IanS

iTrader: (4)

Heres the deal. With the battery hooked up and the key OFF I have power to the main relay, idiot light cluster, gauge cluster, ecu, and a few other things like turn signals. The biggest problem is when the car is running and you turn the key to off it will stay running. I am forced to yank the EGI fuse or dump the clutch to make it die. The second main problem is that if you let the car sit with the battery hooked up, it will go dead. When I turn the key to ACC the radio and other items power up like they should. When it is turned to ON the heater logicon powers up like it should.

I was originally thinking that it was a problem with the ignition switch. Maybe something is staying on somehow and that is the problem. I unplugged the ignition switch wiring and nothing changed. I am honestly at a loss as to what could power this much stuff. It almost has to be something to do with the body harness and not the engine one it seems. I could easily be wrong though.

Does anyone have any ideas on what would possibly cause these conditions? Forum member BLMCQUIG also has this exact same problem with his car.

My car: 87 TII body with S4 vert engine, 86 base body wiring, S4 TII trans, rear, etc.
BLMCQUIG's car: 87 Sport with S4 TII engine, trans, rear, etc.

Because of the differences of ECU, engine harness, and engine itself is why I am thinking that it would be something to do with the body harness and not the engine stuff. I suppose if I understood more on what relay does what and turns what on, etc I may have a decent place to start with troubleshooting.

What tells the main relay to turn on? What does it actually power up when it turns on? What relay/switch or whatever powers up the gauge cluster? What powers up the ECU? What does the ignition switch actually turn on (what is it supposed to turn on)?

These are the questions that I simply dont know the answers to (more of an FB guy). Any/all ideas welcome and appreciated.

Thanks for reading all this,

-IanS

Edit: BLMCQUIG's car did this before his TII swap. Not sure if that helps any but I figured I would give as much info as I could.

Nismo Convert86

iTrader: (7)

Sounds like a Alt wiring problem, start it up, turn the key off, and unplug the alt, if it dies well there you go. It's a fairly common problem, just can't remember the specific reason it does that...

IanS

iTrader: (4)

I can try that although from all my searching it seems to be the difference of alt wiring is the fact that the alt wiring is on the body side for NA and engine side for TII, so when you swap from NA to TII or vice versa - you end up with 2 alternator plugs.

HAILERS

So? What EM harness are you using on the engine? A turbo one or a non turbo one? An if Turbo EM harness, what changes did you make to make it work with a non turbo Front harness?

A normal car works like this. You turn the key to ON. That powers the ENGINE FUSE. The ENGINE fuse in turn powers the Main Relay up and the Circuit Opening Relay.

IF you turn the key to OFF and you still have the Main Relay pulled in, then something is backfeeding the circuit where the ENGINE fuse is. If the turbo EM harness is connected to a non turbo Front harnes, and no corrections were made to the EM harness, it's POSSIBLE your problem lies there.

Or it could lie in the way you wired the alternator. As in upside down, backwards. No way to tell from here.

See wiring diagrams.

IanS

iTrader: (4)

I am using a non turbo engine harness.

Also using NA ECU, and wiring from a 86 base for the car. I did not change the alternator wiring from how it was/is stock. Were some alternators wired backwards internally? I will check out the engine fuse and see what I can come up with.

BTW what does EM stand for?

IanS

iTrader: (4)

I went outside and started the car. I then turned the key to OFF (actually completely removed it from the slot) and then unplugged the alternator and the engine stayed running. So, I have to assume that the problem does not lie in the alternator wiring.

SpooledupRacing

faulty ignition switch..

it could be an issue.'


I know SAABS have this same problem when the electrical connectors behind the key tumbler gets eroded..

I would pull the ignition switch out and check all the wiring or hopefully just replace it with a spare.

IanS

iTrader: (4)

Thats what Nick thought also. I actually unplugged the ignition switch plug and again no change... Actually, I should say that the main relay did not click off as I did not have the engine running at the time of unplugging the ignition switch.


Another question that may or may not be related. Down by the ignition switch harness there is a 2 wire harness (both 10 gauge) - Black and a Black/White wires that are seeing 11.6x and 12.3x volts. Jusy wondering if this is supposed to be this way.

HAILERS

Simply go out to your car, pull the SMALL plug off the alternator. Start the engine. Idle it for a moment. Turn the KEY off. This takes a lot less time than writing another post.

Reading the FSM, you find that the harness that attaches to the fuel injectors is the EM harness. The EMISSIONS harness. Each wire on that harness has (EM) next to it it (in the wiring diagrams), so you know which harness your looking at in the drawings.

