Fuel and temp guage lights went out and now they sûddenly work again.

Author Topic: Fuel and temp guage lights went out and now they sûddenly work again.  (Read 1152 times)

Offline Tonefiend

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So last week I install a MSD ignition Digital 6A.  I bypass the ballast resistor and tie those three wires together. Two blues and one gray wire.

 All seems fine except for the fact that my alternator gauge is fluctuating and the fuel and temperature gauge lights went out. tonight driving home those lights suddenly came back on. I originally thought I blew the bulbs out when I bypass the ballast resistor.

 Also the car intermittently doesn't start in park. I've had problems with the neutral safety switch connector not staying plugged in but I am Not sure if that is the case here.

 Any ideas what would cause the two left small gauge lights to go out? It is the actual lights in the gauges and not the ones in the light bar above.




Offline DocMel

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Re: Fuel and temp guage lights went out and now they sûddenly work again.
« Reply #1 on: September 10, 2013 - 09:37:21 AM »
Man, I hate those kind of electrical probs:  You do some work, and all of a sudden, theres a new prob

I have the same MSD in my 71 Cuda:   I can only say as far as the lights went out, then back on on your fuel and temp face, I dont believe the issue is related with your MSD installation.

There is a light bulb that inserts into the back of the dash cluster that houses your fuel, temp, oil pressure and amp gauge.  You might just have a bad bulb to socket connection, maybe slightly corroded, causing an intermittent operation.  That bulb/socket is a PIA to get to.  You MIGHT be able to reach behind the dash, (I dont recommend this even if you could reach back there.  You could unintentionally pull off some wires back there), and pull it out, but if you cant,  the whole dash instrument panel needs to come out:  Not a tough job, but a little time consuming.  The only saving grace here is if you have to remove the dash, you can take the op to also clean/polish the clear plastic, maybe redo the faux woodgrain paneling, etc :   A word of advice:  If you go this route and remove the dash cluster, TAKE YOUR TIME. 

Lower the steering column by removing the four bolts that house the column fasica cover under the dash.  Then use a deep socket and loosen ,almost all the way, but do NOT remove, the two nuts (one on each side) that holds the steering column up.  As you loosen the nuts, you will see the column start to slowly lower:  It will give you enough room to remove the dash without scratching the hell out of the steering column.  Its also almost impossible to remove the dash without the extra room as well

Make note of what screws went where.  There will be about 20 or so screws total.  Be aware, some are hard to see, some are recessed.  Some are on the far left (facing the inner door when closed) and far right of the dash, seeming to not even relate to removing the dash:  Take your time, and don't force anything.   Have a small flashlite to look in the recessed holes or dark areas.   You will need a stubby phillips  screw driver to get to some of the screws

When you remove the dash, take care of the far left panel that houses the dimmer, wiper and drive light switches.  If you pull the switch connectors off the back, understand they are 40 or so years old, and can crack or break very easily:  I would NOT use an electric screwdriver, ESPECIALLY when reinstalling.  All the dash plastic is very brittle

When you are done inspecting, put the gauge cluster back in place, but before you screw it in or go any further, be sure everything works.  BE VERY careful of the amp meter lugs on the back of the dash cluster:  Its 12v hot, so you dont want to accidentally ground it.   

Offline Tonefiend

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Re: Fuel and temp guage lights went out and now they sûddenly work again.
« Reply #2 on: September 10, 2013 - 08:18:00 PM »
Thanks DocMel that's actually quite helpful as I need to pull the speedo and get it fixed.  My gauge lenses are also quite dull and I need to polish them up and fix the wiper switch, replace the heater control cable, speedo cable.... 

Mabe I should bypass the alternator guage while I am there as well.  I'd like to install some other gauges in there and make face plates that match the old Mopar ones.  I am familiar with silk screening and fabrication so I could pull it off. 

Also my horn no longer works.  Who knows when that went out.  I found it strange only two lights went out.  I figured I crossed some wires and blew them out.  But when they came back on it became even stranger my theory is all 4 would be on the same circuit so all 4 go out or none.   This car is full of all sorts of electrical gremlins I have been chasing down.

Offline Tonefiend

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Re: Fuel and temp guage lights went out and now they sûddenly work again.
« Reply #3 on: September 11, 2013 - 05:35:16 PM »
Last night I'm driving home and the 2 gauge lights go out again.   I remembered some advise I received in another thread to smack it.  So I pounded on the dash and that worked! The lights came back on and work fine.  I was just a coincidence they decided to go out at the exact moment I installed the MSD.  Isn't that how it usually works?   ::)  Problem solved thanks CC.Com!

\
Ha!  Well obviously an excursion into the dash is in order to straighten out the multitude of problems.  The above info will mos def come in handy.   


Offline dodj

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Re: Fuel and temp guage lights went out and now they sûddenly work again.
« Reply #4 on: September 11, 2013 - 06:39:50 PM »
There are no lights for your gauges mounted from behind the cluster. It is all indirect lighting from above. (unless you have after market gauges?). The screws that mount the light bar provide the ground for the light bar. If pounding on the dash gave you your lights back, perhaps those screws are loose. Another likely culprit is the dimmer switch. They are notorious for failing.  :2cents:
Scott
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2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline DocMel

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Re: Fuel and temp guage lights went out and now they sûddenly work again.
« Reply #5 on: September 11, 2013 - 06:59:26 PM »
???  There are 2 bulbs that plug directly into the back of the gauge cluster

One goes into the back/bottom of the cluster that has the fuel, temp, oil pres and amp gauges.  If it isnt there to light the face of those gauges, it sure does the job regardless

Another goes into the back, I cant remember, with the speedo or tach cluster:  That one could be the high/low beam indicator


And yes, there are the 4 or 5 green tinted lights that shine on the face of all gauges

Offline Chryco Psycho

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Re: Fuel and temp guage lights went out and now they sûddenly work again.
« Reply #6 on: September 11, 2013 - 07:53:20 PM »
grounding problem with the lights , gauges could be a loose connection

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