M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => General Topics => Topic started by: shayne_bermudez on March 04, 2014, 04:10:24 PM
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Please help ! 91 318i .......if i pull the key from the ignition it stays running...i pulled the #10 fuse and it shuts off how it should when i remove the key.....also the little wire on my starter sparks and heats up. Theres one yellow and one red light lit up on my cluster if that helps. I can do almost anything but when it comes to eletrical im stuck !! Any comments and help will be appreciated emensly!!! Feel free to text 8607970887
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check wiring on starter, they might be shorting and keep the car on.
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You might also have a broken ignition switch. Pull the steering column apart and check the bottom part of the ignition switch. It's a red plastic circular plug on the left side, opposite the key switch.
The black/yellow wire that goes to the starter is the signal wire off the ignition switch - should only carry voltage when the key is in the start position. Find out if the starter is stuck and somehow shorting that signal wire.
You usually don't see E30s with ignition switch troubles - the E36s had some problems with them.
Don't be afraid of the electrical systems. They're usually the cheapest problems to fix. Do you have the electrical troubleshooting manual? I like to use this one, the E30 'vert ETM. (http://wedophones.com/Manuals/BMW/1992%20BMW%20318ic%20Electrical%20Troubleshooting%20Manual.pdf)
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No i dont have a manual of any sort. Would the ignition switch be the reason for it to heat up? That wire got really hot almost like something was getting back fed through the wire
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check wiring on starter, they might be shorting and keep the car on.
Grounding on eachother?
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Its the green and black wire getting really hot on my starter
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Does the wire on the starter heat up/spark once the motor is running or just on start?
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Sounds like a worn out ignition switch to me ... I would invest in a shop manual ... Should find a good copy on Craigs, or Ebay ...
http://www.bentleypublishers.com/bmw/repair-information/bmw-3-series-e36-1992-1998-repair-manual.html
http://www.bentleypublishers.com/bmw/repair-information/bmw-z3-1996-2002-repair-manual.html
http://www.bentleypublishers.com/bmw/repair-information/bmw-3-series-e30-1984-1990-repair-manual.html
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Here is the starter wiring, hopefully it helps.
(http://www.m42club.com/forum/index.php?action=dlattach;topic=18195.0;attach=3710)
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Its the green and black wire getting really hot on my starter
Nice post, Slowered! Shayne, that's a page from the ETM - like a flow chart for the starter wiring & circuits. Does it make a little more sense now, or is it even more confusing?
Here's my take on the wiring diagram. The black/green wire looks like it should only carry power at two times.
1. When the ignition switch is in Run position that black/green wire is grounded through the starter.
2. When the key is turned into the 'Start' position, BMW does a little electrical trickery. The unloader relays get +12volts on both control terminals. That cancels out, so the relays shut off. Those two relays are called 'unloaders' because they disconnect non-essential electrical systems when the car is cranking. That gives the starter more amps.
Those "unloader" relays are the normal Bosch 4-pin 30amp units that almost every car on earth uses. The BMW relays look a bit different, but they work the same way. They basically just have a prettier case and an inline resistor to cut down on arcing in the ignition switch. I'd also suspect they also have a diode internally to prevent current flowing the wrong way. If that's true, and the diode is burned out, that black/green wire would short back to main power, and definitely get warm!
I can check my relays tomorrow to verify my little theory. I'd start checking the unloader relays K5 & K7, and the ignition switch. Do you have a multimeter?
Does the battery ever need to be recharged, or does it hold a charge between starts?
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Thanks for deciphering my post haha.
Unfortunately I don't have much input on the starter problem aside from the schematic. I recently found it when cleaned up the battery junction block, something I would recommend as you can lose voltage if the contacts are corroded.
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Hey guys the smallest wire (green and black )which i think is the ignition switch that runs to my starter began to melt. Why?? Do you guys have pictures of the wireing on ur starter? How do i fix this i have 3 wires thanksss
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I merged these two topics. I'd suspect you have a bad starter, engine grounding strap, or possibly a bad ignition switch. Here's a link that might be helpful:
http://www.e30tech.com/forum/showthread.php?t=37728
Did you change out the starter with a rebuilt unit? Here's a thread (http://www.r3vlimited.com/board/showthread.php?t=140181&page=2) about AutoZone rebuilt starters that are advertised as fitting our cars, but need a bit of rewiring to fit in our cars.
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Thanks for deciphering my post haha.
Unfortunately I don't have much input on the starter problem aside from the schematic. I recently found it when cleaned up the battery junction block, something I would recommend as you can lose voltage if the contacts are corroded.
yes i have a multi meter nad no my batter wont hold a charge.
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Sounds like a worn out ignition switch to me ... I would invest in a shop manual ... Should find a good copy on Craigs, or Ebay ...
http://www.bentleypublishers.com/bmw/repair-information/bmw-3-series-e36-1992-1998-repair-manual.html
http://www.bentleypublishers.com/bmw/repair-information/bmw-z3-1996-2002-repair-manual.html
http://www.bentleypublishers.com/bmw/repair-information/bmw-3-series-e30-1984-1990-repair-manual.html
it does it while the motor is running
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So heres what i did:
I had an extra starter so i build one good starter from the two.