The E or ENGINE harness runs on the left side of the engine bay and goes to the engine bay fuse box, cables to the battery and the like. EAch wire in that harness has (E) next to it. The F or FRONT harness runs across the interior of the car where your feet are then exits the cockpit and goes fwd on the left side of the engine bay to the front of the engine bay and crosses to the right front of the engine bay. The R or REAR harness is back yonder.

Seeing as how you used the stock non turbo harness, then it could be the ignition key or the alternator wires on wrong, or a stuck Main Relay.

After doing the alternator plug removal, if that does not work, try pulling the ENGINE fuse in the interior fuse box and see what happens.

HAILERS

The pure BLACK wire comes directly from the MAIN FUSE in the engine bay. It should have 12vdc all day long and night.

The White/black should have no power on it unless the key is to ON or better (and I might add, that wire would have to be connected up for it to have voltage on a NORMAL car). You having voltage on it MEANS there is something backfeeding that wire and thereby the Main Relay and the Circuit Opening relays. PUll the ENGINE fuse to see if it goes away, but also try pulling the SMALL plug off the alternator to see if that stops the problem.

It could be something other than the alternator wiring backfeeding the black/white wire. Mabe a cutoff switch was made for the CIRCUIT OPENING relay and something went south doing that.

IanS

iTrader: (4)

By small plug I can only assume that you mean the one that is a T shape. The only other thing for the alt that COULD be considered a plug is the wire that is attached with a nut that the alt supplies power to the batt through. The T shaped plug is what I unplugged. I will try out the engine fuse in a bit.

Also my main relay does not seem to be stuck. I say this because I can hear it audibly click when I attach or detach the battery cable - wether it be positive or negative.

Also Im not trying to make it sound like I am arguing with you in any way HAILERS. Im trying to do this step by step so that I dont overlook anything. Also I want to understand why the problem happens when it is fixed. I dont want to simply band-aid it and not know what the actual problem was in the first place.

"Yeah this guy online said for me to unhook this plug. I dont know what it does but it fixed the problem." - Thats not me, and I do appreciate the help and patience.

HAILERS

First jpg shows the ENGINE harness colored BLUE. Shows the FRONT harness colored RED and shows the EM harness shown in black/white.

Second jpg shows how stuff works. See the B/W wire leaving the ignition switch, going to the left to the 15a ENGINE fuse which in turn feeds (pulls in is a better description, not feed) the MAIN relay and the Circuit Opening Relays.

The same 15a ENGINE fuse also feeds the alternators black/white wire but that is shown on another diagramn having something to do with Charging and Starting or the like.

Third jpg come out of the sorry *** 88 wiring manual, and shows the B/W wire coming to the Alternators small plug. It has (EM) next to the B/W wire as it arrives at the alternator but if you follow it up the page it has (F) next to the B/W wire indicating it is now in the FRONT harness. It made that tranistion at FEM-01 (which stands for Front to Emissions harnesses). Anyway, that same B/W wire gets fed by the ENGINE fuse shown in the other diagrams.

HAILERS

Turbo alt is shown in this jpg. See (E) next to the B/W wire at the alternator indicating it's a part of the engine harness. Goes to a 15a fuse which feeds it and that is the ENGINE fuse.

Then again, your backfeeding could be another thing backfeeding the B/W wire.

IanS

iTrader: (4)

OK so engine fuse kills engine. Also it kills the main relay and the circuit opening relay apparently. I can hear multiple relays clicking. Is the circuit opening relay in the interior? The 2nd relay is clicking from inside. So, heres the main question. Which wire is supposed to be where in the alternator T plug? With your description above it seems that something in the wiring is messed up between the engine fuse and the alt OR the alt T plug is actually wired up backwards, which honestly makes no sense but if that is whats wrong I would like to know a reason why. I have an S4 NA alt - worked just fine in my FB, so must not be the alt itself. I didnt have any backfeeding or battery draining problems in the FB. Granted it is a 12A car and may not have been wired the same as far as the car wiring goes.

If I go ahead and rewire the alt backwards from what it is now will it affect anything negatively? I suppose it shouldnt but asking to make sure. I can try that out tomorrow and update with more info then.




That pic is too small to see.

HAILERS

Uh. With the ENGINE fuse in, did you pull the alt small plug off? What happened? Gotta know to fix.

