Author Topic: Instrument posts conductive gel?  (Read 2507 times)

Offline fiddler

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Instrument posts conductive gel?
« on: May 03, 2023, 07:03:51 PM »
I have a 1974 chevy C10 stepside.  The instrument panel appears to be from 1976 or later vintage.  The gas gauge and voltmeter are now making intermittent contact with the posts.  It took awhile but I was finally able to catch the meter showing battery level when the battery was actually measuring 13 volts on my dvm.  A few taps on the area around the meter brought it back.  So I will open the panel up again and reseat the voltmeter and gas gauge, but...is there some kind of conductive gel I could put on the posts to get a more secure contact?  Anybody have some ideas on this?  Sharing of any experience with this failure mode would be appreciated.  Thanks much in advance....
Ricky

Offline JohnnyPopper

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Re: Instrument posts conductive gel?
« Reply #1 on: May 03, 2023, 08:25:19 PM »
DeoxIT D5
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline bd

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Re: Instrument posts conductive gel?
« Reply #2 on: May 03, 2023, 11:06:58 PM »
Several issues can occur.  Oxidation is one of them.  Weak contact pressure is another.

Recommendations:
  • Remove the offending gauges and the corresponding gauge contact clips...

                       

  • Using a soft #2 pencil eraser or crocus cloth, GENTLY BURNISH the copper foils of the PCB where the gauge clips make contact with the PCB.  Remove all of the copper oxide coating until bright.  Be very attentive and careful that you don't peel the foil free from the plastic substrate - an easy mistake to make.

  • Similarly, burnish the surfaces of the clips that contact the copper foil and the gauge pins, until shiny.

  • Using a pair of needle nose pliers, slightly bend the dimpled flags to increase contact pressure against the PCB.  Don't overdo it.

  • Next, use the needle nose pliers to bend the clips' spring contacts that pinch the gauge pins and narrow the gap to increase contact pressure against the gauge pins.  I generally decrease the gap just to zero.  There will be a noticeable increase in insertion pressure required to reinstall the gauges.  But again, don't overdo it or you will risk struggling to reinstall the gauges without dislodging the clips out the back of the cluster.

  • To slow the recurrence of oxidation, you can sparingly apply a light film of dielectric grease or Deoxit D5 between the clips and the PCB.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
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Offline VileZambonie

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Re: Instrument posts conductive gel?
« Reply #3 on: May 04, 2023, 05:28:59 PM »
You can solder them as well once you clean all of those connections but you need a good soldering iron. Milwaukee m12 soldering iron is a MUST have for all btw. Never mess around again.
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