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  #16  
Old 10-20-2012, 07:25 PM
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I still would monitor that sender with ohms readings. A meter is less than five dollars or substitute the sender even with a used one.

You know something is erratic or intermittent if you wish so some simple hooking and unhooking tests are not conclusive. In the electrical gauge area for oil presure readings the senders are usually the most common issue. You kind of have to pay attention to them first. This means proving their status one way or another for sure before moving on.

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  #17  
Old 10-20-2012, 11:20 PM
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Quote:
Originally Posted by barry12345 View Post
I still would monitor that sender with ohms readings. A meter is less than five dollars or substitute the sender even with a used one.

You know something is erratic or intermittent if you wish so some simple hooking and unhooking tests are not conclusive. In the electrical gauge area for oil presure readings the senders are usually the most common issue. You kind of have to pay attention to them first. This means proving their status one way or another for sure before moving on.
Before startup, sender shows about 40 ohms. Once started, sender immediately drops to open line (infinity ohms). On shutdown the sender ramps 'down' quickly to about 100 ohms and then slowly tapers off back to the previous 40 ohms. That's the cycle over two checks. Of course, both of these checks could have missed the intermittent problem. I traced the lead wire back through the connection block on the wheel well. No shorts or odd resistance readings anywhere there.

Running resistance check all the way back the other way (through sender wire to gauge then back to ground) shows a stable 40-50 ohms no matter what else is happening.


Next step, I guess, is to pull the cluster. Not sure what I am looking for.
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  #18  
Old 11-12-2012, 01:06 AM
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Join Date: Mar 2011
Location: Victoria Canada
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It was the gauge at the cluster

Ok, it was the gauge. I had a spare cluster laying about so I swapped that in. This led to a host of other problems (no instrument lights, faulty fuel gauge etc) but the oil pressure gauge worked fine for about a week.

I took the original cluster, pulled the left hand gauge set, cleaned up all the pins and put it back. Nothing obvious out of whack, but the cleaned up gauge set has worked flawlessly for another week and I consider this problem solved.

A simple fix and certainly less messy than swapping out the sender.

Thanks to all for the help.

Quote:
Originally Posted by birkhoff View Post
Before startup, sender shows about 40 ohms. Once started, sender immediately drops to open line (infinity ohms). On shutdown the sender ramps 'down' quickly to about 100 ohms and then slowly tapers off back to the previous 40 ohms. That's the cycle over two checks. Of course, both of these checks could have missed the intermittent problem. I traced the lead wire back through the connection block on the wheel well. No shorts or odd resistance readings anywhere there.

Running resistance check all the way back the other way (through sender wire to gauge then back to ground) shows a stable 40-50 ohms no matter what else is happening.


Next step, I guess, is to pull the cluster. Not sure what I am looking for.
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  #19  
Old 11-12-2012, 02:09 AM
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Yes

Quote:
Originally Posted by birkhoff View Post
Ok, it was the gauge. I had a spare cluster laying about so I swapped that in. This led to a host of other problems (no instrument lights, faulty fuel gauge etc) but the oil pressure gauge worked fine for about a week.

I took the original cluster, pulled the left hand gauge set, cleaned up all the pins and put it back. Nothing obvious out of whack, but the cleaned up gauge set has worked flawlessly for another week and I consider this problem solved.

A simple fix and certainly less messy than swapping out the sender.

Thanks to all for the help.
Corrosion strikes again.
Glad it was so simple...


.

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