buj818

Ok, in the pic, you can see a 4 pin connector on the left. That goes up into the alternator. The 6 pin connector on the right shows where the neutral safety switch and 5th/rev lights wires come out of and go to their respective places. See how the B/W wire from the connector on the right comes over and mates with the shielding on the left? I dunno, but it just doesnt look right. With that being said, when the connector on the right mates up, the B/W wire terminal of the male connector is blocked. I dont mean someone did it second hand, its just solid with no place for the wire to go. Im trying to find something on it in the wiring diagram, but nothing is making sense to me. Another quick question i have is should the cooling fan come on when the key is turned to acc? I never noticed that before, but it was doing that this morning, and its not hot out at all. Please help bro, im bout to go postal. lol Thanks! Brian

RotaryRocket88

iTrader: (7)

Ok, go to page 50-114 in the wiring diagrams. There are diagrams of all the connectors on each harness. The plugs you're looking at are part of the front harness (F) or engine harness (E). The plug connection FE-02 (listed elsewhere) seems to have all the right colors for your 6-pin plug (B/W, Y/R, R/G, B, B/Y). It's one of the ones that says "to engine harness" on pg. 114, and you have the other half "to front harness" on pg. 116. But here, and anywhere else I saw this connector seems to show the B/W wire continuing on instead of being blocked off. So, I'm not sure why the plastic connector is like that. Also, that 4-pin connector should be for the CAS, not the alternator. The B/W is likely 12V power & has shielding to prevent interference with the CAS signal to the ECU.

I'll take a look in my car after work today to see if I can spot that connector. If I can, I'll see if the B/W wire does the same thing.

buj818

shoot, i had meant to say that the grey wrap with blue stripe bundle just houses wires that go up to the alternator area. both of these connectors are down below. just looks this way cuz i pulled everything up to get a better look at. i seen the fe-02 and the other diagrams that youre talkin about, and it just doesnt match up too well. thats why im really confuzzled bout this whole thing.

buj818

another thing i tried today was pulling all fuses while i had all these different things disconnected. first one i tried putting back in was the room fuse, cuz thats the one that keeps blowing on contact. and needless to say, it blew again. none of the interior bulbs burnt out. all are still in good shape. even with the body harness plugs disconnected, it still does this. id like to try to find the power wire to this fuse, and follow that to make sure its not burnt through or grounding out on something. the diagram shows me that theres a L/R wire in there somewhere. but none of the other systems involved on the room circuit are malfunctioning (warning buzzer and lights still work). ONLY the interior lights dont work. any ideas to chase this problem?

RotaryRocket88

iTrader: (7)

There must be a short somewhere along the way that's blowing the fuse. Trying to track it down won't be fun, but I'd start by unbolting the fuse box, and tracing the L/R wire as far as you can.

buj818

damn dude, that was the LAST thing i was hoping to hear. haha this is gonna be insane, i really dont even know where to start, but i dont have many options in this case. does the fsm cover removing the interior fuse box and all that? guess ill just unplug everything and start pulling nuts and bolts as i see them. any tips or concers i should be extra careful about?

Puck

iTrader: (1)

Quick way to test for a short in a wire is to use a multimeter, with a continuity "alarm". If you have a wire that is grounded, hook up the multimeter to it, set it to continuity alarm, and hook the other lead up to ground. If the wire is grounded, the alarm should sound. Now, you can start moving the wiring harness around, until the alarm stops. When the alarm stops, it helps you zero in on where the actual ground is occurring.

WonkoTheSane

iTrader: (2)

Alright.... That is screwed the hell up

If I'm reading the picture right, it looks like the person stripped the ground to the CAS (Crank Angle Sensor, the left white 4 pin connector in the picture) to the... well ???? I guess.

Generally Mazdas' engine harnesses run Black/White (B/W) as a power connector to accessory 1 circuit (from what I've noticed, anywho)...

That wire around the CAS is supposed to be a ground, connected to the ECU ground harness, and not connected to anything on the side pictured (see thread: https://www.rx7club.com/showthread.p...ght=CAS+shield ) .

My guess is that B/W wire is the ground in the switch (I cannot find the bloody 5th gear switch in the wiring diagram), and when you switch 5th gear on, you short out through the CAS's ground/shielding wire, shorting and popping the fuse.

Try cutting that once, reconnect everything and shift to 5th. We'll worry about what to connect that to after you try that.

In the mean time, may want to page Hailers (or is his handle Hailers2 now?) to the thread.. He'd be the man to ask about what that B/W is supposed to connect to!

