dave007

iTrader: (1)

I've fought this problem for the past 7 years on my s4, occasional clicking at first, but became regular. Replaced the ignition switch, circuit opening relay, Installed a jumper in place of my starter cut relay, installed new battery cables, cleaned all contacts, and rebuilt my clutch switch. None of these items visibly looked bad, but I was trying to find the problem. After replacing each item the car would perform better for a few days, but inevitably the starter issue would resurface.

Several months ago I cut the b/w wire at the starter solenoid a few inches up the cable. I found the copper wire black with corrosion. We all know corrosion will ruin a cable. Just for kicks I removed the starter cut relay, crimped a single male connector on a piece of 12 ga. wire plugged that into the relay socket at the Black/Green wire, and ran the other end to my starter solenoid. Car started every time! I had cold start issues (starter engaging fine, but engine not starting), and later realized that the Black/white wire to the solenoid also sends a 12v signal to the ECU so that it knows the car is starting. I went back and spliced the Black/white and my new wire together below the relay. Reinstalled the original relay (which is normally closed, by the way, only cuts when the alarm system opens it, so contacts shouldn't be bad). Now there's a new corrosion free wire going to my starter and the old b/w provides power to the ECU and other places during starting. All this to say, the wire to the starter itself had more corrosion in it than any other item in the start circuit. I have tested, replaced, or rebuilt each item individually over the past few years. One wire fixed my problem. Anybody up for cutting the black/white wire at the starter and telling me what you find?

dave007

iTrader: (1)

Also, if you want to do the relay mod., the solenoid does not require 30 amps to operate, but that old wire to the solenoid might pull twice the amperage required. Here's a nice relay and socket to use:
http://www.bgmicro.com/REL1068.aspx

http://www.bgmicro.com/REL1060.aspx

Can't beat that! $1.39 for the socket with lead wires, and $1.99 for the relay! Shipping should be around $2.

mattfromthepier

I did this mod and it worked great! My car starts every try now, but I made a mistake and used a cheap crap relay that stuck after 20 or so starts and then like some crazy car voodoo the starter kept cranking! It was a terrifying experience, I would recommend doing this mod and 1. using a good relay(DUH!) and/or 2. wiring in a cutoff switch incase your relay sticks

sharingan 19

iTrader: (16)

I have the stock security system (actually I think my car had every stock option...) However I do not have the starter cut relay, instead I have the blue jumper connector. Is the starter kill a function if the alarm cpu? Was it an option?

I ask because I tried to follow this diagram, but it wouldn't work. It makes it seem as if one could replace the starter cut relay w/a normal automotive relay and retain the feature which is what I attempted to do thinking someone swapped must have swapped out the relay at some point. I checked the voltage and the "alarm" wire was showing 12v w/ key on. Eventually I just pulled the second relay and wired it up as Hozzman indicated.

It now cranks every time!
Unfortunately it also revs up to 2,000 rpm every startup even when already warm. I suspect it has something to do w/the ignition because if I turn the ignition off and let it run (turbo timer) it idles/runs perfectly fine.

satch

iTrader: (1)

If you wanted to place a relay in place of the missing relay you would wire the relay such that the "coil" received voltage w/key to on (not start) and the Lightgreen/Yellow wire from the alarm would supply the ground signal for the coil to complete the circuit. The wire from the alarm is supposed to supply a ground signal when disengaged, and when it is armed to prevent the car from being started, the LG/Y wire would have voltage on it thus preventing the coil in the relay from being excited which would prevent the relay from closing and allowing voltage to pass on to the starter solenoid.

sharingan 19

iTrader: (16)

Thanks for clearing that up. So the problem was that the alarm wire seems to be armed for some reason or another. Guess it could be a problem w/the cpu? Odd; my security light doesn't seem to work anymore either, but the alarm works, so it could just be the bulb.

