Car will not start

Rudy3.0CS

Rudy3.0CS

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Perhaps a silly question, but it wouldn't be my first. I am in the early stages of restoring my 1973 CSA. The car was running fine before I started to disassemble trim, lights, windows etc. The goal was to keep it driveable until it goes to VSR in 2 months for a new engine, coilovers and more modern 4hp22 with standalone transmission ECU. Mario and Chris prefer to get a baseline on what we are dealing with. My problem is that I can no longer start the car. The grounds for the head and taillights are disconnected. The windows front and rear are out of the car. Dash is intact, as is the console. Could I have done something obvious and that's the issue?
Thanks in advance.
 
The best way to find the problem is to make a complete list everything you have done since the car last ran.
 
Car is in park. The P light is on. Power to blower. Gauges. I removed everything in the trunk light wise, labeled the wire ends. Tank in place with sender. Removed the headlight buckets and side markers. Front fan and condenser. All the ancient AC hoses. Removed the dash pots and vacuum lines. Plugged the ends. No crank. No solenoid click. Windows front and rear completely out. So while it doesn't start today, it is the most rust free E9 I have ever seen. The inside of the rockers and bottom of fenders are as new. Not even dirty. Only corrosion is a minimal amount of surface rust at the back of the fuel tank. So while that is an aside I am super pleased with my BAT purchase from last year.
 
I'm in a somewhat similar situation, car won't crank, and the alternator light on the dash doesn't come on when I turn the switch.

When you turn the key, does the alternator light come on and the oil pressure indicator light up? If you get the dash lights working so can then assume the ignition is powered. Verify the ignition is powered by checking for voltage at the coil.

Then see if the ignition switch activate (ground, IIRC) the starter solenoid?

Also, the original BMW diagnostic plug under the hood must be unmolested. One pair of the wires coming into it have to be connected, you can't simply remove the diagnostic plug (DAMHIK).
 
Pull the bottom wire at the starter off. It's the big black wire at 6:00

connect your voltmeter to it-red lead and black lead to ground at battery

turn the key all the way and note whether you have close to 12 volts.

if you do- it's in the engine bay.
if you don't its under the dash.

Your answer?
 
Will do that first thing in the morning. Battery is on the charger. My voltmeter was at my house and the car at my shop. The lights on the dash light up. I haven't been under the dash at all which makes this all curious. BTW the diagnostic plug is intact. I was looking at it and thinking I would loan it to my 2002 which is basically done. The E9 won't miss it for quite some time.
 
More info:
Battery voltage 13.65v
I removed the heavy cable Don asked about. O volts with the key turned. Interestingly, that wire sparked like hell when it hit the base of the carb above it.
I also checked the voltage in the skinny wire the plugs into the top position of the solenoid. That had 7.65v with the key turned.
When the key is turned, the relay on top of the steering column clicks.
That's all I have!
Thanks again.
 
More info. I looked again and realize that I removed the black power cable to the starter. That's what sparked. I checked the power of the wire at the one oclock position and that was 7.65v. I hadn't even seen the smaller black one. Tested that and nothing at all. I used a remote starter switch and the car turned over immediately. The car is an automatic with the relay mounted on the booster mount. That clicks when I turn the key.
 
Problem solved. I wasn't getting any power to the red wire on the automatic starter relay. I traced that back to pin 4 on the fuse block. While the fuse looked intact, there was a faint black mark behind the center of the fuse wire. I removed it and the wire fell apart. Swapped in another white fuse and perfect. How and why that fuse blew will likely remain a mystery.
 
Not trying to add any complexity, but this is one nice thing about the newer fuse boxes which have a green/red LED to show when they are correct. That immediate indicator has made troubleshooting a lot easier
 
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It's already on my parts shelf. I bought one for 2002 and thought it was a very worthwhile upgrade. Would have saved me half a day of messing around. And the first thing I checked was the fuse block.
 
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