Good luck!

RotaryRocket88

iTrader: (7)

I checked on my car a little while ago, and it's definitely not like that. My 6-pin plug has the B/W wire enter one side, and exit the other, so who knows what the hell happened to yours. The wiring diagram is the correct routing.

And as wonko said, the CAS ground should not be connected to the B/W wire. I can't tell from the picture, but is that some sort of crimp connecting them? Mazda didn't crimp anything like that.

Also, the 5th gear switch is called the "over top switch" in the diagrams. On pg. 50-25, the wire color is shown as B/L on both sides of the FE-02 connection.

WonkoTheSane

iTrader: (2)

Thanks for the clarification, RotaryRocket.. I thought the "Over top switch" might have been it, but I really didn't want to say anything because I'd rather give out no info than bad info

Looks like the backup switch gets two wires @ FE-02, a B/Y providing power from accessory 1 circuit, and a R/G wire carrying the power to the lights (through FR-02), per page 50-60.


So, FE-02 is supposed to have 5 wires in a standard transmission car:
B/L - 5th Gear ("Over Top Switch" in Japanese, apparently) wire
R/G - Output to back up lights (through FR-02 harness)
B/W
B/Y - Backup lights input 12V (from main relay harness)
Y/R

So what's the other two go to?

RotaryRocket88

iTrader: (7)

Well, I found the Y/R wire. It's for the oil pressure gauge (pg. 50-40). But the B/W wire has to be 12V power. There's a B/W wire carrying power to the interior fuse box on the engine harness (pg. 50-12), so it wouldn't make sense if this one was something entirely different.

WonkoTheSane

iTrader: (2)

Does the Oil pressure gauge show any power going through it?

Either way, I think we got the problem

buj818

Wow.. This is a beautiful thing the way ya'll jumped on this to help me out. Yes, that is a crimp holding the B/W to the shielding. So now its certain that that wire has to be discon'd from the shielding, which of course leads to my next question... where does the B/W lead go to, and should the shielding bolt onto chassis for ground? I also seen on the diagram that theres a B/W as 12v leading into interior fuse box as well... Heres another test i did while all this **** was unplugged... I checked for voltage at every individual circuit in the interior fuse box under battery power only, and all top 4 fuse links were reading constant 12.53V. Every other fuse read 0V. I forget the names of all the other ones except for the room fuse, but thery were all the ones on the top row underneath the spare row. I was told that it is too high. Again, please forgive my inability to read electrical schematics, but im learning.... slowly. Thanks again! Brian

WonkoTheSane

iTrader: (2)

Definately disconnect that. The B/W wire probably connects to the other side of the B/W wire in the wiring harness that was cut from is my guess

As for the shielding, you do NOT want to connect that to ground. It seems kind of counter intuitive, but for shielding grounds like that, you only want them connected on one side; in this case, that side is already connected down by the ECU. All you want to do is trim that down so it can't ground out against anything. On my harness, the shield is trimmed even with the edge of the outer black jacket, and it's all secured with electrical tape right up to the connector.

12.5V is a fine value to read when the car is turned off. Your battery will generally hang out around there after the car's been sitting more than a few minutes. If you ever have the car running and measure it, you should measure between 13.5ish (idle) and 14.4V (under load of any sort), that's what your alternator puts out.

The fuse test sounds about right. In the first few pages of the electrical schematic section (I don't have it in front of me, maybe 50-14 or something?), there's a diagram with your fuse block in it. If you trace that, you'll find the top row is connected to the "B" line (Battery), I think the 2nd and 3rd row is to the S1 (start 1), and the last two rows are to the S2 lines (Start 2). This means, the top should have power all the time, and the S1 rows should have it when the key is turned 1 notch, the S2 rows should have it on the 2nd notch. That was from memory, so it may not be exactly right

It sounds like you'll be a pro at reading these diagrams by the time you're done with this car

RotaryRocket88

iTrader: (7)

The Y/R wire is the ground side for the gauge that runs from the oil pressure sender.

The other half of the B/W wire is somewhere down the harness, whether it's the engine harness side or the front harness. It's time for him to start unwrapping the whole damn thing. This must be the root of the problem.

