adamalexander

Ok, so here is my newest problem. My taillights, brake lights, turn signals, fuel guage, radio, security system and interior lights aren't working. I noticed it after trying to install a new radio. I was having a couple little problems with it and it wouldn't work so i took it up to curcuit city, where i got the radio and tried to cash in my free installation deal, they wouldn't do it but he ran a test to see if i had enough power going to it and it didn't. He suggested a fuse. I went back home and tested a few fuses that could have been related. While testing, i noticed my taillights were out and all of the othere stuff that i mentioned above (with all of the fuses in and functional as far as i could tell). They were working last night when i drove back from work (AFTER i tried to install the radio) and all of the lights were working. The only other thing that happened recently that could be related is last night i set off the security system and after deactivating it i noticed that it didn't seem to be on (the light wasn't flashing or on at all). The lights and all were working at this point though. The other thing that gets me is that the headlights and the back-upp lights both work great. The car is an '88 non-turbo model. Also, i can't see the switches doing it because the headlights work and the headlight and turn signal switches seem to be sperate from eachother. Any help is greatly appreciated as to i can't drive the car without the brake lights especally.

Amur_

http://www.johnr.com/rx7faq/faq3.html

Read the first article - this should fix it.

Icemark

Whats the red/black behind the radio hooked up too???

Sounds like when you installed the radio, you may have grounded that wire???

Do you have a blown parking light fuse (underhood 30A and drivers kick fuse box 7.5 amp).

And I am not sure what Amur posted... the first article he mentions is about colder solder joints in the CPU which would have nothing to do with your described problem at all.

It may also be the light switch which has been known to fail, but the fact that this happened when you installed the radio leads me to think more of a wiring error.

enzo250

I agree with icemark...

I think you blew a fuse while installing the radio.. Very common thing. all the things you mentioned that are not working usually share the same fuse.

adamalexander

I have checked the CPU and all seems normal. When I turn the turn signals on, you can hear the relay clicking, so I think everything is fine there. The problem is the lights do not flash ( front, back or instrument panel turn signal indicator lights ). The headlights work fine, as well as the motors for the lamps (up and down) but the marker lights (front, back sides), parking lights and brake lights as well as the dash lights do not work. The interior lights no longer work either There is nothing hooked up to the radio wires at this time, and when I put a voltmeter to them, there is no power to any of them. Also, the alarm system does not operate any more. I can arm the system (lock all the doors and hood and hatch), unlock the passenger door with the key (which used to set off the alarm) and nothing happens. Also, the indicator light on the console no longer works. I am at a complete loss on this. Any suggestions are welcome.

adamalexander

Believe me, I have checked all fuses and power to the hot side of each fuse in the box with a meter. I have checked all fuses they are all good. I have checked all fused underhood, and they are good. I can find no loose or worn wires anywhere. The bulbs are good. I just no longer have power going to them. I have taken the CPU out, checked all solder points as well as cleanliness of all solder trails on the circuit board and everything looks good. ONE THING THAT I HAVE NOT CHECKED is the ELECTRONIC CONTROL SWITCH shown in the schematic. Does anyone know where this is located and what it does?????? Thanks again for any help you can give me.

Amur_

Oops.

Where's HAILERS?

Icemark

Again the CPU has nothing to do with the lights except the actual turn signals and warning buzzer.

Again what did you hook the red/black up to behind the radio???

adamalexander

Icemark, I do not have anything hooked up to any of the radio wires at this time. They are all just laying there with the radio removed. I did, however, put a multimeter to each connection of all of the wires associated with the radio, and there was no power to any of them. I checked the fuses and everything is fine. The fuse is fine and there is power going to the hot side of the fuse box. Any ideas. Also, do you know what the "Electronic Control Switch" is or what it does? Also, where is it? Thanks for all of your help.

Amur_

Have you checked for shorts? Pull the fuse and connect your multimeter/test light. There should be no voltage. Now give the relevent harness a shake. Move it around. If there's voltage, you've got a short. You can perform this test on switches as well as fuse terminals.

Quote:

ONE THING THAT I HAVE NOT CHECKED is the ELECTRONIC CONTROL SWITCH shown in the schematic. Does anyone know where this is located and what it does??????

Which schematic?

And I'd like half take back my . When you pulled the CPU you would have found 3 circuit boards, 2 small and 1 big one. The small one with 4 prongs is the brake light warning relay and the other one is the turn signal and hazard warning unit (finally went and looked this up as I was certain that the CPU played a role with at least some of the sys you're having probs with.) While they may not be the cause of your difficulties, I believe that it was worth checking them.

Gotta wonder what the common factor among all these conked-out sys is... ?

adamalexander

Amur, The schematic that I was looking at was the "Tail, parking and side marker, license plate, storage box and glove box light system wiring diagram" in theHaynes 1986 thru 1991 Automotive Repair Manual. (Page 293). I was trying to trace something that would be in common and this schematic seemed to be the best that I could find. However, I am not sure what the Electronic Control Switch is or what it does, or where it may be located.

Amur_

Page 269 has pics and labels (sorta) for the CPU innards.

I don't know what that ECS is supposed to be.

I'm looking at 293... If I was going to use a diagram as a guide, I'd say this would be the best choice.

I'd suggest pulling the clock and checking its insides. It's part of this circuit and might be the culprit...

Icemark

Okay... you must stop barking up the wrong tree.

The CPU will have nothing to do with it as will not the clock or anything else you mentioned. AGAIN THE CPU ONLY CONTROLS THE TURN SIGNALS AND WARNING BUZZER. You are wasting your time even looking at it. Likewise you are wasting your time looking at the ECS and the clock.

If you are stuck on looking at that manual, look at the arrows. The current is coming in from the switch and going to the electronic control switch, the radio, the CPU, the clock, and all the lights.

So, if you are truely convinced that the fuses are good (which I personally doubt) then the next step is too look at the wires coming from the light switch itself.

The White/green coming into the back of the switch should have 12Volts+ on it at all times. If it does not then you have a blown BTN fuse under the hood or a blown tail fuse in the drivers kick panel.

When you turn the switch on, the red/black and red/green should both have voltage on them. The red/black should have the same voltage as the white/green and the red/green should change voltage based on the dimmer position.

If the switch tests out, but you are still not getting 12 volts on the red/black wires in the car, then you can start worrying and will need to check the actaul harnesses.

But stop wasting your time with the CPU unless your only problem is with only the turn signals.

Icemark

I am sorry, this is just plain bogus info, just like the ECS, the clock has nothing to do what so ever with the lights, other than there is a light bulb or sense circuit in it.

HAILERS

87LIGHTING SCHEMATIC:

HAILERS

BHUGHK

SureShot

OK - the fuses may be good, but do they have power from the main fuse upstream?

HAILERS

MEANT TO SEND FIRST It really does sound more like the 60amp BTN fuse in the engine bay has gone.

adamalexander

I want to thank you all for all of your responses. The car is now fixed and all items are again operational. The problem was in the fuse, but not whether or not it was good as I was checking for, but that a friend of mine came over and moved one of the 30 amp fuses under the hood to the wrong location. The spot that the fuse belonged in was left empty. If it had not been for your suggestions I would have never found it. I was checking for voltage with a test light in this fuse box when I discovered (quite by accident) that the missing fuse had voltage going to the hot side. With voltage there, it had to be used for something, so I put a fuse in, and sure enough, that was the problem.
I feel quite embarresed to have called on all of you (and you are all a terrific bunch for all of your help) for such a simple problem. I have guarenteed my friend that he will never come close to another car of mine for any reason.
Thanks once more for all of your help.