sharingan 19

iTrader: (16)

You sir have missed the point...
The coil is grounded on one side (pin 85) and energized by the thick G/B wire on the other (pin 86). The battery doesnt energize the relay "24/7" because the battery is connected to pin 30, which only connects to the starter solenoid wire (pin 87) when the coil is energized.....a condition that can only occur when the thick G/B wire sees voltage.

The thin G/B is CONSTANT 12v.....if connected to the coil the starter will run constantly (like you suggested). The only way it could be used to trigger the relay is if they're was a ground triggered by the ignition, you know any?

THE PROBLEM IS THAT THE RELAY DOES NOT OPEN AFTER STARTUP.

The G/B trigger wire maintains 5v w/ key on preventing the relay from opening and cutting power to the starter

satch

iTrader: (1)

The thin B/G wire is powered by the 10 amp Power Steering fuse as stated in the FSM wiring diagram, if it is wrong then it looks like I will be running out of apologies. Pull that fuse and there is no power. It should not be constant power. Secondly, as suggested, disconnect the Interlock Switch and w/key to on check for voltage on the thick B/G wire especially if you have ABS.

""Here's a list of all of the S4's fuses and what systems they protect. S5's are mostly similar but there are a few differences. Note that most fuses protect several systems and some systems are protected by more than one fuse.""

Engine bay fuse box
RETRACTOR: Headlight retractor motors
HEAD: Headlights
EGI INJ: Fuel injectors, ignition coils
EGI COMP: EFI system
ABS: ABS system
MAIN: Alternator, Interior fuse box
BTN: Interior fuse box

Interior fuse box
From MAIN fuse
DEFOG: Rear defroster
HEATER: Interior fan

From MAIN fuse via ignition switch
CIGAR: Cigarette lighter, A/C compressor, mirrors, clock, HVAC
AUDIO: Stereo, antenna relay
ENGINE: Main relay, fuel pump, alternator, torque converter lock-up
METER: Gauges, alternator warning, cooling fan control, cruise control, reverse lights, HVAC, warning lights, reminders, AAS, alarm, 4AT control
POWER ST: Power steering, rear defrost relay, antenna relay, starter cut relayPOWER WIND: Power windows, AAS actuators
TURN: Turn indicators, rear defrost switch
REAR WIPER: Rear wiper
WIPER: Front wipers
SOFT TOP: Convertible roof
COOLING FAN: Electric radiator fan
SUNROOF: Sunroof, AAS, ABS

From BTN fuse
HAZARD: Hazard lights
ANTENNA: Antenna, power lock
ROOM: Clock, stereo, interior lights, alarm, ECU
STOP: Brake lights, horn
ILLUM: Taillights, illumination, HVAC
ABS: ABS system
__________________
Jason
'88 Turbo Convertible (Japanese import) click for pics
__________________________________________________ __

As far as the Power Steering fuse is concerned it states it powers the Starter Cut Relay and it does so via the thin B/G wire.

sharingan 19

iTrader: (16)

Now we're gettin somewhere!

By "constant on" I mean it is 12v w/ key on, so for the purpose of using it as a trigger for the relay it might as well be treated as such.

I will try out disconnecting the interlock switch tomorrow and see what that does. I did have ABS but I removed the pump as well as the ABS computer. How does ABS affect the interlock switch?

satch

iTrader: (1)

ABS doesn't affect the thick B/G wire leaving the Interlock Switch, but it is the Blower motor that does. If you have a turbo w/ABS then the blower motor taps into the thick B/G wire (after Interlock Switch but before the relay, while turbos w/o ABS the blower motor taps into the B/W wire that runs to the starter. So in your case the thick B/G wire is the one that the blower taps into and could be possibly causing the 5 volt reading you are confronted with. So, to review this point, whether the car has ABS or not dictates which wire the blower motor taps in to (ABS=thick B/G wire and no ABS=B/W wire).

Wiring diagram below illustrates my point.



Also, take heed to the LG/Y wire coming from the alarm unit. When the alarm is activated the wire has a ground on it which w/key to on and the relay coil becomes excited and "pulls" open the relay contact from passing the voltage on the thick B/G wire to the B/W wire. When the alarm is not activated this wire has voltage on it so the coil is not excited and it causes the relay contact to stay in the closed position thus allowing any voltage present to pass onto the B/W wire. This is the "switchable ground" you asked earlier as far as if such a wire existed.

satch

iTrader: (1)

I noticed in one of your posts you stated the following,

Pin 85: grounded on the driver shock tower

Pin 86: thick G/B wire (interlock/ignition switch wire)

Pin 30: 12v batt wire w/ 30amp online fuse

Pin 87: B/W wire (starter solenoid wire)
_________________________________

Looking at "Rotary Rocket's" diagram he has pin #86 as the ground. I'm guessing the above statement was a typo as the embolded pins would be the opposite as stated above.

sharingan 19

iTrader: (16)

Excellent info! So it seems the problem is this damn blower motor. If only there was a way to have it tap into a different wire instead.

