starter relay badly wired. Damage?

Lan Vinh Do · #1 03-13-2020, 03:58 PM

I just found on my rv-10 that the starter solenoid was weirdly wire. ( i was looking for a weak starter even with new battery )

I found that the key switch was wire to the I terminal. There was a diode from the I terminal to the S terminal and there was a wire from the S terminal to the ground.

The starter was working but just enough to start the engine. I think the I was energized and was passing current to the S by the diode and the S was grounded. So probably there was just barely enough current to close the relay.

I rewired it correctly.

Should i replace the relay that was wired like this since 2008 ( i am not the builder)

gasman · #2 03-13-2020, 06:56 PM

Quote:

Originally Posted by Lan Vinh Do

I just found on my rv-10 that the starter solenoid was weirdly wire. ( i was looking for a weak starter even with new battery )

I found that the key switch was wire to the I terminal. There was a diode from the I terminal to the S terminal and there was a wire from the S terminal to the ground.

The starter was working but just enough to start the engine. I think the I was energized and was passing current to the S by the diode and the S was grounded. So probably there was just barely enough current to close the relay.

I rewired it correctly.

Should i replace the relay that was wired like this since 2008 ( i am not the builder)

Did you get the plans with the aircraft? In the plans, you will find the correct way to wire the starter.

If you don't have the plans, contact Van's and purchase them... check their website.

Lan Vinh Do · #3 03-13-2020, 07:42 PM

I had the structural plan but not the electrical. Didn't find anything on starter relay.

I see instruction for the acs switch and one figure can be misleading for the installation of the diode. But i really think it wasn't wired the right way.

Here is a picture how it was wired. If anybody have a picture of their installation or the plan that show it, i will be happy to see it.

https://untilidie.home.blog/starter-relay/

rv8ch · #4 03-14-2020, 12:21 AM

If it works fine now, not sure you would need to replace it. If it fails at some point in the future, you'll be stuck on the ground - not a safety of flight issue.

On the other hand, a new one is $35.

https://bandc.com/product/intermitte...ter-contactor/

Just please be careful to not accidentally activate it and spin the prop with you or someone else in the path. (I know you know this, but I couldn't help myself.)

lr172 · #5 03-14-2020, 08:07 AM

If the rewiring did not improve starter performance, I suggest you replace the solenoid. They are not very sophisticated inside and wear over time can cause a poor connection with low starting current. If it cranks like a monster now, there shoud be no need to replace it.

I Just pulled the solenoid on my 6, due to weak cranking. PUlled it apart and it was obvious that I was getting a poor connection inside. New solenoid addressed the issue.

Larry

JonJay · #6 03-14-2020, 11:46 AM

They way it was wired before shouldn?t cause a starter issue. The diode was rendered useless and provided no protections. My guess is rewiring didn?t improve how the starter spins?
I agree with others. There is something else wrong.

Lan Vinh Do · #7 03-15-2020, 08:22 AM

You were right. I replace the relay and not much improvement. It turn the prop ( before it was stopping at the first compression and i had to turn the key again. After the second attempt it was turning) Now it doesn't stop but it's not much faster.

I change the odyssey 2 years ago for the same reason. Since new, i wasn't able to have a open voltage more than 12.5 or 12.6. So by reading probably more a battery problem ( 50% charged at 12.5v) than a wiring issue. I probably had a bad battery. New one is order with an approved odyssey charger. After i remove the old one, i will try to rejuvenate it as recommended but it look like it was already sulfonated when i received it 2 years ago.