rally dash headaches

[jdscofield]

Earlier this week, I posted about swapping out gauges in a rally dash for a 74 charger.  This was due to discovering my gauges no longer worked and my battery was dead after some heavy rains.  Before the rains, I installed a new cigar lighter because the old one no longer worked.  The last time I did this was 20 years ago on my first 74 charger.  installed the lighter.....headlights stopped working.  So this time, everything seemed to work fine, except the new lighter still did not work.  Then the rain came, to which I discovered my windshield leaks.  So the rains stop, I go to start the charger, battery is dead, charge the battery, start the car, and realize my temp and oil pressure gauges don't work.  the only gauge that does work is the volt meter.  Last night, it dawned on me that I didn't notice the dash lights come on.  So I check and sure enough, they do not work, nor do my parking lights.  Headlights work, turn signals work, high beam indicator works, and brake lights work.  My thought is the voltage regulator went bad and shot 12v to the 6v gauges.  However, i'm stumped about the dash lights and parking lights (which really irritates me because I had them working fine).  Is the light switch tied into that circuit board behind the dash to which the voltage regulator is connected, or could it just be coincidence and be a faulty light switch?  What does that circuit board actually control?  could I just remove the old gauges, and wire in new gauges directly?  Any advice will be helpful.  the wiring schematic in my Haynes blows.

[daytona71]

Factory wiring diagram for your car can be found at the following:  http://www.mymopar.com/index.php?pid=28

[jdscofield]

Thanks

[Pete in NH]

Hi,

The dash board printed circuit board contains mostly the gauge wiring and gauge voltage regulator. It also provides the wiring paths for the dash lights. I would suspect something happened in the process of installling the new lighter if everything worked normally before then. You mentioned the battery going dead. Has that happened before? One thing to check out could be the bulkhead connectors. They are a known trouble spot. With the windshield leaks you mentioned , if they are on the driver's side the bulkhead connectors may have been soaked and corrosion has set in. It might be worth unplugging the connectors and see what they look like.

[Nacho-RT74]

Factory wiring diagram for your car can be found at the following:  http://www.mymopar.com/index.php?pid=28

actually incorrect for 74s and some other years... but pretty much will work for dash issues