'93 GrandAm Headlight Problem [Archive] - GrandAmGT.com Forum


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09-23-2005, 12:19 PM

I am new to the group here in search(did a search and found 34 pages that did not help) of some Technical assistance with a '93....The Headlights do
not work. I have checked the Voltage to the Low Beam plugs and note
12v. Upon installing a Lamp, the Voltage drops to zero, either side,
same result. The High Beams will only work when the Multi switch is
held for High Beam activation, otherwise no lights either. When the
Hight Beam Multi switch is activated and not held, only 5v is present
with an extreamly dim Dash indicator. Following the Haynes Repair
Manual, the Schematic shows only 2 sources of failur points, The
Interior Dimmer Switch and a Lights Monitor Module. I beileve I have
rulled out the Dimmer, but have no clue where to find the Lights
Monitor Module.....Any assistance is greatly appreciated..


09-28-2005, 02:39 PM

09-28-2005, 02:47 PM
What was the problem. You should post that so that if other have this problem they can search for it. Fuse?

09-29-2005, 05:36 AM
OK, will do...I figured due to the lack of any feedback to a newbie on this particular board, no one really gave a ****.... :thumbs:

The problem ended up being the Multi-Switch that controls Headlights/Park/Cruse. Followed a written procedure from another person on another GA group that identified the problem…Simple action of cleaning the contacts and all is good…Here is the procedure:

What you described sounded very familiar. But...

I was able to fix my headlights this afternoon! It turns out that
the problem was the switch that controls both high and low beams
(the "off/Park/Headlight" switch on the "multi switch lever"). I
pulled the steering wheel, removed the switch module and then took
it apart. The section that controls the headlights can be unscrewed
from the module. When you pull it off, there are two actuators from
the lever. One of them slides the "off/Park/Headlight" switch and
the other pushes on the "High Beam" switch when you pull on the

The off/park/headlight switch consists of a plastic block with
two "shorting bars" that slides across "contacts" on a printed
circuit board. You can simply pull the plastic block out of the
assembly. The shorting bars are spring loaded so they maintain
contact with the circuit board. In my switch, one of the shorting
bars was "stuck"- its spring wasn't pushing it down to the circuit
board contacts. So, the switch was never making contact and the
headlights were never being turned on. The other (working) shorting
bar controlled the parking lights.

The circuit board was also very dirty (tarnished- pitted). I doused
a Q tip with contact cleaner and cleaned it up. Contact cleaner
also did the trick of freeing the shorting bar and restoring its
spring tension. I put it back together and now its working.

One thing that threw me was that my high beams were working (so I
had assumed that the headlight on/off switch was ok). The "high
beam" switch in that assembly is a momentary switch that "flashes"
the high beams on when the low beams are off. This switch bypasses
the off/park/headlight switch. So the high beams could still work
(momentarily) even if the off/park/headlight switch was bad. I'm
not sure how it switches between the high and low beams or how this
momentary switch keeps the high beams on during normal operation.
There must be an electronic module of some sort that switches
between the high and low beams and allows momentary operation of the
high beams when the off/park/headlight switch is in the off or park
positions (maybe that's what that "Lights Monitor Module" does).

Getting to your problem, I really think that the strange voltages
you're seeing are "phantom voltages"- they come from a very high
impedance source (like maybe an input to an electronic module). If
you loaded it down with anything it would go away. If you measured
them with an analog voltmeter instead of a high impedance digital
multimeter it probably wouldn't be there. I think that's why you're
seeing a voltage until you plug one of the two headlights in.

I'm not sure about your high beam indicator, though. Mine never lit
dimly. If the high beam lights were disconnected the indicator
light might get enough leakage current from the "Lights Monitor
Module" to light dimly.

I suggest you take a look at your headlight switch- it was definitely
the problem in my case. I took some pictures, and made some
sketches while I had it apart. I could give you more details if you
needed them. Let me know- I could either upload the pictures on the
Yahoo site (I think?) or email them directly to you.

Good luck! Keep me posted.
- Larry

What was the problem. You should post that so that if other have this problem they can search for it. Fuse?