I've got a 1987 T2 that has your common dashboard light problem.

Headlights work fine, and so do brake lights, but only when brake pedal is pressed.

I have taken my gauge bezel out and checked out the switch and it appears to be in fine condition, along with the wire harness. Solder points appear to be fine. and harness is NOT burnt. Somebody must have replaced before.

Regardless, I went ahead and replaced both switch and harness with a S4 convertible parts. No difference I believe. And problem STILL prevailed.

Also checked ECU for any burnt terminals and I didn't notice anything.

Factory radio is missing, but all plugs are still there along with speakers plugs.

I've looked in various posts around the forum and online, but most that have the same issue is fixed by merely replacing said parts. Just about every one of them.

So, what I am asking is, is there anything else that controls lightning on the dashboard?

Circuit box?

Bad ECU?

Relays?

There is also other electrical issues with the car that I will not address unless you all feel the need to hear them. I will update at a later time.

Thank you all for the help before hand, and I hope to hear from you all soon.

 

CHeck Fuse box next to the clutch pedal should be the one labeled ILLUM 7.5 A

 

Thanks! But unfortunately, that's doesn't have any effect on the problem at all. The fuse is good!

 

What does this mean?

 

Sorry, I meant that as tail lights only work when brake is being pressed.

 

Sounds like a short in the wiring somewhere but check the tail light fuse I had the same problem in my 240sx and it turned out the tail light fuse controls the gauge lights and tail lights. Im not sure if the Rx7 is the same way or if that will fix your problem though.

 

The tail lights and brake lights share the same bulb as it is a dual filament bulb. It is possible that the filaments for the tails are both damaged or the bulb currently inplace is the wrong bulb and most likely a single filament bulb when it needs to be a dual filament as already mentioned. The other possibiity is the wire which provides the voltage to the bulb for tail light purposes does not have voltage on it when it should. Easy way to test that would be gain access to the back of the tail light housing and measure for voltage on the Red/Green wire w/the the headlight switch turned to the on position.

You also mentioned that your dash lights don't work? If so, do you have the dimmer **** turned all the way down?

 

Ok, so, things that need to be checked.

Number of filamentson bulbs.

Voltage on red/green with switch on.


Light switch in not dimmed down all the way when lights are on btw!

 

Cab, thanks for your input! Like you said, somewhere in the wiring of the vehicle there must be a short. I just wish I could find where!

There is a lot of info on the "classic" dash light problem, but unfortunately there's very little for mine. I think my best best is to find a website with various wiring diagrams for the rx7.

Suggestions?

 

EDIT: The wire in the rear you could check for voltage w/the light switch on fotr the tail lights is Red/Black and not Red/Green as previously mentioned.

The headlight switch harness has a Red/Green wire that should have voltage w/the headlight switch **** turned to the first position. The Red/Black wire that powers the tail lights is also in this harness and it too should have voltage with the switched turned to on. I bet neither do!

Wiring diagrams: Foxed.ca - Mazda RX-7 Manuals

 

Sorry for not writing a proper reply at this moment. I've been unable to get around working on the car. Will update as soon as I check