MortarArmy

Tonight I went to investigate why my hazards, radio, interior lights, ect wouldnt work.

I found the hazard fuse blown, replaced it, and presto everything worked.

Then, i turned the headlights on, and pop, the fuse went again...

So, i turned the lights off, tried another fuse, and when I went to plug it it, it sparked a little and blew immediately. For testing, i tried bridging the terminals with a 12ga piece of wire, and it heated up within seconds.


So far, Ive disconnected the hazard switch, the dome light and the power antenna. Still the same issue.

Im terrible with reading electrical schematics, so if there's something common to look for, im all ears.

blackdeath647

iTrader: (2)

definitely a bad ground, and since it first happened when you switched your lights on, look through that first.

MortarArmy

Got it fixed.

Went through the entire car and disconnected anything that relied on that fuse to operate. Got down to the VERY LAST thing, the illumination ring around the ignition.

Unplugged that, everything works great.

5hrs to get factory radio bliss

MortarArmy

Ok, well I thought it was fixed. Blew out again today. Back to square one.


Can someone tell me if the stock amps can be hooked up to a different power source? Which wires would it be? Also, is there another way to get constant 12v to the radio/clock?

Just trying to get it working, I have no idea where else the short could be.

74RX4

iTrader: (10)

That fuse supplies power to the Blue/yellow (Ly) wires. Every Ly wire in the car, with one exception, is constant 12v at all times through that fuse. These wires connect to the audio system, hazzard switch, interior lights, reminder buzzers, cylinder lights and clock.

Open your copy of the wiring diagram and follow along please.....

I'd check audio system first. Section J in the wiring diagram. Plugs J-1, 2, 4, 5, 7, and 8, all have this Ly wire. In this section is also the exception to the always 12v rule. The front RH speakers are connected to the audio system with Blue/yellow and Blue/green wires. The Ly wires in plugs J-9 and J-10 are for the speaker not 12V.

Find the Ly wires in J-4 and J-5 behind the radio. If they are ok, check J-2 inside the rear hatch near the RH tail light. If aftermarket power ant is hooked up wrong ....

If you still haven't found it check...
J-7 and J-8 for amps under storage bins
J-1 for PA relay under dash left of column

MortarArmy

^thanks.

I have already disconnected the dome lights, the rear hatch light, the radio, both amps, the power antenna, the cylinder light, the clock, the hazard switch, the defroster, the rear wiper and the buzzer. Is there anything else that Im missing?

Also, what does the PA relay do?

74RX4

iTrader: (10)

CPU, door lock cylinder light, ignition key reminder switch, lights reminder buzzer (section H) and the main buzzer on the meter panel (section C). Hatch release, gas door release are on another fuse as are the rear wiper and defroster, so these probably are not the problem. The Ly wires are a good source to tap for continuous 12v. I'd check the wires between the plugs to be sure that someone hasn't done this and not taped it properly. Behind the radio and near the fuse block are favorite places. You are talking about the 2nd fuse back (towards front of car) on the left side (sitting in the car) of the fuse block, right.

74RX4

iTrader: (10)

hmmm Good question about the PA relay. I see I was wrong in the previous post. The Ly wire in J-01 with the other end in J-02 is another Ly wire that does not have constant 12v. The wire simply goes from the relay plug J-01 to the PA plug J-02. Depending upon the position of the PA it may have 12v or be grounded, but it gets it's power from the relay, not the problem fuse. Those 2 plugs shouldn't be the problem either.

Here is a page from Jim Rothe's site with some good info about the PA and relay among other things.
http://www.jimrothe.com/mazda/#Tips

MortarArmy

Yea, that is the one.

I pulled the lower dash, pulled the fuse panel, pulled the radio out, and found nothing of suspect. everything looks untouched.

Am I right to think that the l/y coming off the fuse panel is grounded somewhere? Its probably not the w/r at the panel that is the problem? The w/r wire is supposed to have constant voltage? Is it not controlled by relay?

74RX4

iTrader: (10)

Yes. Somewhere a Ly wire is being grounded. The large gauge Wr wire comes direct from the main fusible link. If it had a problem the link would blow. It is the power supply for much of the electrical system.

MortarArmy

well, guess that means i need to pull the seats and the carpet up and start digging around there.

74RX4

iTrader: (10)

The Ly wire in the stereo harness runs under the seat from the center console to the left storage bin area, so that's a possibility. Did you find the CPU right behind the fuse box? It's a 5" X 3" X 2" black box with a 17 pin plug bolted to a bracket next to the clutch pedal arm. Ly wire is in that plug.

ls2toy

iTrader: (3)

did you ever find out what the problem was? i'm having the same problem as you, i dont have the cpu where the clutch pedal is, but my signals have worked without it before. the signal will blink 2 or 3 times and then the fuse will blow, the hazards wont even turn on at all, what was the problem if you figured it out?

etizz

i'm having a similar problem, randomly too because my wiring problem was solved but now its back again, my issue is with the radio hooked up (aftermarket) the hazard fuse slot will spark as i try to put the fuse in, but without it hooked up i can plug it in no problem, how is that possible?

edit: and i found that the cigarette fuse blows when i turn the key on

ls2toy

iTrader: (3)

you have something grounded between the deck and cig lighter ( maybe you hooked up the dimmer or light to it) or check inside your cigarette lighter to see if anythings stuck and grounding in there, there's only 3 wires for your cigarette lighter, follow them and you'll find it, should be easy. goodluck!

etizz

found it, apparently my cigarette lighter was for show and the hot wire was grounding out