Oh well, it cranks like a real car now. I'm not so worried about the alarm. What is pissing me off is this 2,000rpm start up bullshit. Before the starter mod the most it would ever rev to on startup was 1500 and it would come down as it got warm. Now it stays @ 2k until I turn it off

satch

iTrader: (1)

An S5 has the alarm system incorporated into the CPU but this is not the case on an S4 as it has its own control unit which is separate and distinct from the CPU. Also, the starting circuit is unrelated to the operation of the engine so there must be other intervening variables at play here to cause your symptoms. I would focus on the Air Bypass and BAC.

EDIT: Another thing regarding the starting circuit is there are two B/G wires but they differ in that one supplies voltage w/key to on while the other supplies voltage w/key to start. The one that supplies the voltage w/key to on goes to the coil and the "start" supplied voltage goes to the relay which supplies voltage to the B/W wire that leads to the starter. If these two wires were perhaps crossed it would cause the starter to engage constantly if the coil in the relay was not behaving properly (in other words allowing voltage to constantly be supplied to the starter w/key to on instead of just when starting the car).

RotaryEvolution

iTrader: (30)

there is about 5 different issues that can pop up with the starter circuit and all have very similar symptoms.

satch

iTrader: (1)

In looking over the wiring diagram for the starting circuit which includes the starter cut relay indicates the relay contact to "already be in the closed position," which is different from most of the relays in the car which are usually open and requires the excitation of the coil to pull the contact closed so the current could properly pass through the relay. So, if the diagram is accurate, then my explanation is wrong as the LG/Y wire coming from the alarm control unit would have voltage on it when the alarm is in the deactivated mode and when activated it would supply a ground signal to the relay to create an open circuit in the relay which would prevent the current from passing through. Sorry for the misinformation, and I apologize.

sharingan 19

iTrader: (16)

When I first wired it up (w/ 2 relays) I wasn't sure which B/G wire went where, I switched them but it did nothing because the security wire had a constant 12v. On that note, when I said "cpu" I was talking about the security cpu, I was unaware it is different for the s5.

When I pulled the second relay I reviewed Hozzman's post(s) and found that the thicker B/G wire is for the ignition switch/interlock so that is the wire I used. It started right up, but it immediately rose to 2k and stayed there. In fact something started smoking, but it was not electrical (prolly oil from repeated starter removals/installs). I thought my grounding location for the relay might have been the issue (ground plug on the back side of the shock tower under the trailing coil ) so I moved it to the bolt on the coil mount, but that had no effect on the 2k situation.

As soon as I turn the key from the "on" position the rpm drops to normal. This is not a vac leak or bac issue (bac is almost closed as I was previously trying to get the n390 afm to idle). Nor is it related to the intake at all, it will go to 2k w/ the n318 afm or the n390 afm. (it will not idle w/the n390, so afm input is ignored when this problem occurs.)

No problem. That makes prefect sense, seeing as how I tried to duplicate that setup w/a standard automotive relay and it did not work. Perhaps the diagram should be amended to reflect the "backwards" operation of the stock relay and prevent such misunderstandings in the future. Also, I guess my security cpu is working fine, would just need to find a stock starter cut relay to follow Rocket's diagram.


...

RotaryEvolution

iTrader: (30)

wiring in a relay at the starter itself using the high amp start signal wire to convert it to a low amp trigger circuit for a relay, powered by the battery wire off the starter itself is the easiest fix. this takes all the load off the ignition switch and relays in between. so even though the high resistance in the start circuit may not get the solenoid fully kicked over it can get a relay to jump full juice to the starter via direct battery voltage.

sharingan 19

iTrader: (16)

Not quite seeing how that solves the 2k rpm startup or explains why it happens. But thanks for taking the time to reply.

HOZZMANRX7

iTrader: (43)

To be honest, I just don't see how a wiring fix to the starter would have any effect on the idle. Two entirely different circuits, so I have to believe he disturbed something else while in the process of doing the sticky starter fix that is causing the idle issue.

The starter cut relay itself only relates to the factory alarm system.

sharingan 19

iTrader: (16)

To be accurate, its not "idle" its something related to startup or the ignition switch as it only happens after the key is in the start position and continues as long as it remains in the "on" position. I don't understand how it could happen either, but it did. I don't even have the starter cut relay, hence why I had to follow your original instructions as opposed to Rocket's diagram.