ON a stock series four, the TOP of the T is where the black/white goes. ON a stock car, you'd read approx 12v on both the black/white and the white/black, because your reading back thru the alt relay in the CPU on the white/black wire. Just FYI if your using a meter on it.

If your car has been doing fine, and no maint has been done on it, and this problem just suddenly appeared, who knows what went wrong. I wouldn't.

Circuit Opening Relay is above the steering shaft and above your knees. Yellow plug/ base, I can't quite remember.

HAILERS

What I'd do. I'd go to the alt plug. Put a meter on the black/white wire. See batt voltage. Now pull the ENGINE fuse and see if it goes away, proving that is the wire that goes on the top of the T.

Another fuse feeds the w/b wire so that voltage would stay there even if the ENGINE fuse was blown/pulled out. I forget what that fuse is. Not a player anyway.

10aeRX7

iTrader: (3)

i just finished figuring out this damn problem after 10hrs of trouble shooting.
the wire that was messed up was a black wire with single spade (male) terminal right underneath the fuse panelin the engine bay.

now i have a haltech and most of the stock stuff is out but never the less what i had to do was:

connect the black wire from vhicle harness to a seperate 80A fuse holder( car audio type) and from the fuse holder to the 80A main.

IanS

iTrader: (4)

With ENGINE fuse in and engine running I pulled out the T plug on the alt and it stayed running. I will test the alt wire and also look for the wire that Canadian dude (10aeRX7) is talking about.

As far as it suddenly appearing - I havent owned this car for very long, maybe 4 months and it has been this way since then and was also this way BEFORE the previous owner got it.

IanS

iTrader: (4)

Wait a second. How is it that by powering a wire I am able to turn off the engine, etc with the key? I guess I dont understand what you're saying. I will look around for that wire and I will play with it if this other stuff doesnt work.

HAILERS

Something is missing here. Was the key OFF when you did that. I'm guessing it was. If so, then something else is backfeeding that circuit.
Not sure what. Something downstream of the ENGINE fuse. What's downstream? Alt small plug, Main Relay, Circuit Opening Relay AND the wiring to the FUEL PUMP from the circuit opening relay. If someone has jury rigged something with the fuel pump wiring, that could be a problem.

HAILERS

There's single black wire and connector, just below the engine bay fuse box. Its purpose in life is to feed the BLACK wire on the ignition switch. You know, the connector with the black and black/white wires. I doubt that is a problem since you said you HAD batt voltage on that black wire. Supposed to.

You don't have a lack of power, you have power when it should not be there.

HAILERS

To prove it is/is not the wiring at the fuel pump, pull the circuit opening relays plug off, and see if the Main Relay still stays pulled in or not. IF pulling that, maybe it is something wired wrong at the fuel pump plug. Got me.

You don't need the engine running to check that. If the engine is idling, it's going to die from lack of fuel if you pull that plug on the circuit opening relay. But actually, it'd take three or four seconds for the lack of fuel to show up. Lack of elect would kill the engine right away.

To late in the day to think about this.

The engine will keep running if you pull that plug with the black and black/white wire. Right? Proves it's not the igniton switch imho.

IanS

iTrader: (4)

You know, mentioning fuel pump reminded me of the craptastic rig job that the previous previous previous previous (lol) owner did with their super-hot megasquirt install. I will check the other things first and work my way back but I seem to remember that the fuel pump wiring was extended and hooked back the correct way. Off to bed for now. I will be back on sometime tomorrow after I check out the circuit opening relay and dig around and make sure all the fuel pump wiring is still intact and correct (wont change anything though until I get proper say so from "the man" HAILERS).

87 t-66

iTrader: (133)

hailers

HAILERS

For SUNDAY: Since you pulled the plug off the alt, and the engine stayed running, with the key to OFF, then we need to step back an rethink this. Maybe it is the igniton switch.

IF the above is true, start and idle the engine. Pull that igniton switch plug that has the black and black/white wire. IF the engine dies and the relays relax, then I've wasted your time and effort and it most probably is the switch internally fucked up.

IF the engine stays running with the ignition switch plug with the black and black/white wires pulled off, then it's off to the races again.

I'd read the above and try it out FIRST before you do anything else. IF it turns out to be the igniton switch, I need to bow down to Spooledupracing. It's just that we've had a number of miswired alt plugs backfeeding on this forum.

This could be another of my boners. Like telling someone how to miswire a starter solenoid. Duh, I goofed that one up pretty bad plus I saw where I had written on a thread that the speed signal to the cruise came from the trail coil. Eeek, I know better than that.