I did have the same problem...the bulb was not in good contact with the
copper part of the blue foil. I use a conductive paste, put a drop at the
contact area of the bulb, let it dry and it works again.
https://www.amazon.com/Silver-Conductive-Electronics-Repair-omyBigDeal/dp/B00WF81X92

Some people use a conductive tape, I tried that too, but I recommend the
paste because the tape doesn't adhere well. It worked once but if you
remove the bulb the tape came with it.
https://www.amazon.com/Zehhe-Copper-Foil-Double-Sided-Conductive/dp/B01MR5DSCM/ref=sr_1_22?dchild=1&keywords=copper+conductive+paste&qid=1631721124&sr=8-22

On Wed, Sep 15, 2021 at 7:41 AM Bruce Todd <beeceetee@gmail.com> wrote:

> OK - got 2 of the Leds working - for whatever reason I just could not get
> the 3rd (the bulb housed over the tach) one to work or even flicker.  I
> think I'll try again another time.  Put the old style bulb back in for the
> time being and all is good.
>
> Bruce
>
>
>
> On Tue, Sep 14, 2021 at 11:05 AM <christopher@t3technique.com> wrote:
>
> > Bruce - I'm glad you like the new gauge faces. Ken is definitely correct
> > about the polarity of the LED lamps (thanks for adding that, Ken). Also,
> > the foil can get worn in the area where the lamps make contact.
> Sometimes a
> > little finagling is necessary to get them to make proper contact.
> >
> >
> >
> > -----Original Message-----
> > From: Vanagon Mailing List <vanagon@gerry.vanagon.com> On Behalf Of
> Bruce
> > Todd
> > Sent: Tuesday, September 14, 2021 10:08 AM
> > To: vanagon@GERRY.VANAGON.COM
> > Subject: Re: Plasma gauge set
> >
> > Thanks Kenneth - I'll give it another go.   I get a little nervous when
> it
> > comes to continually touching the foil and wonder how many bulb twists I
> > have left.
> >
> > Bruce
> >
> > On Tue, Sep 14, 2021 at 10:03 AM kenneth wilford <kenwilfy@gmail.com>
> > wrote:
> >
> > > Bruce, LED bulbs must be installed a certain way to work.  In other
> > > words they need to be installed so that plus matches plug and minus
> > > matches minus.  If they aren't they won't work.  Normal bulbs don't
> > > have this issue.  So if you can't get LED instrument lights to work,
> > > turn them around and they should work.
> > >
> > > Ken
> > >
> > > On Tue, Sep 14, 2021 at 10:16 AM Bruce Todd <beeceetee@gmail.com>
> wrote:
> > >
> > >> Just wanted to report I spent the weekend ploddingly installing a
> > >> plasma gauge set and really like the results.  The instructions were
> > >> pretty straight forward and luckily everything came apart easily and
> > >> I didn't further depreciate the brittle plastic gauge and instrument
> > >> housing or the blue plastic ribbon.
> > >>
> > >> The only thing that I couldn't get working were the replacement LED
> > >> bulbs
> > >> -
> > >> so I kept the old style  bulbs in place instead.  The plasma gauges
> > >> are backlit so it doesn't really matter.
> > >>
> > >> This is a really nice upgrade.
> > >>
> > >> https://t3technique.com/electrical/plasma-gauge-set/
> > >>
> > >> Bruce
> > >>
> > >
> >
> >
>