Technically the alarm wire is "switchable" However specifically asked if there was an "ignition triggered ground" the alarm write is triggered by the alarm, not the ignition. Additionally, since
A) the alarm relay is ***-backwards ... and
B) it remains in the same state while the key us in the "on" position, its not going to be very helpful as a relay trigger either way.

So it looks like I'm screwed, thanks to the genius engineers @ mazda. The ONLY wire that switches to 12v is the thick G/B and its contaminated by the blower motor and screws w/the relay. I could follow karack's suggestion and write a relay off the starter solenoid power wire below the car B/Y...but if rather not add electronics to such a hostile environment, plus I don't wasn't to have to run yet another wire all the way from the battery. These cars are electrical nightmares ...fml

It doesn't really matter, 86 or 87 as long as one is ground and the other is 12v the relay will close. It might be a typo, as I didn't really look to see which was which...but that's cuz it doesn't matter, lol.

satch

iTrader: (1)

So if you pull the Meter fuse does the 5 volts found on the thick B/G wire disappear w/key to on? If you only had pin 85 wired to a ground and touched pin 86 with voltage can you hear the relay click? When the voltage is removed from this pin the relay should click as well.

Also, the alarm wire should have voltage when deactivated but a ground when activated. If this were so then the car could be feasibly started w/the alarm activated thus providing the relay coil w/a ground and then when the car is started the alarm could be deactivated causing the ground wire to have voltage which would then relax the coil and the relay contact opens up and no more battery juice for the starter.

In addition, the B/G wire going to the blower motor tells the blower when the car is being started so the blower is rendered inactive momentarily during start up to "probably" save voltage for the starter. If this is so then the blower motor can possibly be powered/wired to a fuse that is not from the IG1 bank of fuses but the IG2 bank of fuses which loses power when the key is turned to start although if the blower is backfeeding the B/G wire due to a fault in the blower than this would not be a good idea.

HAILERS2

Yeah on at least the early RX the start circuit sends power to a relay on the blower housing to turn off the blower when the key is put to Start. All power goes to the starter and none siphoned off to non essential items.

sharingan 19

iTrader: (16)

I would imagine so, will test tomorrow. Unfortunately I can't run around w/o a meter fuse...

NO!
When the key is turned from "acc" to "on" the alarm is either on or off, when the key is tuned to "start" it remains in that state and when the key returns to "on" it continues to remain in that state. It can't be used to trigger anything. Unless you are talking about hooking up some kind of override toggle switch to flip right when the key is turned to start, and then flip back off when it returns to "on".......which is just ridiculous.

Now THIS is potentially useful information. The question is, where exactly does the blower tap into the G/B wire, and how accessable is it?

Too bad it resumes siphoning power the split second it stops cranking. I have more and more respect for BMW wiring every time I work on these 2nd grade science fair projects we call electrical systems.

This is really becoming way more of a pain in the *** than an actual "fix". I'm getting close to just wiring the starter to direct battery voltage on a ******* toggle switch!

satch

iTrader: (1)

So if the car is started with the alarm activated it cannnot be turned off afterwards with the engine running? I didn't realize that.

sharingan 19

iTrader: (16)

Nope. The closest I can get is turning the key to "acc" which kills the ignition related items , but lets the car keep running. Then turn the key back to "on" which keeps it from shutting down even when the turbo timer reaches 0.

The problem is, all my electronics remain in the "key to acc" state aka useless. Which is especially bad for the heated wideband sensor.

#PieceofshitFCs

HAILERS2

************Here's the diagram & key. Note that the ignition switch wire is actually black/blue, but it's listed as black/green in the S4 FSM. This might be an '88 only thing, but I doubt it. It's probably a typo.**********************

Series five cars have the BLACK/BLUE wire at the ignition switch instead of the black/green (auto cars) or black/red (manual cars) used on series four cars.

On series five cars the power leaves the ignition sw and goes directly to the starter cut relay..............passes thru the starter cut relay and goes to the starter interlock switch........pases thru it and goes on to mate with the engine harness at a plug called X-09.

