Left and Right Pods on Dashboard

[48Rubles]

We are a new owner.  Dashboard and touchscreen is working.

 

Are the pods on the left and right of the dashboard where the light and windshield wiper switches are supposed to be lit up? have some kind of backlight so you can see the switches at night?

 

thank you

1989 Buick Reatta

[Ronnie]

Welcome to the forum! Yes, the light and wiper switches have back-lighting. Try sliding the dimmer on the headlight switch to the right to see if the back-lighting of the switches gets brighter. It should also brighten the touchscreen and the speedometer etc. If the touchscreen is too bright it can be dimmed separately through adjustments in the touchscreen settings.

[48Rubles]

We are a new owner.  Dashboard and touchscreen is working.

 

Are the pods on the left and right of the dashboard where the light and windshield wiper switches are supposed to be lit up? have some kind of backlight so you can see the switches at night?

 

thank you

1989 Buick Reatta

---

The slider does not do anything to the dashboard. I have tried it several times, no backlighting on the switches. How fix or what to replace? Thank you

 

1989 Reatta

[kdirk]

First, welcome aboard from a fellow Missourian (I'm in St. Louis).

 

Ok, a couple of things. First, at night, check and see if you can adjust the brightness of the touchscreen. This is done by entering status / set brightness. If it is dark out and the park or headlamps are on, you will be able to adjust the screen brightness. If it won't let you set the brightness, and the screen shows the message "darkness required to set", then the twilight photocell (located center top of dashboard below plastic trim pad) is bad. This photocell tells the computer when it is dark outside, and the switchgear backlighting and adjustment of touchscreen brightness will not work if the photocell has failed fooling the computer into thinking it is still daylight out.

 

The digital displays on the instrument cluster will also normally dim slightly when dark out and the park or headlamps are on. If the cluster doesn't dim about 10% (maintains full brightness instead) then the photocell is not signalling darkness to the computer, and will need to be replaced. The dash switch pods will not light up at all unless the computer "thinks" it is dark outside. There is an override for this in on board diagnostics. More on that later, if needed.

 

If the photocell is good, then there are other possible causes. One is a failed inverter. These switches use electroluminescent backlighting driven by a 110 volt AC power source. There are two inverters. One is located up inside the dash on the driver's side below the dash pad and behind the headlamp switch pod not far from the windshield VIN plate. This one is very difficult to get to from under the dash but can be done with determination. It is a small plastic box that is pink in color with a yellow warning label cautioning of high voltage. This one powers the backlighting for the two dash switch pods.

 

The second one is located in the center console, under the trim plate and ashtray. It is the same shape and size as the pink one, but is black, and has the same yellow warning label. This one powers the gear shift indicator, power window and mirror switch legends. One can be good and the other failed, so it is possible the dash switch pods will be out while the console switches and gear indicator are still working, or vice versa. If your center console indicators are all working, and the border button legends on the touchscreen light up normally at night, then the dash (pink) inverter may be suspect. But, there are still two other causes to be considered.

 

The next possible issue is with the switch pods themselves, or the associated wiring (the latter being less likely). The headlamp switch controls power to the inverter that illuminates the EL backlighting. If there is an internal fault within the switch, the inverter may not be getting 12VDC input and therefore no high voltage output is present. I have had at least one headlight switch cause intermittent loss of power to the inverter due to mechanical wear within the switch. Also, as a safety feature, there is a circuit that consists of two grey wires looped through each switch to detect if any of the EL lighted switches are disconnected. If this loop is broken by a switch being unplugged, or a break/cut anywhere in the grey wires that comprise this continuity loop, the inverter will shut off to prevent risk of electric shock. The console inverter circuit is configured similarly.

 

One final possibility is that the EL material itself is burned out. EL strip has a finite lifespan, as it continuously loses a small amount of brightness over a long period of time, until it gets too dim to be useful. It can, however, burn out entirely in certain circumstances. In either of these cases, the only remedy is to find a replacement switch with good EL in it still. Clearly, at this point, that is getting more difficult - but not impossible - due to age of used parts and general lack of new ones being available. I listed this one last as it is unlikely both tour switch pods died at the same time, and that the photocell or inverter are going to be the more likely cause of the problem.

 

I would suggest testing the photocell functionality first and identify (or eliminate) that as the cause since it is fairly easy to do. To test the inverter output you'll need to backprobe the correct terminals on the headlamp switch (or at the inverter itself, but it is easier to check at the switch pod) with a volt meter for the presence of 110 VAC.  Not knowing your level of comfort/troubleshooting skills and whether you have a factory service manual, I won't detail those procedures just yet, and can do that in a follow on post if needed.

 

Kevin

[Ronnie]

Kevin, Thanks for the great information on how the backlighting works. I learned a lot from it.