt normal... nothing binding up.

I have about 200 hours on everything, have never had cranking issues in the past with my SkyTec. When I pulled the cowl I checked battery voltage and it showed 12.4V, even after having tried to start the plane 3-4 times. So I'm thinking the issue is downstream of the battery. Further, based on an old thread started by Paul Dye, I'm very suspicious of my starter relay. http://www.vansairforce.com/communit...ighlight=relay. Except that this happened with no warning for me, my situation seems similar.

I'm planning to at least try cleaning all the big power wire terminals first, but does the above sound like a starter relay issue to you? It seems like not very many hours for it to fail, but perhaps I wasn't careful enough about not letting the terminals rotate while tightening the cables down when I first installed it.

Regardless, if it is the solenoid, Van's number is 24021 http://www.vansaircraft.com/cgi-bin/...oduct=start-sw and I think I found the same thing/same number at Napa for $24. http://www.napaonline.com/Catalog/Ca...021_0144317761 Just want to be sure they are the same.

Thanks for any help.

Vlad · #2 03-01-2015, 03:09 PM

The battery is about to die is my guess.

Jesse · #3 03-01-2015, 03:14 PM

My guess would be the battery as well. With no load, 12.4V doesn't mean it's good. I'd put a charger on it for a while and see how it cranks then.

SmilingJack · #4 03-01-2015, 03:16 PM

Quote:

Originally Posted by Vlad

The battery is about to die is my guess.

I agree wit Vlad.

My first flight was 9/2010. In the last couple months I noticed what you described and started to think....gee....why are my Pmag's not firing this engine off on 2 blades? And why is this thing starting to get suck?

Yesterday I changed the battery and today when I jumped in the airplane and pressed "START" - I barely saw 1 blade and the airplane was running!

It had so much cranking power I could feel a major difference.

Voltage? Not issues with the old battery. Probably 12.8+. The old batter just lost its cranking amp capacity.

flyinga · #5 03-01-2015, 03:20 PM

Put your volt-meter on the battery and (try to) engage the starter. If it goes below 10-11v, it's your battery.

Ironflight · #6 03-01-2015, 04:15 PM

Another simple way to check if it is the relay is to build a big "U"-shaped jumper that you can use to jump across the starter solenoid. Stand well clear of the prop, ignition absolutely, positively, no kidding OFF (disconnect the plug wires to make sure), and then jump across the relay. If it spins - great, then the relay is the problem. If not, then it is somewhere else.

Sounds more like battery to me as well, with the time you state on the components, but worth checking.

alpinelakespilot2000 · #7 03-01-2015, 04:20 PM

I'll check it, but it's a one year old Odyssey that has never had a problem cranking strong (I only replaced the original because I had been troubleshooting a different issue.). 2 days ago it cranked strong too. Plus, why would I be getting the clicking noise on the firewall right where the relay is? I've had a weak battery before that did not exhibit these symptoms. The symptoms I described are pretty similar to the thread identified above.

But, again, I'll hook up the voltmeter first and see what happens when I engage the starter. If that's not definitive, though, the solenoid at $24 seems the cheap place to start.

dlloyd3 · #8 03-01-2015, 04:37 PM

That clicking noise is the starter solenoid cycling in and out due to marginal voltage. Push the start button, solenoid engages and sends voltage to the starter, voltage drops due to load, the solenoid drops out due to low volts (click). Once it drops out, voltage rises, and reenergizes (click). Repeat several times (click, click, click). Sooner or later the contacts arcing at high amps will weld themselves together. Then you will have a bad starter solenoid.
Might be a bad connection but most likely the battery.

alpinelakespilot2000 · #9 03-01-2015, 04:41 PM

Quote:

Originally Posted by dlloyd3

That clicking noise is the starter solenoid cycling in and out due to marginal voltage. Push the start button, solenoid engages and sends voltage to the starter, voltage drops due to load, the solenoid drops out due to low volts (click). Once it drops out, voltage rises, and reenergizes (click). Repeat several times (click, click, click). Sooner or later the contacts arcing at high amps will weld themselves together. Then you will have a bad starter solenoid.
Might be a bad connection but most likely the battery.

OK, You guys have me temporarily convinced to start on the battery side. Thanks.

JohnInReno · #10 03-01-2015, 04:52 PM

Quote:

Originally Posted by alpinelakespilot2000

I'll check it, but it's a one year old Odyssey that has never had a problem cranking strong (I only replaced the original because I had been troubleshooting a different issue.).

I managed to destroy a PC680 by religiously using a battery tender after every flight. Odyssey had a list of acceptable battery tenders and the one that I was using was emphatically not acceptable.

The symptoms were as you described but a load test after charging dropped the voltage to about 8 volts in 10 seconds.

I stopped using the charger and have not had any problems since.

Just a thought.

john