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- Dec 21, 2017
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I've been chasing starting issues for about 6 months now, and it just got worse. Here are the details:
'73 PA-28
Concord RG-35A Battery (2 years old)
Original master and starter solenoids (probably)
Bogert STC copper cables and battery box mod (just installed)
Skytec starter (1 year old)
After installing the copper cables I tried to start it, and it behaved just like it always has. The first time it stalled out on the compression stroke. Another try put it past the compression stroke and it started.
Tonight I went out to the hangar to hunt for voltage drops. The first couple of times I cranked, it made a weak attempt at turning, but it was never able to make it past the compression stroke. After that the solenoid would just click with no rotation at all or any other noise. I limited all my starting attempts to less than 3 seconds and gave at least 5 minutes between attempts.
Here are the results of my voltage drop testing:
Battery to ground: 8.9v
Starter solenoid input to ground: 8.5v
Starter solenoid output to ground: 8.4v
I couldn't get a reading at the starter itself because I didn't want to drop the lower cowl by myself.
I'm tempted to just replace the battery since 8.9v at the battery is unacceptable. However, I'm concerned that the real problem is in the starter since it's not moving at all. I would expect it to at least make a feeble attempt on 8.4v. Is that incorrect?
Also, on the first couple of tries I faintly smelled rotten eggs coming from the battery, which I know is hydrogen sulfide. That seemed super weird since that's supposed to be an issue with overcharging, not a discharge issue. Any ideas here?
'73 PA-28
Concord RG-35A Battery (2 years old)
Original master and starter solenoids (probably)
Bogert STC copper cables and battery box mod (just installed)
Skytec starter (1 year old)
After installing the copper cables I tried to start it, and it behaved just like it always has. The first time it stalled out on the compression stroke. Another try put it past the compression stroke and it started.
Tonight I went out to the hangar to hunt for voltage drops. The first couple of times I cranked, it made a weak attempt at turning, but it was never able to make it past the compression stroke. After that the solenoid would just click with no rotation at all or any other noise. I limited all my starting attempts to less than 3 seconds and gave at least 5 minutes between attempts.
Here are the results of my voltage drop testing:
Battery to ground: 8.9v
Starter solenoid input to ground: 8.5v
Starter solenoid output to ground: 8.4v
I couldn't get a reading at the starter itself because I didn't want to drop the lower cowl by myself.
I'm tempted to just replace the battery since 8.9v at the battery is unacceptable. However, I'm concerned that the real problem is in the starter since it's not moving at all. I would expect it to at least make a feeble attempt on 8.4v. Is that incorrect?
Also, on the first couple of tries I faintly smelled rotten eggs coming from the battery, which I know is hydrogen sulfide. That seemed super weird since that's supposed to be an issue with overcharging, not a discharge issue. Any ideas here?
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