And I posted page 50-14 up on the first page of this thread too for quick reference.

buj818

Ok, check this out, i think i may be learning something here. As far as my Room fuse blowing issue.. Im looking at the wiring diagram, and it looks to me that connector fem-02 houses the Blue/Red wire that should connect to the back of that 7.5A fuse link. Am I right on that? If thats the case, would the best route for me to take off the fuse box, and try to follow that wire all the way up to the main fuse box in the engine compartment? That parts shady to me, cuz it looks like theres 1 wire on the diagram that feeds 4 other fuses as well. OR, should I work from the fem-02 connector and work my way through the interior and body harness looking for jacked up wires being that i dont have an issue with any other circuits?

RotaryRocket88

iTrader: (7)

Start on the FE-02 connector side and find the other half of the B/W wire. If you're feeling motivated, pull the fuse box and poke around, but you can always do that later when the wiring harness is back in place.

buj818

uh oh, fe-02, or fe-05? i see the 05 is a single wire B/W wire. is that the one you mean on page 50-14? NM, i see fe-02 on page 50-16. sorry bout that. I think i know where you mean now.

buj818

well, got the B/W wire all straight (i think), it was cut back about a foot into the harness. Now as far as the room fuse blowing on contact, heres what i got so far.. with the BTN 60amp fuse in the eng comartment pulled, nothing blows on me, which is good. then with the BTN fuse put back in, and with EVERY connector at the fuse box, ignition area, and cpu disconnected, the 7.5 room fuse then blows. is that telling me that the problem is between the main and interior fuse boxes? if thats the case, i cant understand how since according to the fsm on page 50-12, the R/W wire looks to power other fuses as well under battery power that are NOT blowing. any ideas?

RotaryRocket88

iTrader: (7)

If there were a short between the ROOM fuse and the BTN fuse, the BTN fuse would be blowing. The section of the interior fuse box that receives 12V power through the W/R wire wouldn't be in the circuit, so they wouldn't blow. So, the fact that it's just the ROOM fuse that keeps blowing means the problem lies with something that is receiving power through it.

Also, I just noticed that the picture I posted on page 1 is of the wrong 7.5A fuse. The one towards the top of pgs. 50-12 & 50-13 is actually the ROOM fuse, as you were assuming. The W/R wire on the engine harness is what's related, not the B/W wire (which runs to the other 7.5A fuse). Still, the fact that your B/W wire on the harness was chopped off couldn't have been a good thing.

buj818

hmmm, damn. i thought i had it narrowed down a bit. but then again, lookin at my last post, i dunno if i worded it right cuz i was in a hurry to get to work.. lemme try again, lol. i have the W/R wire so that power is going from the main fuse box to the interior fuse box. all harnesses within 3 feet of the fuse box is disconnected. so pretty much, all power is contained from the main box to the interior box. im starting to think that the issue might be within the interior fuse box itself, solely at the fusable link for the 7.5 amp room fuse. that may be why that its the only fuse that keeps blowing. watchya think?

RotaryRocket88

iTrader: (7)

If you're confident that you have everything the ROOM fuse powers unplugged, then I guess that'd be a possibility. You can test whether everything has in fact been disconnected by going down the list of items on page 50-13. If the interior lights, etc... do not work, you should have taken care of everything.

Another thing I've been hesitant to suggest is placing a slightly larger fuse in there instead of the 7.5A (maybe 10A), but I would only do this if you're 100% certain all the components fed through the fuse have been disconnected. That extra 2.5A might be enough to fry something, if there's a short.

buj818

I have been using a 15amp fuse to quickly touch to the box, being that it would light up a lil and make the blowing sound without actually blowing the fuse. but im not going to put anything of higher value in once its figured out. OH ****!!! can you copy/post page 50-13? I just noticed that 50-13 is missing from my FSM. goes from 12 to 14. haha aint that about a bitch! lol no wonder im having trouble finding certain things.

buj818

also, on page 50-12, it shows the fuse, then with a L/R wire. does that L/R wire mean that its the 12V wire that feeds all the items of that fuse? and lastly, what does the 3 with a circle around it mean thats right after it? but i really would like that page 50-13. haha

buj818

i was wrong on that B/W wire that i though was burnt. turns out it was for the single wire connector between harnesses. That single wire is now straightened out, but now i need to figure out where that wire goes thats in the picture again. both ends of the connector house the B/W wire, so i was wrong about that before too. now i just need to know what it goes to. other than that, the only other thiing that needs figured out is where the L/R wire goes from the interior fuse box. CPU? another connector? Tomorrow I am going to cut and replace the thick W/R wire from eng fuse box to the interior one and see if that helps at all. but for now, i been digging through the fsm for the L/R wire, and all i see is that its the bottom terminal of the ROOM fuse. just gotta figure where that runs to, then i can get it narrowed down and trace it from there.