1968 Newport tail light brake light issue

Electrical & Ignition

  1. Teek

    Teek New Member

    Likes Received:
    Jul 25, 2019
    Hi I am having an issue diagnosing why I have no brake light or signal light on the back right side ? signal light works on right front side.And I have no power on my fuel gauge wire I ran a new wire from the back of the fuel gauge to the fuel sending unit and still no power ? any help would be great thank you
  2. rkrochen

    rkrochen Active Member

    Likes Received:
    Jun 29, 2015
    Teulon, Manitoba
    Possibilities include bad ground at the bulb, bad bulb, bad connection at the bulkhead for the rear harness or even turn signal switch. You need to get a FSM to trace the wiring. Start with the simple things.
    The fuel gauge will depend on the year and model of the car.
  3. jct

    jct Senior Member FCBO Gold Member

    Likes Received:
    Jun 11, 2015
    Bet his instrument panel voltage regulator bit the dust
  4. Davea Lux

    Davea Lux Senior Member FCBO Gold Member

    Likes Received:
    Mar 27, 2017
    Cornelius Or
    Try using a jumper to by pass the brake light switch to see if you then have brake lights. If you still do not have brake lights, as noted check the ground to the rear taillight assemblies, check to be sure the 4 way flasher switch is properly parked. The brake lights are routed thru the turn signal switch, so of the turn signal switch is bad that often also kills the brake lights. Be sure to check the fuse for the brake lights as well.

    Most likely, the problem with the gas gauge is the cluster voltage regulator. Disconnect the wire from the tank sending unit and use a test light to see if you are getting power to the lead. If it is getting power, the test light should blink on and off as the cluster regulator cycles. If you are not getting power, the regulator is probably bad. The regulator on most late '60's mopar plugs into the back of the instrument cluster and can be a real pain to get at. Test the small fuse to the instruments to be sure it is good before going after the cluster regulator. If you got a blinking test light on the previous test, then the tank unit has failed and you will need either a new unit or a new float for the unit depending on what has failed.

  5. cbarge

    cbarge Senior Member FCBO Gold Member

    Likes Received:
    Nov 22, 2010
    Kingston Ontario Eh?
    Did you change the bulb yet?
    Remember body is ground on our cars..
    Tail light;
    Ground a jumper wire from anywhere in the trunk to the base of the light socket. Should light up.
    Fuel gauge;
    With key on ACC (backwards to run radio) use a test light at the plug at the tank wire. make sure it has good ground on the chassis somewhere.
    Test light should "blink" and be dim (5 volts) No test light no power. Run an extra ground wire from the gas line at sending unit and ground it to good metal anywhere underneath. Check gauge to see if it works.
    Check rear harness plug behind driver's kick panel. Clean connections and test brown wire for power on the light circuit and blue wire for gas gauge circuit. No power at blue wire means the 5 volt limiter for the gas gauge is fried.
    no power at plug on brown wire you will have to dig deeper.
    Give me an update once at this point and can go further if needed.
    Hope this helps..
  6. Castle

    Castle Member

    Likes Received:
    Jul 12, 2018
    Rochester NY
    Pull the lights out, use a test light to make the ground to the bulb housing and see if the bulb lights when the break is applied.... go from there.... most likely it’s a ground issue.