So I am posting this in desperation as I have no idea whats causing this issue. Long story short, my 2nd Gen FC has been having issues where the interior dash and guage cluster lights wont come on when switched on by the headlight switch. I initially determined its a fault with the switch itself, however I have since sent it out to be repaired twice and it is still not fixed. I am almost positive its a switch issue as when I jump the power to the pin for the interior lights on the headlight harness they have come on with no issues, its only when I plug it into the switch that they just dont seem to work. Harness is in mint condition and from what i was told its in perfect working order.
I'm wanting to see if anyone has any detailed advice on if theres something else I'm missing, or if it is the switch how a noob like me can teardown and fix it myself as I'm kind of at my wits end here. Every time I have sent out a package with parts for my Rx7 they have either gotten completly lost or have been a nightmare to get back so I really dont want to send this anywhere and risk losing this switch.

 

It sounds like you have to disassemble the switch and do some continuity tests.

It should be mentioned that this isn't an easy task for a novice. That switch is pretty complicated. That being said, depending on your skill level, buying a used switch may be a better option.

 

im not gonna get a new switch and risk that one not working as well. and remans are like $500 off atkins. I found a guy who would be willing to dissasemble it but he runs a phone repair shop so I'll need instructions on how to disassemble it. anyone able to provide any detailed teardown notes he can use?

 

Attached is light switch wiring diagram for S4 model. Your switch pin outs, as you've indicated above are correct. For Light that's R/G wire on the harness, for Ground that's B wire on the harness and for Power that's R wire on the harness. When you jumper power (R) to lights (R/G), you're bypassing the rheostat for the panel lights. Just to the left of the ground wire, there's an R/B wire. You can see that's the wire at bottom center of switch in the figure below. Do you get a voltage out of the wire when the harness is connected to the switch and the lights are turned on? If so, than that indicates that your rheostat for the panel lights is bad because it's also getting an input voltage but not producing an output voltage to your panel lights.

 

ok, then that basically confirms its the switch because your correct, I jump those wires and i get power to all the interior lights. Whats more, I jumped the white/green which is the actual power input for those lights to red/green and the lights turn on as well so its not a power issue (white green) and when jumping power to red/green which is load and ground the lights turn on without issue. With that being said, does anyone have a write up on how to tear one of these down? As much as you would think getting a new switch would be simple, every time I have had parts shipped to me or the other way arround they've either been lost, damaged or when they get here they dont work as described so I'd rather try and fix the one I currently have than risk another nightmare scenario like I've delt with half a dozen times up until now.

EDIT: actually, something really weird just happened. I resistance checked the 2 pins for interior lights (white/green and red/green) and when the switch was off there was no continuity but when the switch was on there was continuity with some resistance. Whats weird is it didnt matter what possition the dimmer switch was in, the resistance would be the same so I'm not even sure its the switch anymore. thoughts?

 

dumb question but have you checked the interior fuse box "illum" and "room" fuses?

there's lots of wiring in the car that can short out and pop those fuses, that diagram doesn't show them. i admit i didn't follow this thread closely but always start with the basics.

 

Here's a write-up I found on the web after Googling:
https://www.rx7club.com/2nd-generati...witch-1152865/
I think your problem may be in the dimmer on the switch's body rather than the PCB. There's most like a variable resistor that the dimmer **** controls. If the variable resistor is broken, than there's not much you can do to repair/replace it, as far as I know.

It's your call, but I'd just buy a used switch of Ebay. Here's one that I found on Ebay: https://www.ebay.com/itm/38885813888...YaAqotEALw_wcB
The ad lists this as 86-91 light switch. Supposedly S4 and S5 switches are interchangeable.

 

yes, first thing I did and while it was blown, I replaced it and it has not blown since. When I went through this with my windshield wiper switch, that fuse blew on install so I'm willing to bet this fuse blowing was due to the same thing.

edit: that fuse also powers the white/green wire which I also jumped to red/green in a previous comment and it supplied power to the lights with no issue. Wouldnt have been able to do that if the fuse was blown

 

absolute LEGEND! Everywhere I looked had a writeup but no acompanying pictures. I have a guy who knows how to work on PCB's and owns a local company but I wanted to give him a writeup before doing it.

as far as ebay, look at one of my previous responses as to why. TLDR, shipping companies suck in my area and packages consistently get damaged or lost. That, and the last time I had a package that wasnt either of those it ended up not working as described. I spent weeks dealing with that garbage before, I'd rather avoid it if at all possible