Installed it and the car runs fine. When i hook up the green and black wire to the terminal it shorts and pops my #10 fuse. ....im thinking that wire needs to be replaced completly because its groumded somewhere
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Are you sure you didn't pinch a wire inside the starter?
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Are you sure the starters are compatible? There was a change between the early and late model E30s. Check out this post:
http://www.r3vlimited.com/board/showpost.php?p=1541256&postcount=8
Here's the explanation:
I wouldnt replace the starter, I'd move the wire to the other terminal.
Relay terminals 30 and 87 are switch terminals, and 85 and 86 are coil terminals. The locations of the terminals themselves on the relay is non-standard. (thank you BMW...)
Switch terminal 30 is connected to battery positive via (IIRC) C100 which is a lug inside the fusebox. Always hot.
Switch terminal 87 goes to all of your stuff that doesn't work, namely windows, aux fan, blower motor, seat heater, etc.
Coil terminal 86 is connected to the ignition switch, and receives positive voltage any time the key is on run/start.
Coil terminal 85 runs to the starter through C101.
Ok, 86, 87, and 30 are straightforward enough I believe, let me explain what is supposed to happen with 85.
The two relays terminal 85 are wired in parallel, run through the engine harness, then through the starter solenoid windings to ground. With the key in the run position, terminal 86 supplies power to one side of the coil, and the starter solenoid windings provide the ground through terminal 85, engaging both relays. This works because the resistance of the relays is high enough that they do not flow enough current to come close to engaging the starter solenoid.
When starting, the connection to the windings supplies positive voltage to terminal 85, resulting in a voltage difference of 0v across the relay due to terminal 86 still being connected to power via the ignition switch. This causes both relays to disengage, removing power from the various high current draw accessories in the car.
Your issue is essentially an open connection at the starter solenoid. You are measuring the positive voltage through the relays. If you were to ground that wire, you would lose the unloader function, but the accessories would still be ignition controlled via terminal 86.
What happened is, back in the days of carburetors and distributors and other scary things like that, some cars used either a ballast resistor, or resistor wire to drop battery voltage going to the coil so you didn't cook your points and/or fry your transistorized ignition amplifier (cutting edge!)
Voltage drop during cranking became an issue however, so starter solenoids began incorporating another terminal which was just another contact that the starter solenoid disk connected during cranking, connecting both large terminals and the new small terminal on the solenoid together. This small lug was run to the coil in parallel with the resistor wire which was run through the ignition switch like usual, to provide full battery voltage during cranking only. Any other time that terminal was an open circuit so the ignition circuit could do its thing.
OK, fair enough. The point? BMW's fourth terminal doesn't work that way. As it is from the factory in the cars with 4 terminal starters, the fourth terminal connects to the motor terminal, the big one opposite the battery cable connection. This provides the ground/positive signal used to drive the unloader relays like I mentioned before, just using the motor windings as a ground path versus the solenoid windings. Small taillight E30s used three terminal starters, and there was a factory splice to the starter solenoid wire from the unloader wire somewhere in the vicinity of the fusebox. You would essentally be converting your car to the early style unloader circuit by running your unloader wire to the starter solenoid lug.
All that said, many people just ground the damn thing and resist the urge to crank the car while rolling down the windows with a low battery. Either scenario works. Or you could change starters to one with the fourth lug labeled "30h".
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I'm still suspecting the ignition switch. It's just a plastic rotary switch, it could be worn out.
Next time you pop fuse #10, see if that green wire off ign switch term #15 has +12v even if the car is switched off. I'd think that if that part of the ign switch was melted and it kept the circuit closed, it'd keep the car running even if you turned the key off.
I'd also think that if one of the unloader relays is shorted/damaged (or maybe an incorrect part), it would flow enough current to overload the #10 fuse. I'm told that the relays are always grounded through the starter in 'Run', but the resistance is high enough that the starter won't run. Those relays have built-in resistors that (might) prevent too much current from flowing through the black/green wire.
Could also be the starter. You're sure the terminals on the starter are wired up correctly both internally and externally?
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Yea im about 95percent the starter is ok. I wonder what would happen if i just taped up that wire and just ran without it....id just have to be careful not to use my windws or anything
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I'd be inclined to check the relays and ignition switch to fix the problem. I try to avoid jury-rigs.
At least try to see if that wire is shorted to ground. Pull it off the starter, pull fuse #10, then test both ends of the wire for continuity to chassis ground. It's an easy test and will start eliminating possible problems.
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So i took advantage of the nice day and did some work. I fixed my sunroof and i fixed my power windows. I pulled off my valence to find that my fog light on the driver side stays on no matter what and my passenger side fog doesent work at all and i know the bulbs are good because there brand new
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Sometimes a few weeks break helps.