Electrical Issue - where to start?

[1970Moparmann]

Hi all, have a weird grounding issue and not sure where to start.

During the day, with no driving lights on, passenger brake light is much dimmer than the drivers side.

At night, when I have the lights on, the gauge cluster hazard lights are constantly on and then the passenger brake light doesn't work.

What would be the recommend sequence of troubleshooting?

Thanks!

 

[Don Frelier]

Start with the bulb having the issue.
Examine the socket connection.
See if you can remove it, shine it up with a wire brush and reconnect.

 

[WileE]

Check grounds. Check bulbs. Source FSM electrical schematic, identify circuit in question, check circuit with multimeter.

 

[twecomm]

Certainly you may want to do as suggested above, but.. don't know about a 1970, but 4 years earlier in a 1966 model Charger & other Mopars of the era, brake lights and the turn signal (brighter filaments of the those dual filament bulbs) go thru the turn signal switch behind steering wheel. Just chased a no brake lights on L rear problem, R rear brake OK, all turn signals OK. it was defective turn signal switch.

 

[1970Moparmann]

Thanks guys!

 

[pnora]

Thanks guys!

During the day, with no driving lights on, passenger brake light is much dimmer than the drivers side.

Thats your clue. You have a ground or bulb issue at that area. Correct that first. Do not waste time and money on a turn signal switch at this time. What you have is a simple fix.

 

[twecomm]

May well be a lamp issue. Not recommending he run out to buy a turn signal switch, but think if I had an issue like his I would want to know that the brake lights and turn signal lights go thru that switch. Just more information relevant to troubleshoot his issue.