rx7fresh

Hi guys how are ya ? Ok so i was taking of my stereo and the wires touched , my turn signals, taillights and driving lights not working, no interior lights no clock, i checked the fuses all good exceot stereo i changed but i noticed in the fuse that says room a 7.5 had a 20 in it from previous owner, what could have burned out? Whats that lil metal box under dash is it somethng i can replace or is it in my wiring? What dies the room fuse(7.5)control any help will iireally be appreciated

rx7fresh

I bught a haynes manual and saw a diagram in it it shows it goes to all the stuff i said is malfunctiomlnng im still. Cnfused where do i start whats gong on?

drvid

This happened to me I had to drive home with no rear signals/brake or interior lights!
I would suggest you check and replace all fuses in the interior panel and make sure they are all the correct rating according to the panel cover diagram.

satch

iTrader: (1)

Make sure the Illumination fuse is good as well as the Turn fuse and the Hazard fuse even though you checked them once already. By having a 20 amp fuse in place when a 7.5 amp was called for could have damaged the wiring.

rx7fresh

Well i changed my fuses and nothing whats the next thing i should check? Could it be the fuse box? Or wiring? Does the whole harness burn or just a spot? I alread miss driving my 7

midnightbluefc

iTrader: (19)

if all fuses are in tact, remove your cluster and check your headlight switch and the harness going to it i have a feeling that the switch went bad and theres a white/green wire that might be burned if so, youll need a new switch and harness

rx7fresh

Ok so if it was tyat would it affect my blinkers running lighrs brake lights and taillights?

satch

iTrader: (1)

Sure the brake lights don't work? If they do not work then check the Stop Light Switch at the brake pedal that has two wires. One wire is Green/White while the other wire is White/Green.
The Green/White wire should have constant voltage (no key). Does it? The White/Green wire will have voltage w/the brake pedal depressed. Does it? If they both do then go to the rear of the car and gain access to the rear of one of the light housings and locate a plug that has spots for six wires but only has five wires to the plug. One of the wires is solid Green. When the brake pedal is depressed this Green wire should have voltage. If it does and the brake light does not come on then the bulb is the likely culprit or the ground for that circuit.

bbreidhaupt

i'm not to familiar with the wiring on these cars. but i would check the diagrams for a fusable link that may have failed. if there is no fusible link try unplugging the main connector from the parking lights and turn signals from under the hood, then unhook the ground cable on the battery. take a test meter and ohm the ground side of the light. if you get a open loop reading (OL) or if it has a high resistance you have ground issues. you can also check to see if you are getting power at the switch. test your relay if there is one. and if all else fails look at the wiring diagram and see if another system is tied in. stranger things have happened, i've seen ac systems tied into the o2 sensors wiring before.

rx7fresh

Thanks for the help this started happening when the 7.5 fuse should burned out but since it had a 20 something went really bad! What is this meter i need to buy how much is it? Thanks for the help guys

bbreidhaupt

just about any multi meter will work. you can pick a craftsman at sears for about $30. if you want a really good brand meter like fluke then it's gonna run about $150. my craftsman has never let me down though.

satch

iTrader: (1)

Home Depot or something similar would run you no more than $15.

bbreidhaupt

you could borrow one from your local parts store aswell. just tell them you need a multi meter, you put a deposit down on it, and when you are done take it back and they refund your deposit. or you can keep it and they keep your deposit. the deposit is usually the cost of the tool and they usually bank on you keeping it so they make a sale. everyone should have a meter, its one of the handiest things you can have.

rx7fresh

Nice thanks guys soon as iget back to albq(im in dallas) ima give it a look with my nee multimeter!

Akagis_white_comet

iTrader: (4)

A multimeter, preferably digital, is one of the Requisite tools that every owner should purchase immediately. Even if it's just a $5 one from Harbor Freight, it earns its weight in gold the first time you need it. I have 3, one near my computer, one in my shop space and one in the car at all times. Even after setting one on fire by attempting to measure current draw on my starter, it still works! That one just can't measure current draw anymore

Just so we understand this correctly, I'm going to recap the events: During stereo removal, two or more wires touched together, resulting in the loss of the following functions: turn signals, taillights, driving lights, interior lights and clock.