If the engine is cold it will jump to 2k and stay there until the key is turned to acc, then it will drop to 1400-1500 (where it normally sits during warmup)

If the engine is warm then it will jump to 2k and stay there until the key is turned to acc, them it will drop to 750-850 (THAT is idle). Furthermore when the engine is stuck @ 2000rpm its not reading from the afm, almost as if its some kind of closed loop operation.

satch

iTrader: (1)

From your explanation are you suggesting that with the car idling higher than normal you can turn the key to ACC and the engine still runs, but albeit at a lower RPM?

sharingan 19

iTrader: (16)

More like reving than idling really.
As mentioned earlier, I have a turbo timer, so yes, the car will run when the key is tuned to acc. In fact it runs normal when the key is turned to acc. The problem is related to the key being in either the "start" or "on" position, because as soon as that is no longer the case, the problem goes away....as in its revving at 2,000 rpm w/ the key to "on" turn the key to "acc" and it instantly drops to 750-850 (until it shuts off).

sharingan 19

iTrader: (16)

Checked the voltage at the relay while the engine wa revving to 2,000. Apparently the starter is not disengaging....

Ground: 0v
Batt: 12v
Starter solenoid: 12v
Interlock/ignition: 5v

With the key to "on", the interlock/ignition wire shows 5v....should it? I assume When the key is turned to "start" it sees 12v. This closes the relay and connects the batt write to the starter solenoid wire. The problem seems to be that after the key is returned to the "on" position the starter solenoid wire still gets 12v. Suggesting that the relay is not reopening as it should. The 5v reading on the interlock/ignition write isn't enough to activate the relay (otherwise the starter would run before moving the key to "start") However, might the 5v reading be enough to keep the relay from reopening, and thus not allowing the starter to disengage?

I thought it might be the relay, but swapping it out made no difference. Does the relay need to see 0v to re-open? Should the ignition/interlock switch have 5v w/ key on?

satch

iTrader: (1)

I think I hit the nail on the head earlier and then maybe I didn't but if you crossed the B/G wires at the relay it would cause the starter to receive continous voltage w/key to on and the relay coil used by the alarm system would receive voltage w/key to start. If the B/G wire at the Interlock switch has 5 volts then its likely because the LG/Y alarm wire is carrying 12 volts and it would bleed through the relay coil and cause the wire connected to it on the other side of the coil to have minimal voltage perhaps. In closing, if the wires were switched (B/G's) then the car should start w/o the clutch being depressed. Try it!

sharingan 19

iTrader: (16)

Tried it, it doesn't work....or more accurately, it works too well. The starter engages as soon as the key is turned to on! The small G/B write is constant 12v, thus closing the relay.

I do not have the stock starter cut relay. I only had the blue jumper plug which connects the large G/B wire to the B/W wire. The relay connects the batt wire w/ the B/W wire, using the G/B wire as a trigger.

The problem is that the B/W still gets 12 after the key returns to on, keeping the starter on.

satch

iTrader: (1)

If the only wire you have jumpered to the B/W wire is the large B/G, which is supposed to have voltage w/interlock switch depressed and the key to start, then unjumper the wire and see if the B/W wire still has voltage on it w/key to on. If it does then the source of the voltage on the B/W wire could then be narrowed down and determined.

satch

iTrader: (1)

Also, the B/W wire connects to pin 3B of the ECU and also to the blower motor for the fan. If the B/W wire has voltage w/key to on but not jumpered to the B/G wire then it is likely being backfed by one of these two wires. The blower motor is powered by the Meter fuse and one of the 30 amp circuit breaker fuses. If removed and the B/W wire has no more voltage w/key to on and not jumpered then that was the source of the backfeed. If it still backfeeds then pin 3B of the ECU should have less than 1.5 volts when idling. If the pin were perhaps depinned and the voltage on the B/W wire changed then that was the problem.

sharingan 19

iTrader: (16)

Nothing is "jumpered".
I HAD a blue jumper plug instead of the starter kill relay.
I removed the plug and wired up a standard automotive relay to supply battery voltage to the starter solenoid wire.

