boostd4

iTrader: (4)

Thought I'd post up for some help. I've been searching for the last hour and read through a bunch of threads about people who've had their tail lights go out, but they also have their parking lights and dash lights go out at the same time.

On my car, EVERYTHING WORKS except the tail lights. I haven't checked to see if the dimmer actually dims, but the dash lights work fine.

I will check the TNS relay up front, but could only the tailights go out if that relay dies? Doesn't it control more than just the tails?

The tail light fuse under the driver's side is good. Any other suggestions?

DaleClark

iTrader: (55)

Also check the plug to the CPU in the driver's side kickpanel. If it's unplugged or not plugged in all the way you'll get taillight weirdness.

Check all fuses of course.

Dale

boostd4

iTrader: (4)

Ugh... I think I'm moving in the right direction, but I wish it could just be a simple relay problem. What I've done so far:

1) Swapped Retractor Relay and TNS Relay (no change, retractors still worked, rear tails, parks, and lic's out), so it's not the TNS relay. I tested both relays out of the car, and they click, and the TNS relay also audibly clicks when I turn the headlight switch to the first click.

2) Cleaned the grounds for the front relay box harness - no change.

3) Checked for voltage at the 15A Taillight fuse in the driver footwell. 12.6V on both sides of the fuse at all times. At first I was like, WTF? even with the switch off? But the fuse only protects the circuit and is before the switch, I guess (?)

Now, on to the wierd part... I was messing with the front relay box right after work. It is ziptied to the rad core support and I can't get to the relays without cutting it down off the zip ties. This is when I pulled the TNS and retractor and tested them, verifying they work fine. I didn't touch any other relays. After no change and it was getting dark (remember, no tail lights) I decided to go home.

It was dark by the time I got home and nobody pulled alongside to tell me my tailights were out ... strange, but not impossible. I pulled into the garage and saw the reflection of my tailinghts on the door! Everything was working. Now the strange part...my Bose Wave subwoofers did NOT work the entire way home and they worked fine on the way to work (even with the tail lights out). I turned the car off and went inside for about 30 minutes. When I came back out to the garage and checked the tail lights, they were back to not working! Now I have no taillights and no rear Bose subs.

My guess is that there has to be a spot where the harness to the rear of the car is getting pinched. The radio works, and the front speakers work so it's not the RADIO relay in the TNS relay box or other electrical gremlins from that relay box since both the front parking lights and the front speakers work.

Anybody who's had the interior out and re-installed the rear sections of the harness have any tips for where I should look? I won't have time to yank the rear plastics out until Sunday but want to have my ducks in a row.

By following this wiring diagram:



Following the electrical path (am I doing this right?) it seems power first goes to the front lights of the car, then it splits to the upper branch (CPU1,2, glove box light, dash lights) and then to the rear via JB03, which is pictured here:



I really hope that's accessible without removing the instrument cluster. If it isn't, I'm going to work my way backward from the tailights Since I have power everywhere but after JB03, I'm guessing it has to be a shorted wire. I don't see any other connectors that send power to all of these things after JB03 (BTW, what is the circled "E" after JB03 mean?).

Any comments, criticisms are greatly appreciated. I'm not a complete electrical noob, but I haven't had an RX7 apart yet.

7dust

iTrader: (14)

My car hasn't moved in the last year. I am buttoning up my engine swap and no tail lights or windshield wipers here.

I'll be watching this thread to see how you get this ironed out and I'll be sure to report back if I get any ideas for yours - while troubleshooting mine.

Ernesto13B

iTrader: (4)

Having 12 Volts at the stop light fuse all the time is normal, because like you said it's before the brake switch. The only thing that that prevents the brake lights from being on all the time is the brake switch. The brake switch is normally an open circuit so that way your brake lights arn't on all the time. Only when you press the brake pedal does the circuit complete and the 12 volts make its way from the brake switch to the tail lights.

That diagram you have is perfect for diagnosing, what I did when I had a problem with my brake lights was I drew a red line highlighting the entire brake light circuit so it doesn't seem as frustrating. I would start diagnosing from the battery and slowly go from there and work your way to the brake lights. I had an issue with my brake lights staying on all the time which is opposite of the issue your having, but here's my thread, hopefully this helps.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/tail-lights-all-time-not-brake-switch-879067/

boostd4

iTrader: (4)

You might want to take a closer look at what this thread is about

My brake lights work fine... it's my TAIL lights that don't work.

Ernesto13B

iTrader: (4)

Oh my bad I mixed em up lol but diagnosing is the same for any electrical problem. For me its always easier to start at the battery first and work your way to the end of the circuit, the reason why is because you start where the power starts. Eventually you will come to point to where you will find no power, and thats how I found my problem.

boostd4

iTrader: (4)

Gotcha. The hard part is that according to the diagram I posted, power now goes either way... I know that I have power up to the RF side marker light and after that, power splits to the rear, and to the front glove box.

I've been meaning to do a sound deadening project on the rear of the car anyway, so I'm going to pull the rear interior out this weekend and work backwards. It won't be a waste of time since I have to pull that stuff out anyway.

7dust

iTrader: (14)

Wish I could be of more help. My problem turned out to be a TNS relay that was a little rusty inside.

My windshield wiper problem was unrelated and just that I forgot to plug the harness back into the motor after doing the engine swap.

Thanks for posting the diagram tho - kept me from digging up my service manual.

Ernesto13B

iTrader: (4)

Im not sure if this will help or not, but I talked to Ray from Malloy Mazda a while ago and he said an easy way to find out if its your TNS relay, is if you remove that relay, and install the other blue relay right next to it because they are interchangeable. If your tail lights now work, then thats the problem, if not then you verified that relay as good.

If the tail lights share the same circuit as the glove box light, check to see if the glove box light comes on with the headlights on like it should. If the light does NOT come on, then you know the problem lies between the battery and the glove box light. If it does, then the problem is between the glove box light and the tail lights.