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Topic: Dash lights? (Read 856 times) previous topic - next topic

Dash lights?

hi guys, i need some help. i have a 1985 with the digital cluster
 when flip the switch to turn on the headlights the dash lights go out? then i turn the headlights back off and the dash night turn on??? all the fuses look good?

and suggestions??

Dash lights?

Reply #1 –
yes
remove cluster and replace bad bulbs.

Dash lights?

Reply #2 –
fixed, i took the light switch out and found two little brown wires, when i turned the light on the power was turned on at the two wires. so i cut one of the two and bam! it worked.

Dash lights?

Reply #3 –
Quote from: dailydragger;298097
fixed, i took the light switch out and found two little brown wires, when i turned the light on the power was turned on at the two wires. so i cut one of the two and bam! it worked.


I would be looking for the real problem, not cutting wires that are designed to be connected as you originally found them.

The two brown wires off the headlamp switch serve two seperate circuits on the printed circuit on the back of the instrument cluster for LCD digital readout illumination. The first thing you need to do to find the real problem is reconnect the cut wire.

The full digital cluster is back lit with dual bulbs behind each LCD digital gauge readout. In the daylight, both bulbs light up with the ignition key for optimal daylight visibility. When you flip the headlight switch on at night, it switches one bulb off behind each digital gauge readout to dim the cluster when it is dark outside. You cut the circuit that keeps the cluster fully illuminated during the day.

If you have a full digital cluster and none of your lights come on at night then you need to pull the entire cluster and look for a bad connection between the cluster harness connector and the printed circuit contacts it engages on the back of the cluster. Check the printed circuit itself as all the bulbs share the same printed circuit run.

If you have a full digital cluster and the cluster is partially lit, you need to check for bad bulbs and sockets that are loose and wont engage the contact area on the printed circuit.

On the standard cluster with only the LCD digital speedometer readout, only the speedometer has dual bulbs which one dims at night and the one is always on with the ignition key. The remaining buttstuffog gauges simply have conventional backlighting that goes on and off with the headlamp switch.

In the case of the standard cluster, it is usually one bulb of the two that goes out behind the speedometer readout. If you can read the speedo during the day but not at night, it is usually the bulb out that stays switched on with the ignition key. If the brightness of the LCD readout does not change with the headlamp switch turned on, then it is the bulb is out that switches off with the headlamp switch turned on.

Dash lights?

Reply #4 –
Did you by chance check the dimmer to see if it was all the way off?????????

Dash lights?

Reply #5 –
I have no frigging idea what dailydragger is talking about.  Whatever it is, sounds like he's happy.

watchdevil

"""""""On the standard cluster with only the digital speedometer readout, only the speedometer has dual bulbs which one dims at night and one is always on with the ignition key. The buttstuffog gauges simply have conventional backlighting that goes on and off with the headlamp switch. """""


Not true, both bulbs light up with the same intensity day or night.  Many of our cars do not have the autolamp sensor on the dash.
Never does one bulb burn brighter than the other in the conditon you describe.

Dash lights?

Reply #6 –
Quote from: jcassity;298159
I have no frigging idea what dailydragger is talking about.  Whatever it is, sounds like he's happy.

watchdevil

"""""""On the standard cluster with only the digital speedometer readout, only the speedometer has dual bulbs which one dims at night and one is always on with the ignition key. The buttstuffog gauges simply have conventional backlighting that goes on and off with the headlamp switch. """""


Not true, both bulbs light up with the same intensity day or night.  Many of our cars do not have the autolamp sensor on the dash.
Never does one bulb burn brighter than the other in the conditon you describe.


Let me correct this for you because I did not mean to say that one bulb dims. I meant to say one goes off completely to dim the readout at night therfore reducing the light output from behind the gauge readout.


I am experienced replacing the bulbs in the clusters of many of these cars over the years and my own former 1985 Tbird with just the digital speedo.


The problem I had with my own 1985 Tbird was the speedo readout was lit but not bright enough to see in the daylight but sufficient for night. One of the two bulbs side by side behind the speedo readout was out. I replaced the burned out bulb and it came to full brightness as it should during the day. Put two 194 bulbs together side by side and you get double the light in a concentrated area. Turn one off and the light output reduces. The LCD backlighting does not operate at full intensity at night. One of the two bulbs turns off when the light switch is flipped on. This dims the LCD gauge so that it will not be too bright at night.

The cluster does not operate by dimming the light output of any individual bulb when the light switch is turned on. It just turns one of the two bulbs off behind the LCD gauge cluster.

The light output of each bulb is only reduced when you operate the instrument panel dimmer switch at night.

The autolamp function also does not affect the brightness of an individual bulb. If it gets dark outside, the autolamp sensor on the dash simply switches the headlamp switch on instead of you doing it manually.
 

Dash lights?

Reply #7 –
i only did this for a temporary fix. this is our only means of transportation so i HAD to fix it soon and this was one of many problems with the car and i needed to fix them all before our baby comes. ill fix it right when i get a break in December.


thanks for all the info im sure ill be back to ask more questions on this later.