Dash Light Illumination Not Working

lgaskins0915

Member
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2002 Mazda Protege5
Hey guys, its my first post here and I can't seem to find this anywhere in the forums. I recently bought a P5 and couldn't be happier. I decided to upgrade the stock stereo to a Double DIN with navigation. I did use the Mazda Wiring Harness and the only issue I had was the Illumination wiring. I had 2 wires on the Mazda Harness (orange and orange w/white) that were labeled "Illumination/Dimmer". I spliced them both to the radios single Orange wire labeled "Illumination". Everything worked great, radio turned on fine, everything works, was wonderful. Upon dark I turned on my lights and the dash illumination lights did not come on. The radio also dimmed. I have checked all my fuses and I have no idea what went wrong. Even hooked up the stock radio and the lights still do not work. Any help would be great, thanks!
 
I checked the audio wiring schematics and it doesn't show any orange wire. I'm thinking that by putting the orange and the orange/white wires together you may have sort of grounded out the dimmer circuit,... similar to turning the illumination dial all the way down. I would try using either the orange or orange/white wire alone. I'm thinking one of them will allow dimming of your stereo and the other will be full brightness all the time. I'm just thinking that you're not supposed to join those two wires togther.
 
Check your lights, I had a similar situation happen, and the taillights didnt work aswell. It blew a fuse because upon reinstalling my stereo in the dash. i pinched a wire shorting it out I believe it was a blue wire. This was over 3 years ago so im not sure. Brake lights and headlights worked, and that was it. Check your fuses, and check your installation
 
btw you definitely want to separate the illumination wires, and tape them off so they cant short out
 
OK I checked all the fuses twice, all are intact including engine fuse and interior fuse. I pulled out the dash and replaced the gauge bulbs which did look kinda black and grimy. New lights did not turn on. All other lights work including headlights, taillights, fog lights, and running lights.. "Door Ajar" and "Brake Light" both come on. I hooked up the old radio which didn't help at all. Dimmer knob is all the way up. Worried I'm going to have to go get it checked out at a car place...
 
Did you disconnect the two orange wires from each other ?? You may have fried your dimmer circuit.
 
As an additional note. I have the radio completely out and when I flip the lights on the "Outside Air/Circulate Air" light dims. All the other lights on that console are also out though =[
 
I think you might have fried your dimmer dial circuit. There is a test procedure in the service manual on page: 9-18-25
The dimmer doesn't reduce the voltage to get dimmer lighting, it instead pulses out full power with shorter and shorter intervals. I'm pretty sure a regular voltmeter would show that and I'm almost positive an old school meter with a moving needle would work to test it. The mechanical needle would absorb the bouncing pulses of voltage and give a steady reading. I don't think an oscilloscope is needed like they say in the manual.
I'm pretty sure you could 'bypass' the dial with a jumper but I'm not sure which terminals get shorted,... that way you'd have dash lights but at full brightness. (I'm having a hard time following the circuit diagram)
You may of course just have a blown fuse somewhere,... they mention the TAIL 15 A fuse.


OK,.. I stared at the circuit diagram again and I'm around 90-95% sure that if you disconnect the dimmer dial and jumper the B+ to the C terminal (light green with a black stripe wire, with the white with a blue stripe wire,... that's the two middle terminals,... one side of the plug is empty and the other is ground,... don't jump anything to ground.), it will give full brightness on all your dash lights. You would do that at the connector not at the dimmer dial. If your dash lights come on then you know it's the dimmer dial and you've got lights until you get a new dial,... perhaps at a junker for a few bucks.

I just noticed your post about the "recirculate" light dimming,... if you disconnect the dimmer dial and your "recirculate" light goes back to full brightness then it's almost for sure that the problem is your dimmer dial.


PANEL LIGHT CONTROL SWITCH REMOVAL/INSTALLATION

1. Disconnect the negative battery cable.
2. Remove the driver-side side panel.
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.

Panel Light Control Switch Removal Note
1. Insert your hand into the hole in the driver-side side panel, grasp the tabs of the panel light control switch and
pull it forward to remove.

1 Screw
2 Connector
3 Door switch

1 Panel light control switch
(See 09–18–25 Panel Light Control Switch Removal Note)
2 Connector

LIGHTING SYSTEMS
09–18–26
PANEL LIGHT CONTROL SWITCH INSPECTION

1. Remove the panel light control switch. (See 09–18–25 PANEL LIGHT CONTROL SWITCH REMOVAL/INSTALLATION.)
2. Connect the negative battery cable.
3. Connect the connector to the panel light control switch.
4. Measure the voltage at the panel light control switch as indicated below.
5. Disconnect the panel light control switch connector before inspecting for continuity at terminal D.
• If not as specified, inspect the parts listed under “Action.”
• If the parts and wiring harnesses are okay but the system still does not work properly, replace the panel light control switch.
Terminal Voltage List (Reference)

Terminal C inspection
1. Measure the wave pattern of the C terminal on the panel light control switch using an oscilloscope.
2. Set the headlight switch to either the TNS or headlight position.
3. Set the panel light control switch to the brightest position.
4. Verify that the pattern on the screen is as shown in the figure.
Terminal Signal Connected to Test condition Voltage (V)/Continuity Action
A — — — — —
B TNS TNS relay
Headlight switch at TNS or headlight position B+ • Inspect TNS relay
• Inspect combination switch
• Inspect TAIL 15 A fuse
• Inspect related harness
Other Below 1.0

C Illumination Each illumination Inspect using an oscilloscope
(See 09–18–26 Terminal C inspection) —
• Inspect each illumination
• Inspect related harness
D Ground GND Constant: inspect for continuity to ground Yes • Inspect GND

LIGHTING SYSTEMS
09–18–27

5. Verify that the pattern on the screen matches the pattern shown in the figure as the panel light control switch is gradually turned to the darkest position.
 
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Going to check out the dimmer switch when I have time at the end of the week. Would that be the dimmer switch coming off the steering wheel or the dimmer dial near the fog lights? Can't seem to find the one near the fog lights at my local auto store.
 
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The dial near the fog lights. It looks like it might be a Mazda specific part and maybe expensive too,... It's kinda fancy inside.

They call it a "panel light control switch" in the manual.

They don't seem to have it at Rockauto,... the "Dimmer Switch" they list is the turn signal lever.
 
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Reading some further reviews. It sounds like the "panel light control switch" is ran by something called a "INSTRUMENT LIGHT RHEOSTAT" which controls the resistance to the lights on my dash. Online easy fix is just to run a small wire between the two contacts to replace the current. Any opinions? If this is the case could I get a cheap aftermarket "rheostat" and just solder it in there? Thanks again for all the help guys, driving around with a light on to see my panel is very annoying!
 
I'm almost sure you can just run that wire that you mentioned, between the terminals,... that will give you full brightness but it won't be adjustable. The rheostat may very well work but you need to know the number of watts it would need to handle. The rheostat is just an adjustable resistor in series with all the panel lights which works but creates a lot of heat compared to our specialized dimmer circuit. Our circuit uses transistors and a rheostat uses finely coiled resistance wire.
If I were you I'd short the contacts giving you full brightness and time to find one at a junker and maybe have it mailed to you. (you might need to disconnect the dimmer dial before you jumper it because it's dimming your other lights in a weird way).
 
If you can, just jumper the switch - i would just do that - i always had the lights on their brightest (and they were still kinda' dim)...
 
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