2001 740iL starting problem

[JBrtm]

Hello all I am new here looks like a great bunch sharing information.

I have a 2001 740iL and have an intermittent problem in the starting circuit.

Symptom: Turn the key, instrument panel lights, steering moves into place, all normal. Trun the key and sometime is starts, sometimes it doesn't. By not starting I mean the starter does not pull in, just a single relay click (control relay?) the solinoid is not clicking.

When I replaced the battery the car started fine. The next day we were going to use it and it wouldn't turn over.

Then the next day it started fine, took it to the store. Came out didnt start. Then tried again and it started normally. Drove it the next three days in a row, no problems. Parked it and it has not started since. Of course it will leave me stranded one day if I continue to tempt fate.

A little more history. It is not a daily driver, 33000 miles. Usually eats a battery every 18 months to two years. I replaced the battery with a fresh one two weeks ago and have even added a battery maintainer.

There are no error messages being thrown. I am confident that there is pleny of cranking power available to the circuit.

Any ideas? Thanks in advance for any ideas on what to look at.

Best,

JB

[witeshark]

Seems like you're looking for an intermittent battery drain. A look at things like interior lighting and trunk light switches maybe. Also, I'd consider a test of all the relays.

[JBrtm]

Originally Posted by witeshark

Seems like you're looking for an intermittent battery drain. A look at things like interior lighting and trunk light switches maybe. Also, I'd consider a test of all the relays.

Thanks for your reply. I had considered battery drain initially but since replacing the battery 2 weeks ago I have not recharged it, just driven it when it does start. As I mentioned earlier sometimes it starts, sometimes it doesn't since replacing the battery. The battery is fully charged so I know there is nothing more than the normal parasitic drain of the electronics that work in the background when sitting.

The interior lighting is working fine as are all other lights. I was guessing maybe the ignition switch, the battery in the key, the starter itself or one of the control relays is the culprit. But really don't know enough to troubleshoot those things properly on my own.

Best,

JB

[witeshark]

If the battery in the key is low, is there no dash indicator of that? An inspection of all the starter components would be worth a go, I'd say.

[marti5]

Could well be the ignition switch, the E38 seems to have this problem, its not the piece you can see, its a plastc box basically, which can be found via removing the sth steering cowling.