Mouse2k4

So I recently did the 130 amp taurus alternator mod documented step by step and I realized I had a wire wrong and I drove on it and after about 45 minutes of driving I paid the price.... I had the I wire connected to the W/B wire as opposed to the B/W wire it was supposed to be connected to... Okay so while I was driving the car was running in peak performance yada yada and all of the sudden my wipers are wiping as fast as they can and the heater just starts blasting heat even though its turned off and I lose my tach and the car dies out. I put on my hazards and moved into a close parking lot. Turns out the "main fuse(80A)" blew. Okay so today I went back to where I left the car, replaced the fuse, redid the wiring the correct way this time... and the car cranks but doesnt come on. I get my idiot lights when I turn the key and my headlights work and my heater works fine and my wipers work as intended and all that. Now I suspect the main relay is my problem because I can jumper the 4 pin connector with the ignition on and I hear all the relays click except the main of course but when I plugged it into the main relay I have nothing. I checked the wires in the 2 pin connector and was recieving no power at all. Im not sure how to get power to these wires but even with the 4 pin connector jumpered the car still wouldnt come on. I got spark after jumpering it but still no win.... Opened up the main relay to take a look and everythings still shiny and looks like it should still work(no loose parts).

Also note that every single fuse is good now.



Sorry for the TLDR but I need suggestions. Thank you.




Reference:
https://www.rx7club.com/2nd-generati...1060424/page3/

satch

iTrader: (1)

The engine fuse powers the B/W wire in the two wire plug of the main relay. If you jumpered the 4 wires in the 4 wire relay plug you should have voltage on the B/Y and B/W wire in that plug. Do you?

Mouse2k4

yes I do.

satch

iTrader: (1)

If you don't have voltage at the B/W wire in the 2 wire main relay plug that points to the engine fuse being blown as already stated. The 15 amp engine fuse powers the circuit opening relay which powers the fuel pump so if this fuse is bad then you could not have fuel. No fuel equals no start.

Mouse2k4

Where is the Circuit opening relay located in the S4? Im not sure its the fuse itself but maybe the integrity of the wiring. Will have to take another look at it tomorrow. Oh and also Im not getting even the littlest bit of a jump from the tach needle... nothing... Same idea? idk?

satch

iTrader: (1)

The relay is located to the right of the steering column just underneath the dash. The top row far left wire (B/W) should have voltage w/key to start. If it doesn't then you're not getting fuel.

Meter fuse powers the gauges so check it.

Mouse2k4

I am getting my fuel level gauge so I believe the gauges have power to that. Now if the B/W wire of that relay isnt getting power where does that one get power from?

I still have to get to the car to test some more things but its raining and lightning out and its about 15 minute drive away but knowing more is better.

satch

iTrader: (1)

The engine fuse.

Mouse2k4

okay so the 15A engine fuse controls both the main relay, which in turn controls the coils amongst other things for my spark, as well as the circuit opening relay, which controls the fuel system? So if the 15A fuse is fine but not receiving any power then what?

satch

iTrader: (1)

Could you clarify what is not receiving power?

Mouse2k4

well actually now that I think about it, if the fuse box doesnt get power then I would have nothing at all so scratch that question.

Mouse2k4

Okay so I got the car running... it was the 15A engine fuse. I went through all the other fuses and replaced any that were blown or looked old and I still have a rough idle and I lost my Tachometer as well as my cigar lighter and my logicon...



Also note brand new spark plug wires because I broke one.

Mouse2k4

So I still dont know why my spark is weak. Logicon still doesnt work but the cigar lighter wasnt working because the butthole that owned the car before me put a 20A fuse in instead of a 10A and it instead took out the fuse that was in the phone charger that was in the cigar lighter... so cigar works.

Tried jumpering the leading coil to the trailing coil and couldnt get a whole lot of reaction from the tachometer but theres a little reaction there... (jumps a millimeter)


I did touch a ground on the engine but im not sure it would effect it like this

barkz

iTrader: (1)

Bad grounds could be no tach signal, no tach, no start

satch

iTrader: (1)

Why do you believe your spark is weak? Is it because your tach is problematic.

Mouse2k4

I believe spark is weak because it has a rough idle and the tachometer seems to try a little if I push the throttle a bit.

satch

iTrader: (1)

The tach could have a poor connection on the back of it or it could just be the tach. The engine should run just fine using the lead coil alone. You could sand down the fender where the coil brackets mate w/the fender. You could also measure the check connector at the trailing coil w/key to on and it should read close to .6 volts. And of course the spark plugs and plug wires need to be in proper shape along w/being connected to the correct spots on the engine. You could also unplug the trailing coil and replug it after cleaning. And the engine grounds need to be up to par. And specifically how is the idle rough?

barkz

iTrader: (1)

Not questioning your greatness satch, but why would it run fine with only the leading coil? We're not talking injectors here. At idle both coils should be firing, no? I feel if the trailing was not up to par the tach and idle would suffer.

satch

iTrader: (1)

The tach would not work w/o the trailing but the trailing coils job as far as running the engine is to clean up any unburnt fuel left over by the leading coil and is thus used for emissions purposes. Many people on this board have run their cars using only the lead coil (for diagnostic purposes only) and when idling it should run no differently then if both coils were connected (this assumes the car idled properly before the trailing coil was unplugged). If you ran the car only using the trailing coil it would always run rough.

Mouse2k4

replaced the trailing coils with another I had and still no tach... I have a tach from an s5 automatic.... is it worth or even possible to swap it to see if its the tach itself?

satch

iTrader: (1)

Not familiar exactly w/how the tach is wired in the cluster but chances are there three wires connected to it. A voltage wire, a ground wire, and a input signal wire. You can use the check connector near the trailing coil for the signal wire and also provide a voltage and ground to the tach and you could check it w/o having to install it. And speaking of the check connector, what was the voltage on it w/key to on?

Mouse2k4

The trailing test wire is like .4 volts and the leading is like 12.5

satch

iTrader: (1)

Did you reground the trailing coil bracket? What is the altenrator output voltage as measured at the alternator while the car is running?

Mouse2k4

I cleaned all the grounds yeah and all the contacts to the walls. Alternator voltage ill have to get back to you... Car seems to run fine now btw no rough idle after I fixed a boost leak but still no tach so I think its just shot as part of the cluster. will check the alternator output voltage tomorrow. B post is output right?

satch

iTrader: (1)

Yes.