03 540i odd issues

[Rkeondre]

So I have had a 93 740il for a couple of years now and I ha a friend leaving to be deployed and he offered me his 03 540i M Sport (it's a real one) for $1500 so I got it he aid he thought it needed a alternator and a break line was broken. The car hadn't been moved in 8 months so I charged the battery went to jump it all the lights were on and then nothing so I did the touch the wires together thing and when I reconnected the battery the nav screen pops up a code and a 10 minute count down I didn't know the code so I let it count down. It finished and the car started and drove fine. But then a few days later I noticed the turn signals worked on the outside of the car but didn't indicate on the dash when the headlights and fog lights are on the indicator in the instrument panel didn't show a light anymore but after sitting overnight it started working again. The windshield wiper switch does nothing at all noticed that in a downpour and barley made it home... also the nav screen goes on and off while driving constantly resetting itself none of the functions work on it but the right knob it let's you go through the car data and stuff the but the code one is greyed out. Also sometimes all are greyed out. Also the interior dome lights don't work I've checked all the fuses and they all seem to be there. Also it does the shutdown thing asking for the code probable once every other day. I now have the code so when it does it again I'm going to put it in and see what happens but does anyone know what could be the problem with this I've looked through forums that said they useing the visor it doesn't do anything to the radio or steering wheel when I try them. Anyone I'm confused AF and not starting to think the deal I got wasn't that good.... any help would be lovely please!

[DustenA]

I would start with ensuring the charging system is working. Charge the battery fully. Let the car sit a few hours and check the voltage. IT should be 12.4-12.5
IF its up to snuff then check the voltage while driving. you can access the high obc and monitor it while driving(do a search on obc hidden function).
A lot of funky electrical issues can be caused by a lack of power.

[Rkeondre]

I did a check it pushing about 13.4 volts sitting with the air on haven't tried it driving yet

[DustenA]

That's a bit low, but not the worst.

[JimLev]

13.4 is fine.

[Uturn540]

Have you checked the infamous E39 water reservoir, the one under the passenger seat. It is known to cause all kinds of issues.

[jclausen]

Ignition switch

[geargrinder]

Have you checked the infamous E39 water reservoir, the one under the passenger seat. It is known to cause all kinds of issues.

Ignition switch

I like both of these suggestions, although the first the most.

OP - read up on water getting into the floor of the car and causing all kinds of problems.

Also minor thing but... friendly suggestion: try using the 'enter' key sometimes and making paragraphs in your posts. Lotta guys won't even read your stuff when you type BLAHBLAHBHABLAHBLAHNOPARAGRAPHS100SENTENCES.

[BimmrMeUpSnotty]

Maybe that's just how he speaks...

[s12512]

Sounds like the ignition switch. Might wana start there

[pleiades]

Rkeondre, if the car sat that long without the battery being kept charged (trickle charger, battery tender), the battery might have sulfated enough to have dead cells. Find out how healthy that battery is. If it's in poor shape with any bad cells, it won't have enough amps to power everything even if it shows a good reading on a multimeter.

Not only that, but if the alternator is constantly trying to keep that battery charged, you'll see a low voltage reading with the car running. This can eventually kill the alternator because it's not designed to be charging a low battery. 540i alternators are not cheap.

[Rkeondre]

What do you mean by the water reservoir I've searched for it and can't find anything???

Also I put a brand new battery in it the battery is fine and I know I already bought another alternator I just haven't put it in because it doesn't seem to be the problem. I'm going to buy a ignition switch Monday and see what happens.

Another thing what are your guys thoughts on keeping the stock widescreen gps or getting a aftermarket one?

[geargrinder]

Water reservoir is Uturn's joke. It means there are 2-3 ways water can fill the floors under the carpet and cause all kinds of really weird and effed up hassles.

[Uturn540]

What geargrinder said, There is a fuse panel buss under the carpet under the front passenger seat. It is recessed below floor level and any water seeping in will end up submerging the area. Check out this thread, especially post #16
https://www.bimmerforums.com/forum/s...ght=fuse+water

[NordmanMg]

On enter-code thingy, you need new GPS unit

[ViolinARC]

My vote is for a ground block short (time to start checking the wire looms). From what I've read, sometimes the solder points will get loose over time and cause these kinds of odd, intermittent electrical gremlin issues...

EDIT: As for the wiper issue, treat your windshield with Rain-X or my preferred treatment, Rain Clear by Glass Science. The awesome thing about this stuff is that it can also be used to refresh the non-glossy trim on the door pillars/windows and around the sideview mirrors...