---------------------------------------------------------- TeamGrumman-List Digest Archive --- Total Messages Posted Sun 02/26/06: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:49 PM - P-leads and grounding of shields (Gil Alexander) 2. 09:08 PM - Re: P-leads and grounding of shields (TeamGrumman@aol.com) 3. 09:34 PM - Re: P-leads and grounding of shields (Gil Alexander) ________________________________ Message 1 _____________________________________ Time: 03:49:17 PM PST US From: Gil Alexander Subject: TeamGrumman-List: P-leads and grounding of shields --> TeamGrumman-List message posted by: Gil Alexander posted on the other list too.... I'm installing a new Horizon electronic tach. and replacing my p--leads at the same time, since the switch is out, and the cowling off for the Mitchell instrument installation - the old "while we are it" - and the magneto end does look ratty... However, I can't find the correct wiring for the shields of the p-leads at the ignition switch. My p-leads have been changed in the past (actually had a log book entry...: ) so I no longer know what the correct original configuration should be... Do the p-lead shields connect to the ground terminal at the ignition switch? This would seem to be a good way of connecting, and no extra ground would be needed at the switch. However, Gary's schematic shows a separate ground wire at the switch (going to the airframe - called 51JA3), and NO shield connections at the switch.... this would also seem correct. But, if I attach the P-leads shield to the ignition switch ground, and also take it to the airframe, I have made a large ground loop in a noisy circuit - I think. This does not seem correct, but that is how the present switch is wired. Does anyone know the correct wiring of shields at the ignition switch? ...thanks gil in Tucson 77 Tiger ________________________________ Message 2 _____________________________________ Time: 09:08:34 PM PST US From: TeamGrumman@aol.com Subject: Re: TeamGrumman-List: P-leads and grounding of shields --> TeamGrumman-List message posted by: TeamGrumman@aol.com the shield on the P-lead doesn't ground at the magneto switch. ________________________________ Message 3 _____________________________________ Time: 09:34:19 PM PST US From: Gil Alexander Subject: Re: TeamGrumman-List: P-leads and grounding of shields --> TeamGrumman-List message posted by: Gil Alexander Thanks Gary... that makes sense from a "no ground loop" point of view. And it makes the wiring easier.... less shields to dress on the wire. I presume 18 gauge shielded wire from Aircraft Spruce is OK.... MIL-C-27500 ....thanks gil in Tucson At 10:07 PM 2/26/2006, you wrote: >--> TeamGrumman-List message posted by: TeamGrumman@aol.com > >the shield on the P-lead doesn't ground at the magneto switch. > >