AOG - Battery/alternator/starter problem----solved :)

[Mike H]

One last idea! If you have a firewall mounted starter solenoid (some experimentals use the integral solenoid only) the you may be able to remove the power cable from the starter solenoid input terminal and relocate it to the output terminal that feeds the commutator. If there is room to do this you effectively are bypassing the integral solenoid and operate off of the airframe mounted solenoid only.

http://www.skytecair.com/Wiring_diag.htm

[Ironflight]

I've been just where you are, and I'd say the easy thing to T/S, and a very likely cause, is the firewall-mounted solenoid (as others have said). We confirmed this once in our case with a "U"-shaped piece of piano hinge pin as a jumper to jump around the solenoid (just hug the firewall, and keep the ignition off. Yes, you can probably source a replacement at the auto parts store.

Paul

[JordanGrant]

I'll try to test/jump/replace the airframe-mounted solenoid first. Since it's never been replaced, it might be the culprit (like in Paul Dye's thread above). Thanks for the data, Mike!

[bjb3013]

Any starter shop should have the starter mounted solenoid, it is from a Ford geared starter and is used on many cars and trucks, very common and easy to replace

Didn't I say this in post 5? Let us know what solves your problem, please.

[swordtail]

one or two flips of the prop will get it going, in a pinch revert to simply. fix it when you get home.

[Mike H]

Originally Posted by swordtail

one or two flips of the prop will get it going, in a pinch revert to simply. fix it when you get home.

It could also get you seriously hurt or killed. Hand proping an O-320 or O-360 is not even remotely close to hand starting a 65 HP Continental on a champ or a Cub. I know people attempt it all the time, some may even be successful, but I would rather fix the airplane than take the risk of being hurt or worse.

[Tom Martin]

First replace the solenoid. I have had several skytec starters rebuilt at automotive shops. Except for the casting all the electrical parts are automotive.
Then I would take a serious look at your alternator. I have 800+ hours on my rocket and for the last year the starts have not been great. I replaced the battery and that did not solve the problem. The charging voltage was lower then the 14.2 it used to put out but since is was higher then the resting battery voltage I thought all was well. I replaced the alternator 25 hours ago and the whole system is working much better. The old alternator has been rebuilt, new internal voltage regulator, and is sitting on the shelf waiting for the next sign of voltage under 14.2V.

[JordanGrant]

Troubleshooting this morning, thinking probably a starter solenoid, but...

1. Oil temperature sensor dropped offline yesterday. Connection seems good to the engine monitor. That's weird.
2. Dropping the cowl - the right exhaust is hanging lower than normal. Hmmm, that's weird. Push it back up.
3. Get settled under the engine and start to work on the starter solenoid. My plan was to actually take the big output wire and just temporarily bolt it onto the "input", or "hot" side of the solenoid. That way, I can just flip the master switch for a second to test how the starter spins the prop. Figured it was just a bit slower and a bunch safer than shorting it while sitting under the engine (mine's not very accessible while standing).
4. Whilst doing that, noticed that something was amiss - see picture below:



Turns out the bolt holding the ground wire to the engine case had wiggled out. It's the same bolt that holds the right exhaust hanger (aha!). The grounding wire wasn't making contact anymore, thus my sudden starting problem (aha!). But the starter did turn a little bit, right? Where was all that amperage going? Well, the oil temperature sensor died when I was trying to turn the engine. I'm thinking at least some of those amps went through the sensor and fried it. No other noticeable consequences to my AF-2500 engine monitor, though - I'll keep an eye.
Bolted the ground wire back on and she fired right up.
Mike Starkey - you're the big winner - it was the ground path after all.
Thanks for all the suggestions, and I think I'll probably get a spare starter solenoid because I'll bet it's only a matter of time, and not much.

Big lesson learned: Use your noodle and don't jump to conclusions. Every indication in the airplane was that the battery and charging system were just fine, so look elsewhere. I almost let the local A&Ps get a little too aggressive on my battery (they really don't know much about AGM batteries like the PC680) and they could've damaged it. They certainly weren't helping troubleshoot the real problem.

Now if only the weather would clear up, I'd be on my way...

[Mike S]

Jordan, glad you found the problem, and that it was cheap and easy to fix.

Thanks for the report back.