This is a short, and should immediately blow the fuse. The Room fuse is rated at 7.5A to ensure it blows before the wiring is overloaded.

Before you do anything, visit the FAQ and download the Factory Service Manual here: https://www.rx7club.com/2nd-generati...faq-fc-494667/
Also found here are pictures of the fuse box covers with the proper ratings for each fuse.

86-88 and 89-91 wiring IS different and referring to the incorrect diagram will leave you very confused when the connectors don't match. For quick reference, S4 cars have FOUR stereo connectors while S5 ones have TWO.

By this evidence and the 20A fuse in place of the correct 7.5A one in the Room Fuse socket, I'm going to assume that a previous owner cheaped out and butchered the stereo wiring to save $10 and overloaded the circuit (Worst Case Scenario). It your car does indeed have bare wires as a result of removing such hackjobbery, the first thing I would do is fix this wiring mess properly using a stereo repair harness. For Series 4 cars (86-88), it is Scosche# MA01RB. Series 5 cars (89-91) use Scosche# MA02RB. These are available from other sources as well, but having the Scosche part number makes it easier to ensure you receive the correct part.

If the wiring looks okay, with no visible damage and one or two terminals in the stereo connectors pulled out of the connector housing, they can be slid right back in. They will lock into place with an audible 'click'.

If the wiring is hacked up or damaged, it will need to be repaired with the aforementioned Scosche harness. Since the stereo cavity is a rather difficult area to solder in, using crimp butt splices is acceptable as long as you seal the joint from moisture. The way I do splices in this manner is to get the normal vinyl covered butt splices, then cut the red/blue/yellow vinyl insulation off in favor of heat shrink. I would highly recommend using Adhesive-lined Heat Shrink for reliability.

rx7fresh

Akagi white comet you nailes it the stereo harness was butchered by this a hole dumbasz previous owner, in the haynes manual i bought i found tye right wiring diavram for my na s4 prob is i cant understand how it works its all too outa pproportion any info on how to read a diagram sorry guyas im not auto tech just a guy very much in love with his car

Akagis_white_comet

iTrader: (4)

What I noticed in my early days as a S4 owner is that the Haynes manual has a few errors in it. My first mod was a new stereo, and I followed the wiring information found here: The Install Doctor - The Do-It-Yourself Car Stereo Installation Resource - Quick Wiring Section - Radio and Stereo Wire Colors

As soon as I turned it on the first time, there was no sound. The Haynes manual completely glossed over my 1987 GXL's factory amplifiers found on the passenger side of the dashboard and in each rear strut tower. The solution was to use the stereo's Antenna 12v output and wire that to the Amplifier's Turn-On signal terminal. For this reason, I am skeptical of the Haynes manual's accuracy and always recommend the official Mazda FSM found in the Second Generation FAQ.

The Mazda FSM and its wiring diagrams are organized very well and is reasonably easy to understand. Power comes from the top of the page, Grounds are at the bottom and every connection has a name for easy identification. Power is organized into 5 different sources:

A: Accessory Power, active when the key is in the "ACC" position and "ON" position
2: Key-On Circuit #2, active when the key is in the "ON" position, but not in "Start"
1: Key-On Circuit #1, active with Key in the "ON" and "Start" Positions
S: Start, only active when the key is at "Start". Used for the Starter only.
B: Battery, always active

Now, back to the stereo:
The stereo wiring diagram is on Page 50-96. It includes the optional Door Woofer Speakers, but we can ignore those for isolate your issues.