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)

The b/w wire FEEDS the starter solenoid, if it had power, the starter would turn.

The thick B/G wire shows 5v w/key to on and i assume it shows 12v when the key is turned to start (i "assume" because I can't stay the car and hold the relay and check it at thee same time). I'm guessing it SHOULD show 0v unless the key is turned to "start" and the clutch is depressed....but I don't know for sure.

What I do know is that the RELAY DOES NOT REOPEN AFTER STARTUP!!! For whatever reason it remains closed, thus connecting the battery wire w/the starter wire and causing the starter to continue running.

I suspect this is because the trigger wire (thick B/G) maintains a voltage of 5v anytime the key is "on" . When the key is turned to "acc" the trigger wire gets no voltage and the relay opens, allowing the starter to disengage. SHOULD THE INTERLOCK/IGNITION WIRE (the thicker green and black wire) SHOW 5V WITH THE KEY IN THE "ON"POSITION? If not, then this is probably the problem, why would this wire have 5v?

satch

iTrader: (1)

If the bolded info is correct then the problem is the coil is constantly receiving a ground on one side and a voltage source on the other so the relay will stay closed on a constant basis. The role of the coil should be that it closes only temporarily and the only way for this to occur is either the voltage source needs to be interrupted or the ground source needs to be interrupted and with the way you currently have it wired it would be a pain in the ***. The use of the battery as constant voltage for the coil is not going to work at all.

MAJOR EDIT:The thicker gauge B/G wire should go to the coil (positive side) and the thinner B/G wire to the relay that would supply the B/W wire w/voltage. Key to start/clutch depressed and the thick B/G wire feeds the coil which already has a ground on the negative side. When this happens the relay closes and the voltage on the thin B/G wire passes onto the B/W wire. When the clutch is released the voltage to the coil is cut off and the relay relaxes and opens and no more voltage for Mr. Starter.

sharingan 19

iTrader: (16)

I know how a relay works, its the shitty mazda wiring that's confusing.

Would someone please just tell me if the thick G/B wire (interlock/ignition) is supposed to have 5v w/key on?!?!

It would make sense that it should be 0v at all times other than startup. (But if it did my current setup would work...).

So are you are saying there is no wire that is only active when the key is in "start" position? The thick G/B (ignition/interlock) still has 5v when the key is @ "on".

The thin G/B wire is constant 12v so that would be useless as there is no switched ground wire in the ignition curcuit.

Feeding the B/W wire w/ the thin G/B wire defeats the entire purpose of this thread it passes through just as much crap as the G/B wire. Plus it is constant 12v just like the battery so it would do nothing to change operation of the relay either.

satch

iTrader: (1)

How could the thin B/G wire, which has voltage w/key to on, pass voltage to the B/W wire if the contact is open? Not possible. First off, it is not constant power and even if it were it would not be able to pass the voltage if the contact were open. If you knew how the relay works then why do you have the coil wired with both a constant ground and constant voltage source. This means as long as the battery has voltage it causes the coil to excite 24 hours a day, seven days a week. "If" the relay you are using is like the Main Relay, which normally has an open contact until the coil is excited, then the way I describe will work. Lastly, the thick wire having any voltage is immaterial if the coil side of the relay is wired correctly.

EDIT: The thick B/G that is wired to those who have a Starter Cut Relay is wired to the side of the relay which passes voltage onto the B/W wire. Now the contact in this relay is normally closed so if there was any voltage on this B/G wire then it would pass onto the B/W wire, no problem.

Also, the thick B/G wire is tapped into by the blower motor on turbos w/ABS. If your car has ABS then disconnect the plug to the Interlock switch and check the thicker B/G wire for voltage w/key to on. If you have the same 5 volt reading then the blower is backfeeding this wire.