'97 E420 Died on Highway
 

I bought this car apx 3 weeks ago and have had no problems what so ever. Last night all of the sudden as I'm driving down the highway my car just cuts out completely. No sputtering or noises, no idications what so ever. The engine just stopped running and I coasted to a stop. No matter how much I tried it would not restart, no matter how long I waited. It would crank like a champ just never actually start. After reading other posts and trying to diagnose myself I was leaning towards thinking it was the fuel pump. I can hear the cranking start to slow from the battery loosing power because I have tried cranking it so much while doing tests. I went to the store and got Carb cleaner and the diagnostic tool from Auto Zone to pull codes. I ran the scan and it came up with NO codes at all. Then I decide to try the Carb cleaner. I was going to spray it in the air intake while cranking it to see if it would start to come to life. Well, now when I try to start it there is just a very fast clicking and it doesn't crank. I thought the battery might just not have the power to crank it now and so I hooked up my backup battery pack to it to let it charge. Please someone help me I am pulling my hair out.

RE: '97 E420 Died on Highway
 

It could be a crank angle sensor. These do not come up on the fault codes, unless you have tried to start the car and then check for fault codes before switching the ignition off.

The crank angle sensor is on top of the flywheel housing, and if you remove it and measure it with a multimeter, It should have 600 to 1200 ohms resitstance.

If you don't have fuel pressure, It could be the fuel pump, or the fuel pump relay, which, on your car should be under the back seat, attached to the side of a fuse module.

RE: '97 E420 Died on Highway
 

NEW INFO
After doing a bunch of tests, I started checking all the fuses. I found a blown fuse that is labeled ignition coil. I thought sweet, I just have to replace the fuse and I hopefully it will start. Well, it fired up and then quit a second later. Checked the fuse and it was blown again. So, question is, what causes an ignition coil fuse to blow any time the engine is running?

RE: '97 E420 Died on Highway
 

Have a good look at your wiring harness for points where it is shorting to earth.

SUCCESS!
 

Well, I tracked the wires that the alarm installer had coming through the firewall. One went to the siren and one went under the cover of where the coils are. The idiot just ran the wire under the side of the cover, so when it was bolted down it was putting considerable pressure on the wire. I guess the heat and pressure only took a few days before cutting through the shielding and contacting the metal below the cover with bare wire. I repaired the wire and then ran it through where the other wires enter under the cover. No more short, everything runs like a champ, and my alarm works like it should. Thanks for all the help guys. I appreciate it. One more reason to do everything myself.