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  #1  
Old 12-31-2008, 03:02 PM
prkaye prkaye is offline
 
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Default 2 ground terminals to same bolt?

Is there any reason why this is a no-no? I have ground straps from battery and from engine block going to the same bolt on my ground block... see photo below.
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  #2  
Old 12-31-2008, 03:07 PM
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Mel Mel is online now
 
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Default Not a problem.

It is acceptable to have up to 3 wires per ground post.
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  #3  
Old 12-31-2008, 03:26 PM
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N941WR N941WR is offline
 
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Default

Phil,

I did the same as you but my tech inspector wanted to see a secondary ground from my engine to someplace on the engine mount or fuselage. This in case the primary one fails.

We figured the SS lines for the oil and fuel pressure will work just fine.
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  #4  
Old 12-31-2008, 04:52 PM
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Default Back-up Engine Ground

For some reason, I forgot to install the ground cable and was working with the starter. The engine of course would barely turn over, but somehow I noticed the SS oil pressure line got warm. A check with my cheapo voltmeter showed no zero ohms from the engine case to the battery... so I was stumped for a moment.

Looks like the SS oil pressure line will work as a back-up ground cable, but may have some current limits or resistance issues. I don't know what the limitations are, or if they are even limitations at all. I would be interested to know if anyone has looked into this.
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  #5  
Old 12-31-2008, 07:01 PM
PCHunt PCHunt is offline
 
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Location: San Diego, CA
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Thumbs down Bad Idea

Quote:
Originally Posted by Jonathan Cude View Post
........ Looks like the SS oil pressure line will work as a back-up ground cable, but may have some current limits or resistance issues. I don't know what the limitations are, or if they are even limitations at all. I would be interested to know if anyone has looked into this.
You NEVER want a fluid carrying line to be a current carrier! Can you imagine a fuel line under pressure with hi-amp current running through it, then it breaks with a spark...............! Yikes!
Thus the reason for a backup real ground.
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  #6  
Old 01-01-2009, 12:10 AM
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N941WR N941WR is offline
 
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Default

Quote:
Originally Posted by Jonathan Cude View Post
For some reason, I forgot to install the ground cable and was working with the starter. The engine of course would barely turn over, but somehow I noticed the SS oil pressure line got warm. A check with my cheapo voltmeter showed no zero ohms from the engine case to the battery... so I was stumped for a moment.

Looks like the SS oil pressure line will work as a back-up ground cable, but may have some current limits or resistance issues. I don't know what the limitations are, or if they are even limitations at all. I would be interested to know if anyone has looked into this.
This is only a backup and will help get you home, you really don't want to try and start your engine with this.

As I said, they are good for a backup path only.
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  #7  
Old 01-01-2009, 07:47 AM
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L.Adamson L.Adamson is offline
 
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Default

Quote:
Originally Posted by N941WR View Post
This is only a backup and will help get you home, you really don't want to try and start your engine with this.

As I said, they are good for a backup path only.
I have a heavy braided cable from the engine to the firewall, and don't figure it will break or fall off before an engine mount does. But I'll keep it in mind to check once and a while. At least I can see it through the oil dip stick door opening.

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