Dash lights not working.

Discussion in 'SN95 4.6L Mustang Tech' started by dmontzsta, Apr 22, 2006.

  1. I just had my head unit installed and also noticed my dash lights dont work. I have not used them in over a week, so I dont know if it is something the stereo shop caused, or something that happened and I just noticed.

    The dash lights work, but only if I click the switch in the dome light position. When they are in the dimmer position, they do not work at all. So right now I am driving around with no dome light bulb, just so I can use the bright dash lights.

    Anyone ever had this problem? Do you think it is something the stereo shop could have done?

    I dont really want to take it back to the shop, cause I know they are not going to do anything about it. My Dad seems to think it is the switch itself, but it works in the dome light position, so I am frustrated and stumped.

    Thanks in advance.
  2. I was told on another forum, that there is a wire that comes out of the harness for the dash lights. Anyone know more about this?

  3. mine is doin the same thing anyone got any ideas
  4. sounds like the blew a fuse.
  5. ---wiped---
  6. Assuming this is a 1999-2004 Mustang, let's start by checking fuse F2.37(5a) and F2.7(15a) in Central Junction Box (CJB).

    Confirm if the "door ajar" light is on.

    Confirm if the "rear window defrost swith", "Transmission Control switch", "fog light switch", and/or "Traction control switch" is illuminated when the lights are turned on.

    Please remember that many devices are actually controled by the GEM and not by normal "hard" wiring. The GEM module actions are based upon multiple input signals. The GEM provides the logic needed for things like power off delays and such.

    One possible explanation could be connectors "I1" and "D2" have been swapped at the main head light switch. But, I can not think of a reason that a radio installer would need to work in that area.

    Note, ground G203/G204 is near the center section by the radio. G204 is for the GEM module. I suspect many different (and bad) things will happen if not well grounded.

    Ground G204 is also the ground for the cluster illumination. Easy to see how the cluster lights will not work if disconnected.

    Confirm grounds G203 and G204 are connected. Maybe the installer disconnected while looking for a ground to the radio.

    I don't think it makes any sense to do any additional research until everything mentioned so far has been confirmed.

    Please review the attached diagrams.
  7. ---wiped---
  8. AKA3Toes; since you have a 88 Fox body, my previous comments do not apply. I am sure that you realize your post is in a section dealing with 1995+ Modular Mustangs (tech). The wiring of the two cars is very different.

    Consider opening your own thread as I doubt the OP's problem and your problem are the same. This avoids hi-jacking someone else's thread. Once done, PM me the link. It is also possible that there are guys much more familiar with the Fox cars than me.

    I have reviewed the diagram. No easy task as it is not a very clear scan. IMO, I really think that either the head light switch is wired backwards (more likely) or the Daylight relay is backwards.

    As a test, remove the Daylight relay and see if anything changes. If wired correctly, nothing should change execpt for the display on the radio (go out).

    If I am to be of help, better copies of the diagrams will be needed. It would also help to have a picture of the head light swich wires.

    If possible, confirm ground G201. Remove a panel light and measure the resistance from the socket to a known good ground. Should be low.
  9. ---wiped---
  10. No worries. As a update, I actually bought the entire headlight switch from Ford for about $50. I am sad to report that within about 6 months of having everything working great. One day I was driving along and my dash lights went out, the only way to get them to work was to click the switch over to turn on the dome light and take the dome light bulb out, that is how I have been rolling around for the last few months!:(
  11. Progress anyone?

    With all of the thread hi-jacking going on, I am not really certain exactly what everybody's symptoms are. Let's stick with the OP's stated symptoms of no dash lights after a head unit install.

    dmontzsta, Regaring your questions about the wire for the dash lights, the wire is actually the ground wire. All of the other connections to/from the dash are via factory connectors (can't be hooked up wrong). Again, if the ground to/from are not solid, the lights will not work.

    For that matter has anyone made any progress confirming the grounds?

    AKA3Toes, how about your own thread?

    TangerineGT96, Since your car is a 96, the wiring is different. However, the location/function of the grounds are similar. Any progress?

    To all, If an obvious problem is not found, some diagnostic work is going to be needed to narrow the cause down. The 1999-2004, 1994-1998, and 1992 and older are different enough to be their own animals. The different era cars need to be in their own threads.
  12. ---I had thought it enough that I was shown by you earlier that Google threw me into the completely incorrect forum... but since not, I've deleted my posts in hopes you can again regain your concentration.

    ---Thanks for everything all. Hope to also be posting here in the near future.