Battery Power comes from the single-terminal connector named I-05
I-06 contains 3 terminals, Ignition-switched Power (from the Accessory designation), Illumination (from the dimmer switch) and the Antenna activation signal (raise power antenna when stereo is on)
I-07 is a WHITE 4-pin square connector and houses the front speakers' wiring
The BLUE 4-pin square connector goes to the rear speakers' wiring. Strangely, this connector is not mentioned or named in the FSM. For this reason, follow the guide on Install Doctor to the letter.

You may need to do a continuity test to determine which wires go to the rear speakers. To do this, set your meter to Ohms on the lowest scale it can read (usually 200 Ohms) and connect one probe to the wire in question. The other probe will be connected to the rear speaker connector. If you see infinite ohms of resistance (1 _ _ _ on the meter LCD), there is no connection between where the two probes are. A good connection reads around 0.07 ohms. When you see this, look at where the probe is in the rear speaker connector. This will tell you what the wire's function is. The top terminal (when connector is viewed like the letter "T") is the speaker NEGATIVE, bottom pin is POSITIVE.

Label each wire you identify with its function in this manner.

Something you may notice in the FSM is that the original stereo has no ground. I believe this is because it was grounded to its case, which is bolted into the car's sheetmetal. A suitable location for an aftermarket stereo's ground is the 10mm bolt behind the kick panel close to your right knee when sitting in the driver's seat.

rx7fresh

Hmm ive been searching thru the site could my headlight swit h be the one that burned out? Since my 7.5 fuse was not there and in its place was a 20

Akagis_white_comet

iTrader: (4)

It is possible, but doesn't seem likely at the moment. If your headlight switch was damaged, there would be visible signs such as charred connector plastic.

The headlight switch also powers several other items such as the sidemarker lights, gauge backlights and the storage bin lights. The Red/Green wire is the output from the headlight switch for variable items like the gauge backlights, while the Red/Blue wire is the constant output. Power for all of this comes from Fused Circuit #9 (15 amp fuse in the dashboard panel) through the White/Green wire and is traced back to a 60A underhood fuse with a White/Red wire (I think the BTN fuse, not 100% sure tho). This information is located on Page 50-50 of the S4 Wiring Diagram.

Remember my previous post in this thread about doing a Continuity Test? You'll need to do one from the 60A underhood fuse to the 15A fuse in the dashboard panel. Then do another test for continuity between the 15A fuse and headlight switch. Last, test for continuity on the switch's outputs and items like the stereo illumination (variable) and storage bin lights (constant)

You can also test your headlight switch this way too.

rx7fresh

Hmm well the headlight switch sounds hopefully like the culprit to my prob i have no backlight to gauges, no cloc, no turnsignals,no tailights no brake lights no side markers, no clock no bin lights so do you think mr white commet that thats my prob i dont have a atereo in it right now my main focus is the lighting issue because i cant drive my car, where do i connect the voltmeter to wgere the fuse goes right?

rx7fresh

I bought a continuity tester and a volmeter so im ready!!how do i go about hunting down my prob how do i use the multimeter sorry never used one, do i probe where the 7.5 fuse marked room goes or in the connecters of the headlight swit h?

rx7fresh

Iactyally i got a multimeter will this do the trick?

midnightbluefc

iTrader: (19)

did u pop the cluster surround off and check the plug that going to the switch? check that and then start checking every socket on the car. the tailights, front turn signals sidemarkers, all the exterior lighting. i had a back short in the car when i first bought it. it was a beach car so all the wiring had corroding , well any exposed wiring. i got a wire brush and some steel wool and took off all the rust and corrosion that had accumulated on the light bulb sockets throught its 24+ years at the beach. some sockets i replaced and soldered in new plugs. after a good days work and dialectric grease, my 7.5A would not pop anymore. there was too much draw the corrosion was the issue. replace the switch and harness from the junk yard. no issues since.

midnightbluefc

iTrader: (19)

1,000th post for the WIN!

rx7fresh

Im gonna remove the cluster heard i have to remove steering wheel, whill it justcome off when i take off the nut or do ineed an extractor?