I am just about finished putting my 69 Coronet back together. Fired her up and testing everything out for the first time and most things are going OK, however some electrical issues that have me baffled.

First when I turn on the headlights the drivers side turn signals come on, not flashing just on.
Second the flashers only work with the ignition on.
Third my temp and fuel guages are not registering, has a new dash voltage regulator.

Any ideas of where to start looking would be appreciated.

Groundng. With new paint and connections all just plugged back together. The signal light thing sounds like the headlight may be trying to ground through that circuit.

On the guages you may just need to check those individual circuits, but I would start at the bulk head connector.

Just checked and redid the grounds above the headlights on the radiator support earlier, no change.
Going to go through the bulkhead connector now, though I cleaned those all up when putting everything together.

is it possible the headlights are grounding thru the turn signals
?---sometimes a bad turn signal switch on a later model car can cause odd symptoms too----i would work on the grounds---bob

For some reason the flashers started working, so one down.

Just rechecked all the grounds I could find and no change.

Looking a little better at the headlight issue, I found that its not the signals that are on. Only the indicator on the dash board and the fender mounted indicator are on. The drivers parking light itself isn't on when it should be, the passenger side is fine.

Back out to track down the gauges.

On the blinker indicators on with the headlites first make sure you have a good ground from the body to the eng and body to the battery. I have seen this many times over the years. The headlite is trying to find a ground back thru the blinker ind. Also a bad bulb can cause it as the park lites come on with the headlites and sometimes the park lite element in the turn signal/park bulb can contact the signal element and cause your problem. First take the front park lite bulbs one at a time and see if taking one out makes the ind go out. Should be the side that is lit on the dash. I have also had bad signal/park lite bulb sockets cause it as they can also loose their ground. Good luck , Ron

Update.
Got my lights all working, mostly just grounding issues and needed to swap out the dash dimmer switch.
Gas gauge is the sender, still need to replace that.

Had the temp and oil pressure (factory police??)gauges working well, then last time went to run it and the temp gauge doesnt register and the oil pressure pegs way past max. Could it be the regulator? Just put a new one in.......