Announcement

Collapse
No announcement yet.

Headlight voltage issues

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Headlight voltage issues

    I'm trying to get the parts car I recently acquired road worthy and the headlights don't work. High beams and low beams. Literally everything else works. Turn signals, tail, brake lights, corner lights, interior etc.

    I installed a new 9006 low beam to no avail.

    I have to disconnect the battery or it drains it.

    With the headlight switch off and the ignition off I have just under 2 volts to the driver side low beam headlight. And under a volt to the passenger side low beam headlight. The high beams have no power. Turning the headlight switch on yields the same results.

    I have installed a repaired main relay, removed A/C and power steering, third brake light, condenser fan, factory fog lights, ignition lock assembly (just using ignition switch) and other non-electrical items. Nothing was difficult or troubling. All grounds are good. I installed a new battery as the car came without one.

    I ordered a replacement turn signal/ headlight switch. That's all I can think of so far however I'm not confident that it will solve the issue.

    Any ideas or advice is greatly appreciated.
    Last edited by H311RA151N; 05-24-2020, 06:46 AM.





    #2
    Do you get 12V at the fuse box fuse? (fuse #37)

    You specifically tested the ground C, right side of engine compartment? And also under the fuse box (under the hood)?

    Have you done a wire resistance test on the headlight wire from fuse box to end of wire?

    (not sure if dimmer relay can do this or not.... )

    Comment


      #3
      I do not get 12v to the fuse box. Not fuse 37 or 38. 1.9ish volts to 37 and 0.08ish volts to 38 regardless of headlight switch position or ignition switch position.

      Grounds I've checked: Battery negative to fender well, thermostat housing, valve cover and interior fuse panel 10mm bolt.

      I haven't yet but will check the ground by the condenser fan relays, under the underhood fuse box, and I think there is another by the air filter box according to the FSM.

      I have not done a resistance test from fuse box end of wires to head light bulb end of wires. But I will when i get my long probe leads from work today.

      I have a complete spare underhood fuse box and swapped both the headlight relay and dimmer relay to no avail.

      Thank you for the reply!




      Comment


        #4
        Based upon the wiring diagram, Fuse #37 is for the Left Headlight, Fuse #38 for the Right Headlight, both tie back to Ground C (Right side of engine compartment), and the Dimmer Relay.

        Outside of that, it looks like the Dimmer Relay feeds into the combination switch / vice versa, which ties into Ground S (Below Left Side of Dash). Would check/clean the ground to there as well. Otherwise, next thing might be the actual combination switch itself?

        The (Haynes) wiring guide I uploaded years ago: http://www.cb7tuner.com/vbb/showthread.php?t=184559
        PT3/6 Development Thread | My 1991 LX Coupe | DIY: 90-93 Tcu Fix

        Comment


          #5
          Check the ground under the fuse box passenger side and also. Not sure if that's the headlights wire ground or not though...

          Comment


            #6
            Originally posted by cloudasc View Post
            Based upon the wiring diagram, Fuse #37 is for the Left Headlight, Fuse #38 for the Right Headlight, both tie back to Ground C (Right side of engine compartment), and the Dimmer Relay.

            Outside of that, it looks like the Dimmer Relay feeds into the combination switch / vice versa, which ties into Ground S (Below Left Side of Dash). Would check/clean the ground to there as well. Otherwise, next thing might be the actual combination switch itself?

            The (Haynes) wiring guide I uploaded years ago: http://www.cb7tuner.com/vbb/showthread.php?t=184559
            I appreciate the link! That actually covers the grounds a bit better than the FSM which is what I was going by.

            Checking and cleaning grounds C and S more thoroughly today. Changed dimmer relay but will check socket/ connections. I ordered a used combination switch.

            Thanks for the reply!

            Originally posted by Raf99 View Post
            Check the ground under the fuse box passenger side and also. Not sure if that's the headlights wire ground or not though...

            Will do that again in further detail today. I will check the one under the fuse box also. I did have the fuse box partially removed in order to make removing the fog light wiring harness easier. So I'm intrested in checking this ground in particular.

            Thanks for the reply!


            -


            Will check back in later today. I greatly appreciate the help as always!




            Comment


              #7
              I checked everything and the last thing I did was unmount the underhood fuse box. The blue plug that plugs into the underside or bottom of the fuse box was disconnected. Which must've happened when I removed the fog light wiring harness.

              Thanks cloudasc and Raf99. My screw up. Much appreciated!




              Comment


                #8

                Comment


                  #9
                  I did the same exact thing! Have a thread about all of the things that don't work also once that plug is unplugged. Gotta love the little things we do to ourselves sometimes.
                  MRT: 1993 Honda Accord SE Coupe (Lola)

                  Comment


                    #10
                    Originally posted by Rilas View Post
                    I did the same exact thing! Have a thread about all of the things that don't work also once that plug is unplugged. Gotta love the little things we do to ourselves sometimes.
                    I didn't notice anything else that didn't work and I was surprised when I seen how many wires were in the connector. And I totally agree.




                    Comment

                    Working...
                    X