Dashboard light issue

[doncaruana]

Recently I've had an issue with the dashboard lights on my 97 Tahoe. The light switch works fine for the headlights but it won't control any of the interior lights (cluster, radio, dome, etc) UNLESS...you give a tap on the top of the dashboard. It would work for a while like that and intermittently have the same issue - and solution - again. Not a real hard smash either, just smack it lightly (my daughter, who drives it now, came up with this solution). I didn't realize this was a persistent issue until recently and then last night she tells me the smack-the-dashboard solution doesn't work either anymore. I had replaced the light switch a few years ago so I thought maybe that was it and ran up to Autozone and got a new replacement switch, but no change in behavior. I then was thinking maybe it's just the cluster, but it's the other lights as well.

So now I'm at a loss...Can anyone suggest what the real root cause and solution are for this? I'd pop another cluster in but I have zero faith that would solve the issue. I actually still have the one I pulled out of it a few years ago where the oil gauge lost its mind, so I could try this if anyone thinks it might actually be the cluster.

Much appreciate any feedback or suggestions.

 

[wjburken]

Where was she tapping the dashboard? Was it near the switch or on top above the cluster?

I’d double check your switch assembly and make sure it’s not the item flaking out.

The fact that is affecting the dome light, radio and dash leads me to look at that first and not your dash cluster.

 

[doncaruana]

Where was she tapping the dashboard? Was it near the switch or on top above the cluster?

I’d double check your switch assembly and make sure it’s not the item flaking out.

The fact that is affecting the dome light, radio and dash leads me to look at that first and not your dash cluster.

Left hand side, above the actual switch. No idea if doing it anywhere else would have worked.

When you say "switch assembly", what do you mean though? I replaced the switch itself and that didn't help at all.

 

[Hoesgottaeat2]

I believe he’s referring to the light switch assembly with the dimmer wheel and override button on it. Easy place to start….again unfortunately

 

[wjburken]

I believe he’s referring to the light switch assembly with the dimmer wheel and override button on it. Easy place to start….again unfortunately

That is what I was referring to. I would also check the wiring at the harness to see if you have any loose wires.

 

[Hoesgottaeat2]

That is what I was referring to. I would also check the wiring at the harness to see if you have any loose wires.

Agree…

 

[doncaruana]

I replaced that switch first and no difference. Also my daughter clarified it was pretty much anywhere on the dashboard but mostly she'd just do it right in the middle over the steering wheel.

I'll pull the instrument cluster anyway. Just seems weird that the dashboard smack would affect a loose wire without it being real hard unless the cluster was involved.

Ugh. I don't expect this to be easy.

 

[wjburken]

I replaced that switch first and no difference. Also my daughter clarified it was pretty much anywhere on the dashboard but mostly she'd just do it right in the middle over the steering wheel.

I'll pull the instrument cluster anyway. Just seems weird that the dashboard smack would affect a loose wire without it being real hard unless the cluster was involved.

Ugh. I don't expect this to be easy.

Electrical stuff can be very frustrating. Just need to walk through it and be thorough.

 

[east302]

Here are the diagnostics from a 98 manual, it’s probably the same for 97. Maybe it will help. Make sure that fuse 14 isn’t blown and that the ground (G200) is tight. It’s on the crossbar kind of near the OBD connector.

 

[doncaruana]

Here are the diagnostics from a 98 manual, it’s probably the same for 97. Maybe it will help. Make sure that fuse 14 isn’t blown and that the ground (G200) is tight. It’s on the crossbar kind of near the OBD connector.

View attachment 388560
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A ton of info in there! I took out the cluster and tried my old one on a lark, of course no change.

I have a dumb question though... Based on the diagram above, it looks like the common element is the "GRY (8) wire between Splice S217 and...", so my thought is that gray wire is broken loose from splice 217. Given my daughter's "fix", presumably that is upwards in the dash, likely right behind the instrument cluster (if that makes sense). And according to the same info, splice 217 is located at "IP Harness, approx. 16 cm from Instrument Cluster Harness Breakout, toward Radio Connectors Breakout". Is there a way to get to any of that wiring short of pulling the whole dash? When I pulled out the cluster, there is a thick set of wires I can get to on the right side, but I didn't look at them closely.

Note that the ONLY thing not functioning is the illumination aka all the stuff attached to dimming. Everything else is working - light on 4wd switch, the radio, the ac, dome light switch, and headlight switch. Even all the cluster warning lights are working.

UPDATE: The meter test under the "Instrument Panel Lamp(s) are inoperative" section yielded no voltage (technically -0.7), which tells me "CHECK for an open or high resistance in DK GRN (44) or GRY (8) wire between Headlamp and Panel Dimmer Switch and Splice S217. If OK, REPLACE Headlamp and Panel Dimmer Switch." Same question applies...how do I get to splice 217?