another "won't start" thread

[jburnham]

I've searched and based on what I've found, it could be several things. I'd really appreciate your suggestions on where to start.

A week ago, I drove my daughter to school and got in the drop-off line. I had the lights on and radio running - and turned the engine off. A few minutes later, when I went to restart the engine, the car went completely dead - no interior lights, no locks. I pushed the car off the road and walked her to school. When I came back, without checking anything, I was able to jump start it. When I got home, I checked the battery and it was fully charged. I couldn't reproduce the issue.

This morning, when I went to take her to school, the same issue - the interior lights were working, fan came on as I turned the key to position 2, but when I turned it to start, the entire car went dead. I disconnected the battery for a minute, but it still wouldn't start. I noticed no spark as I disconnected/reconnected the negative terminal. The battery was fully charged so I just left it disconnected and came inside to search the forums. A few minutes later, when I reconnected the battery, I got the usual small spark and the car started right up.

I have an '01 540i/6. I'm not terribly skilled and it's quite possible one of my projects has caused this issue. I've stayed on top of maintenance and the car runs very well. When I got the car two years ago, the fuel filler unlock was broken which blew the central locking fuse, so I have disconnected the actuator and replaced that fuse so the remote lock/unlock works. I also replaced a bad FSU. I have installed an aftermarket amp, DICE and speakers - I believe everything is grounded properly with no noise or issues. I have installed interior LED festoon bulbs. I broke my clutch stop autocrossing two months ago and haven't gotten around to installing the replacement. Currently, Peake reader is not showing any codes.

Based on reading, I'm guessing it is the main battery relay tripping. I suspect the clutch switch is on its way out and is flipping open closed just as I'm turning the ignition. Would that be enough to trip the main relay? Will the main relay reset itself, or is it more like a fuse that needs to be replaced? Is there another form of circuit protection which could be tripping and resetting? If the clutch switch alone isn't enough to blow the main relay, where and how should I look for another cause? Are the next places to look the ignition switch, key or EWS, starter or alternator?

[lhollis3]

Either bad battery connection or possible ignition switch going bad. You might want to check those things.

[jburnham]

I've replaced my clutch stop and adjusted it so there is just a little more pedal travel after the clutch switch is activated. I've double checked the batter connection and my amp power / ground.

Is the main relay self resetting - or is it that 200amp fuse in the box above the battery?

Ignition switch is next - since it is easy. It looks like most people still have power when the ignition switch goes bad.

[jburnham]

It happened again! I was sitting in the car with the engine off, listening to the radio for about 20 minutes. When it was time to go, I turned the key to start and everything went totally dead. This time it happened in the dark so I had to find the flashlight and go through the routine. I disconnected the ground from battery and there was no spark. I touched it to the terminal a few seconds later and still no spark. I waited about two minutes and reconnected it and everything was good.

[BimmerBreaker]

Sitting listening to your radio is not the smartest idea, cause it drains your battery. Especially if you put it in II (Acc) not I. "I" should still play radio, but II will turn on all other accesories too.

Maybe stop draining your battery?

[JetBlackE46]

Here's a clutch stop that will work with the E39 without any modification:



http://forums.bimmerforums.com/forum....php?t=1302791

[jburnham]

and it happened again....

This time, I turned everything off before turning the car off. When I came back half hour later, everthing was normal until I turned the key to start - everything went dead. I disconnected the ground for a few minutes and it started right up.

I'm going to replace the ignition switch next.

....and it happened again today. I switched to an older, known good, key to try and rule out the EWS system not liking the key I've been using. While in line to drop my daughter off for school, the car stalled for the first time that I can remember and the electrical system shutoff.

Murphy's law is alive and well and applies to my car. The absolute worst place for the car to die is in the drop off line. There really isn't any place to go and I'm stuck while waiting for everyone to finish dropping off before I have an exit. My car loves to die there.

I ordered up an ignition switch last night and it looks like I got a quick confirmation that it isn't an issue with the key. I keep trying the visor test for a bad ignition switch and everything seems normal. The battery voltage is 11.9 when the car is off and 13.8 when the car is idling and the car always starts right up on the first try when the electrical system is alive.

When I change out the ingnition switch, I'll check the loop antenna. If the problem continues, I'm really going to be unhappy.

[Taters528i]

I have a '99 528i and am having the exact same problem. It used to be pretty random but this morning it happened to me several times. When I got in my car and put the key in, the dash and radio all came on. Then when I went to start the car I heard like an electrical click and the whole electrical system went dead. When I push on the positive cable on my battery, the interior lights and electrical system come back on. It took me 6 tries this morning doing this to get my car started.

The battery connection is solid and I even took it to a shop to get it looked at. The mechanics couldnt find anything wrong with the electrical system. I had the battery replaced not too long ago also.

I had another issue this morning also. When I got into the parking garage at work, I went to turn my xenons on and my car just died. I had to hop out and reset the battery again. Its getting really annoying.

Is this just a bad ground connection somewhere or a bad ignition switch?

[jburnham]

My ignition switch arrived and I'm going to replace it this week. The last time it happened, I had disconnected both battery wires and shorted them to get it started. Last week, when I went to clean the battery terminals, the nut on the positive terminal was tight, but the wire was able to rotate on the terminal. I'm sure I had tested that at one point, but not every time I disconnected the wires. Now I've got another variable. I cleaned the posts and added a terminal spacer to make it tight.

[SCoRPioN777]

My ignition switch arrived and I'm going to replace it this week. The last time it happened, I had disconnected both battery wires and shorted them to get it started. Last week, when I went to clean the battery terminals, the nut on the positive terminal was tight, but the wire was able to rotate on the terminal. I'm sure I had tested that at one point, but not every time I disconnected the wires. Now I've got another variable. I cleaned the posts and added a terminal spacer to make it tight.

So, did replacing the Ignition Switch fixed the problem and now the car starts normally?

Please, take a look at my post, I really need some suggestions:
http://forums.bimmerforums.com/forum....php?t=1373735

Thanks!

[jburnham]

I never installed my ignition switch. When I was dealing with the broken clutch stop / switch, I kept disconnecting and reconnecting the battery cables to get get the car started. Apparently my replacement battery terminals were dirty or too small or had some issue which also interfered with starting. I replaced the clutch stop and cleaned up the switch, but continued to have issues due to the battery connection. Once I cleaned up the terminals and added a spacer to make a tight connection at the battery, everything was good. I haven't had a problem since. I can run the radio for a while with the car off, leave the lights on when turning the engine off - all of the usual stuff and have no issues.