Somewhere inside the Front harness b/t the interlock switch and the X-09 is a wire splice wrapped up in the front harness. That splice has three wires. One goes to the blower motor ignition relay and another to the circuit opening relay to pull one of two coils inside that relay in to make the fuel pump work and the third wire goes on to power the starter solenoid.

You have a series five car??? manual car and never been a automatic?

HAILERS2

Series five start circuit is like the jpg attached and that jpg is for manual cars series five. It differs from the series four wiring a bit.

Looking around a bit I see I was wrong about the relay in the blowr motor housing being only on early series four. It seems to exist on all models. The start circuit just powers the coil of this relay and that takes very little power to do. Miniscule power.

sharingan 19

iTrader: (16)

I have a series 4 t2, pre 87.5 to be specific.

Edit: manual of course

satch

iTrader: (1)

If the thick B/G wire is backfeeding from the blower motor then if you're prepared to start the car w/the fan in the off position then you should be able to cut the B/G wire at the blower side of things and ground this wire. In doing so if the fan is in the on position and the car is started, the fan would continue to blow, on the otherhand, if the fan were off then it should not affect the electrical draw upon start up.

sharingan 19

iTrader: (16)

Fan is always in the off position when trying to start.

Just checked, even w/the interlock switch unplugged the G/B write still shows 5v w/ key on.

What operates on 5v? Maybe that would be the place to start? The blower motor is off. The ECU wouldn't be feeding it power. My gauges all run through the radio curcuit for power....

satch

iTrader: (1)

When you disconnected the Interlock plug and tested for voltage w/key to on did you also disconnect the B/G wire from the relay to eliminate that from possibly being a cause for the backfeeding? The B/G wire also goes to the cruise control. Cruise control runs off of the Meter fuse, and the "Vref" runs at about 5 volts.

sharingan 19

iTrader: (16)

No, I tested the B/G wire at the relay plug. It is opposite a ground wire, and the only wite w/ power going into the relay is from the battery at pin 30....i doubt the relay is backfeeding itself.

Hmmm, my car HAD cruise control. I removed the actuator, cable, and computer when I first got it, since it didn't work. Could it still be drawing current even though the computer is gone?

satch

iTrader: (1)

You could also try pulling the fuses w/the key to on while measuring for the disappearance of the 5 volts.

sharingan 19

iTrader: (16)

Done.
The only fuse that causes the phantom 5v to dissapear is the 7.5A meter fuse. Doesn't really sound like new information though... I noticed that I had previously removed the abs fuse when I removed the cpu. I replaced it , but it had no effect on the B/G wire.

satch

iTrader: (1)

Try removing the plug which has ten or so wires from the blower motor system with the Meter fuse in place and see if this makes a difference.

sharingan 19

iTrader: (16)

Done. 0v on B/G w/ blower unplugged.

satch

iTrader: (1)

Are you familiar w/why the B/G wire connects to the blower motor?

sharingan 19

iTrader: (16)

Apparently to send a signal to some relay to cut power to the blower motor on start up. Sounds go good in theory, but they failed on implementation, adding unnecessary lengths of wire and splices, ultimately contributing to the very voltage dilution they sought to avert. A wag of the finger to mazda electrical engineers.

Funny thing is, if the starter got direct battery voltage as opposed to circle jerk round the whole cabin voltage I doubt it would matter if the blower were on or not.

So to fix this it would seem I need to cut/de-pin the power wire from the blower plug and ground it somewhere. Bit if that the actual per wire, or is it just used to signal when the car is starting? Because if its just a signal wire there shouldn't be a problem, but if its the power wire....

satch

iTrader: (1)

It is to signal the fan motor that the car is starting and it does this by sending a voltage signal to the relay as the B/G wire has voltage w/key to start and this voltage goes to the coil in the relay which already receives voltage on the other side of the coil via the Meter fuse. This prevents coil excitation thus preventing the relay from closing which prevents the other coils in the other two relays from getting voltage to one side of the coil which prevents the system from turning on. When there is no voltage on the B/G wire, which should occur with the key to on or ACC, then the coil does get both a ground and voltage signal so the blower works. It would be interesting to see if you replugged the 9 wire blower plug, and w/key to on the fan shouldn't work "unless" the 5 volts going to the ign relay is seen as a ground and not as voltage. Another explanation why it would work is if the contact in this particular relay was stuck closed and the coil would therefor have no affect on the workings of the blower.