Removing "indiglo" faceplates & troubleshooting gauge li, They're ugly IMO and the needles don't light up. Options

[r3ck0n1ng]

Hi guys, nice to meet you! What an informative forum!!

I know this topic has been covered a million times but I have some annoyances and problems I've not managed to pinpoint or diagnose quite well on my 94 EU Celica GT. I have a number of issues with the "indiglo" or similar type faceplate that the previous owner had installed:

1) The speedometer reading is WAAAYY off. I think that this is because the previous owner installed faceplates reading in MPH (till 180mph) whilst the stock gauge reading was in KMH (till 180KMH - like JDM models) so when doing around 60KM/H its actually marking around 100KM/H - not practical. More on that later.

2) The faceplates are hooked up to a custom on/off switch and dimmer. This isn't a problem, as the faceplates do light up, but the most annoying thing is that the stock bulbs located in the gauge cluster assembly itself don't light up when the headlights are on, hence the needles and odometer/trip odometer are pitch black at night - not practical paired with the above point. I also want to add that the OEM dimmer located on the left side on the ignition plastic panel was connected, but still no lights on the needles. All other dash and centre console lights such as A/C, handbrake warning, oil level, door ajar lights, etc work normally, even with the OEM dimmer switch disconnected. (is this normal???)

There also seems to be a resistor of some sort hooked up with the green wire going to the socket of the dimmer, and I don't know what purpose it serves.

So to get to the point... Can I remove these aftermarket faceplates to reveal the original stock speedometer to restore accurate reading and get it hooked to light up normally? Is it normal that the needles and trip odometer do not light up when using these faceplates, or is it the OEM dimmer switch fudged? I'm no good with electrical stuff, so is it better to just take it to an electricians shop to sort it out? I can provide pictures if they might help.

Thanks in advance!!!

[r3ck0n1ng]

A very informative post indeed, I read it a while back and I must say its excellent, but I don't feel confident with tinkering on that level I also don't know if that method will be capable of adjusting with that much difference in reading though. Do you by any chance know if its possible to take off the aftermarket faceplates to reveal the original ones underneath or it was required to remove the original ones before?

The one I have right now is this



This is it lit up:



As you can see the odometer and needles are switched off

Below is the resistor I mentioned:

resistor

Should I just try to remove it?