Attention: TDR Forum Junkies 
7 way connection component inspection or just some nasty weather ramblings and keyboard time.
Over on an Airstream forum 7 way connections are fairly frequent "it don't work" item in part I think due to the OE plug they use. I did this inspection to try to look behind the curtain on this mysterious connection.
I have a collection of new plugs and receptacles and put them on the bench to examine the connection system. Plugs included the original Bargman "V" style, flat blade plugs from Pollak believed to be a 12-702, Hopkins 48510 and an off-brand generic. The Bargman was in poor condition and would not even plug in to any receptacle. The other three plugs were examined and one measurable observation was readily apparent. The distance between the flat blades, inside to inside. See Ref. 1. The Hopkins 48510 measured .910" a second 48510 was measured at .915” between two opposing flats. The Pollak .980" and generic .990".
Each was inserted by hand plug only to receptacle only, no housings to interfere with the fitment of the contacts to blades to feel the force to insert and disconnect. Then an adjustable wrench was set to the measured gap and then test fitted on the receptacle. The .910" gap compressed the "V" and made a firm purchase on it, even holding it firmly for the picture. See Ref. 2. The same connection test was made with a .990" gap. It would not hold the receptacle and it made contact on a slant, see Ref. 3. It noticeably took more pull to separate the tighter .910" than the .990" from the receptacle.
My observation is that the tighter plug blade compressed the receptacle plug V and visually makes a larger surface for the electrical connection.
The next observation was inserting the various assembled plugs into my 2005 Dodge Ram original receptacle which was made by Pollak and feeling the apparent fitment force and checking the depth of insertion. The fitment feel is subjective, not measured. The .910" required more force to insert and remove. The depth of insertion is an easy one that you can check with a Sharpie or a pencil. Place the plug into the receptacle stopping at initial contact but do not fully insert, mark the side of the plug relative to the receptacle. Now insert and mark the plug again. Remove the plug and observe the insertion depth. Is it at least 3/8"? See Ref. 4.
I have had the Pollak style metal housing plug on my Airstream for several years and it has worked every time. I likely will be looking at installing the Hopkins 48510. It does have an unusual internal frame that the wires must go around to make the connection.
These are observations from an owner not based on any standards or manufacturers data. Check your connection terminals and review for repairs. You guys are pretty hands on so this might be a yawn but here it is.
Just an FYI.
Gary
Over on an Airstream forum 7 way connections are fairly frequent "it don't work" item in part I think due to the OE plug they use. I did this inspection to try to look behind the curtain on this mysterious connection.
I have a collection of new plugs and receptacles and put them on the bench to examine the connection system. Plugs included the original Bargman "V" style, flat blade plugs from Pollak believed to be a 12-702, Hopkins 48510 and an off-brand generic. The Bargman was in poor condition and would not even plug in to any receptacle. The other three plugs were examined and one measurable observation was readily apparent. The distance between the flat blades, inside to inside. See Ref. 1. The Hopkins 48510 measured .910" a second 48510 was measured at .915” between two opposing flats. The Pollak .980" and generic .990".
Each was inserted by hand plug only to receptacle only, no housings to interfere with the fitment of the contacts to blades to feel the force to insert and disconnect. Then an adjustable wrench was set to the measured gap and then test fitted on the receptacle. The .910" gap compressed the "V" and made a firm purchase on it, even holding it firmly for the picture. See Ref. 2. The same connection test was made with a .990" gap. It would not hold the receptacle and it made contact on a slant, see Ref. 3. It noticeably took more pull to separate the tighter .910" than the .990" from the receptacle.
My observation is that the tighter plug blade compressed the receptacle plug V and visually makes a larger surface for the electrical connection.
The next observation was inserting the various assembled plugs into my 2005 Dodge Ram original receptacle which was made by Pollak and feeling the apparent fitment force and checking the depth of insertion. The fitment feel is subjective, not measured. The .910" required more force to insert and remove. The depth of insertion is an easy one that you can check with a Sharpie or a pencil. Place the plug into the receptacle stopping at initial contact but do not fully insert, mark the side of the plug relative to the receptacle. Now insert and mark the plug again. Remove the plug and observe the insertion depth. Is it at least 3/8"? See Ref. 4.
I have had the Pollak style metal housing plug on my Airstream for several years and it has worked every time. I likely will be looking at installing the Hopkins 48510. It does have an unusual internal frame that the wires must go around to make the connection.
These are observations from an owner not based on any standards or manufacturers data. Check your connection terminals and review for repairs. You guys are pretty hands on so this might be a yawn but here it is.
Just an FYI.
Gary
