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Suddenly blowing fuses


Suddenly blowing fuses

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    Suddenly blowing fuses

    Recently I was doing some work on my a/c and fan blower, so I had both the whole white fan cage and black a/c evaporator boxes out from under the dash. It seemed that I re-installed everything properly, however suddenly I am blowing 15A fuses [#11] that control the instrument lights, tail lights (though they light up for brake lights and signal lights), and the 'headlights are still on' chime. My headlights, corners, etc still work fine. I threw another fuse in and within 2 minutes it was blown again.

    I don't know much about these sorts of things, any guidance on how I may diagnose the problem?

    Check the glove box install, make sure you have not "pinched" the glove box light lead when reinstalling the pass. side dash/glove box.

    Also, if you have an aftermarket HU, pull it and make sure the illumination lead, [red/black] in the stock radio harness is not shorting to ground. there is also the harness that runs to the clock, it also has an illumination lead, make sure it has not gotten pinched off when you reinstalled the blower motor housing and evaporator box. 94


      All of those things looked fine.. since fuse #11 controls instrument lights, tail running lights, and license plate lights, I removed the connections from each one by one (disconnect all tail connections, put in new fuse, etc) and every time it still instantly blew the fuse. I did this all 3 times testing each one independently. Thus, it seems as though the problem is not coming from either of those 3 things.

      How could I still be blowing a fuse if none of the 3 are shorting out on their own?


        did you check the hu illumination wie? is it properly capped off?


          The short does not have to be at any of the load the fuse is powering, the short is in the wiring leading to the loads. 94


            I checked the HU illumination lead, orange/white since I have an aftermarket radio harness, and it is capped off properly.

            How exactly do you go about checking the actual wiring leading to the loads for the short?

            A couple of other points to mention- my dash brightness controller is slightly broken, in that the 'dimmer' can rotate so that the line is turned so far down that it is no longer visible; in the past the whole mechanism could only rotate the 60 degrees or so [line moving from bottom to top of visibility] but now can rotate 180+ degrees. Although, when I removed its connection, the fuse still blew.

            Also, I took my glovebox light out a couple months back, and so I sort of forget how it was powered- and there is no visible harness in the area that would power it.

            Lastly, after reinstalling my white fan cage, there are 2 grey connectors towards the bottom of the cage which are unplugged and have no apparent places to be plugged in..

            Thank you for the help so far, hopefully we can get this diagnosed because I cant drive much at night without my running tails..


              Unplug the "Dash Lights Brightness Controller" and see if fuse still blows, you will not have dash lights as the DLBC supplies the ground for those lights, [red lead] if the fuse no longer blows the short is in the DLBC and you will have to replace it, you can get dash lights by installing a jumper in the DLBCs plug to connect the black lead to the red lead, [full brightness] until you can get a new switch.

              The other possibility is the glove box 2pin light lead/plug, [black and red/black leads] you will need to find them to make sure they are not pinched off. 94


                how do I check for a short in the actual wiring?


                  What do you mean, "check for short in the actual wiring"?

                  You already know there is a short in the wiring, the fuse blows.

                  You can confirm the short with a multimeter, but that is not needed, at this point all you can do is find where the red/black lead is shorting out.

                  Did you find the glove box light leads, [red/black and black]?94


                    I have been very busy and not driving the car - I'm reinvestigating the issue on Friday, if the glovebox light lead is not being pinched, how should I go about looking for where a red/black lead is shorting out?


                      There is no simple way, all you can do is check the dash harness, the first places to check are at spots where things have been taken apart and wires possible pinched when put back together. 94


                        Is the only possible cause from a pinched wire?

                        How can a pinched lead from the glovebox light (or any component that is not controlled by the #11 fuse) cause that particular fuse to blow? Wouldn't it blow the fuse that is associated with THAT component?


                          Fuse 11 is the fuse for the clove box light.

                          The cause is because a lead, [red/black] is shorting to ground, why/how it is shorting to ground makes no diff., it is still a short and the fix is to find where the short is.

                          Because the problem happened after working on the "A/C and fan blower" it would make sense that the problem is in that area, the only "illumination" wiring, [red/black] in that area is the glove box light wiring.

                          The other posibility would be wiring in the main dash harness leading to the engine bay, [front park lights] however they are not hot, [live] untill park lights are turned on and you say the fuse blows as soon as you put it in. 94


                            Fixed it

                            I actually had the glove box male connector plugged into the a/c thermostat

                            The real a/c connector's wires are very short and I didnt see it tucked away in the corner, and used the longer glove box harness instead, heh. Surprisingly it clicked into place pretty easily too.

                            Anyway that solves that mystery and everything is all set now,

                            Thank you for the help!! You really are a valuable resource to this website.


                              LOL, the one thing I did not think of, wrong plug plugged in.
                              Glad you found it. 94