Dash Light Issue & I’ve Checked Previous Threads….

[yungnbord]

I’ve read the threads I was able to search out on my problem but can’t seem to find a solution. Here is a description of what is occurring for me…

I have an 87 that the dash works fine when the headlights are off. As soon as I turn on the headlights I can no longer see the speed, RPM and so on. I can still see the high beam indicator and turn signals. At times when I turn the headlights on the speed and RPM are lit but then slowly dim until they are all the way dark.

Today I removed the faceplate to check the 4 bulbs, they were fine. The light sensor seemed to be working as I can shine the flashlight at it and the bulbs will get brighter. I then turned on the headlights and I watched the bulbs slowly dim down over about 40 seconds. I then, with the headlights on, shined the flashlight into the light sensor and the bulbs brightened back up.

Any ideas?

 

[vetteboy86]

Probably a stupid quesiton, but that headlight switch turns to dim the lights. Is it possible there is a malfunction here in the switch that when it is pulled out the lights dim.

 

[wildbill486]

Here's something that might help. Mine's doing the same thing and I found this fix which starts with the same symptom. Can't find the link but luckily, I saved it.

"One of the most common problems is the dash lights will go dim and the high beam and turn signal lights come on. When the dash lights are inoperative and the high beam and directional indicators come on dim, look for a bad ground. The most common problem is a poor dash ground on the 153 circuit. This is a black/white striped wire in cavity D3 of the large connector (Fig. 1) to the cluster. This wire goes to an ambient over-ride sensor (Fig. 3), then to the bulkhead connector to cavity B1 to the engine harness wire to the left rear of the engine.
The ambient over-ride sensor (Fig. 3) is located under the dash on the backside of the bulkhead connector on a plastic cover over the wires entering the connector. It is about the size of a dime and 1/2-inch thick with two terminals. One is the 153 circuit. The other returns to the cluster to cavity D7. This is a 911 circuit and is a dark blue wire. The purpose of the ambient over-ride sensor is when the temperature drops low in the northern areas the LCD will still illuminate.
Ground the 153 circuit, black/white stripped wire, by attaching a ground wire at the over-ride."

 

[Mart]

Here is the link to the problem I had that sounds the same.

This fixed mine right up.

http://batee.com/corvette/dcrg/removing_ip.htm

Mart

 

[yungnbord]

Mart,
Was your LCD Display itself out? Mine seems to be working fine... it seems to be more along the lines of something to do wtih the 4 "backlights" and not illuminating the LCD display properly. Is it something on those circuit boards that is controlling the lights themselves? I only ask becuase I briefly went through the solution and I will admit it looks a bit scary!

 

[Mart]

I thought it was pretty scary as well, but it is pretty basic. it turned out mine was one of the connections, after the soldering it worked great.

Here is a link to more info from the same site, different page.

http://www.batee.com/corvette/dcrg/problems.shtml

Check to see if one of these problems sounds more like yours (Maybe #2)

I was nervous when I dug into it but it was nothing. And a replacement is not cheap at $400, worth the shot.

If you ever need help we're here.

Mart

 

[oldvet]

Wiggle your headlight switch shaft from side to side and see if the problems is elimanated.

 

[yungnbord]

Unfortunately I've not had time since the weekend to address any of the items... I sit with the dash out and screws in the center counsel! I did however have time to try the "wiggling" of the light switch and nothing happened. As soon as I turned off the headlights the bulbs once again went to full brightness. Unless there are any other ways to troubleshoot I think I will try the "pulling out of the LCD panel itself. Thanks for everyone's help so far... what a pain of a problem!

 

[oldvet]

If the dash works when heakights are off, the panel is in working order. Go to the grounding techniques next, as messing with the panel without grounding strap can cause harm to the panel.

 

[yungnbord]

OldVet what do you mean by grounding techniques? I'm a bit lost here? Thanks for the input.

 

[oldvet]

Go to; www.batee.com , he has a learning article for your ground problems.

 

[Mart]

Hey guys, where do you think I have been sending him, the main problems revolve around grounding and includes the resoldering of some pin connections.

Mart

 

[yungnbord]

Thanks guys, Mart I'm guessing there was just some additional things to try to isolate the issue! I'm going to give it a go this weekend and will let you all know the results! I really appreciate the feedback from everyone.

Erik