Weird electrical gremlins
 

Sooo about a week ago I get up to go to work and turn on my e53. Normally I leave it on the Sirius setting on the radio but for some reason it switched to FM when I started the car, No biggy I thought it has done this before. I go to switch it to Sirius and it completely skips that mode, goes from FM, to CD, then straight to AUX no Sirius. Weird I thought maybe I just needed to refresh my radio or restart the car? Didnt worry too much and just drove to work listening to the AUX connection instead.

After work it gets more interesting... I get into my car turn it on and the radio/nav display does not come on at all. Along with that the turn signal indicators on the dash wouldn't come on when I flicked on the turn signal, and the seat belt warning light was on even though I was buckled in. Now this is really weird so I got the car back home and plugged it into my laptop to try and see if I can run diagnostics and clear some codes (BMW Scanner v1.4.0.9). SO I run a diagnostic and the RAD, TEL, NAV, PDC, and MFL sensors dont pull up at all/no data. Now I was really worried because my car definitely has all of those.

Did a little bit of googling and people say to disconnect the battery for a certain amount of time to reset the computers as it seems the KBus is being overloaded. So I did that tried, 10 mins, 30 mins, 1 hour, and 2 hours all did nothing. Next I read something about a iPod DICE connector on the CD changer to I pulled out my CD changer, nothing plugged into it but for craps and giggles I unplugged it completely and started the car, Voila! Everything kicks on perfectly! Turn off the car and go about my day, go back about a hour later start the car, nothing comes on again...

Back to googling and some people say a ignition switch can cause various weird electrical gremlins so I tried replacing that. Still nothing. Im completely confused on whats going on and whats causing this. Anyone have ANY ideas? :dunno:

I would start at your battery condition and charging system. Confirm those are working properly.

Is there a specific way to test this? I JUST replaced the battery about one and a half years ago and the alternator I replaced only about 5ish months ago.

:iagree: Even though you have fairly new battery and alternator. Load test the battery, most chain type auto parts stores will do it free. Charging voltage is easy to read with a multimeter at the battery connection under the hood though I think the easiest way is to unlock the cluster and go to test 9. https://www.youtube.com/watch?v=z4Kk3Q5co5c

Thank you! Okay so I did the test twice. First time I did it the battery showed 11.2V then when I switched it to accessory it went to 10.9V then starting the car took it down to 10.2V but then quickly shot up to 13.9V after the alternator kicked in. Definitely not good though so I let the car sit for a few minutes and did the test again JUST to be sure ya know? This time the voltage started at 10.4V then in accessory it dropped to 10.2V then when starting it dropped all the way to 9.1V then once again after the alternator kicked on it jumped up to 13.8-13.9V.

So I'm going to make an assumption that the problem is the battery? Thankfully mine has a 4 year warranty on it from Sams Club but here's the other thing my battery is not a AGM battery, does this matter? This is the exact battery I bought. Should I get a AGM battery instead? Does it make THAT big of a difference? Also if it matters last time I had my X5 into my personal mechanic (which was to replace the alternator and the alternator bracket) he said something about the programming of the car thinking it had a AGM battery in it so he switched it to think it has a normal battery in it.

Most newer BMW cars need programming when changing the battery but the E53 X5 is NOT one of them. If your mechanic said he re-programmed the car for the battery, I'm left wondering what it was he actually programmed - or thought he programmed. :dunno:

*edit* Unless your mechanic meant he somehow adjusted the alternator output to suit the new battery.

AGM batteries require slightly less charging voltages than flooded cell batteries and a standard charge voltage of 2.4v per cell (14.4v total) as most cars charge at will overcharge an AGM battery in the long term. AGM is better of at 13.5v -13.8v for long term charging but the vehicle normal 14.4v is ok most of the time.

Most folk seem to have no trouble when fitting an AGM battery to a car designed for flooded cell batteries (such as the E53 X5) but in a few cases where long driving is common, the life of the AGM battery may be shortened by overcharging.

That's a good question. I mean he didn't charge me for it so in the end it doesn't really matter to me if you get what I mean that way its not like he popped it on there for a additional charge.

Safe bet is the battery is bad though? Should I switch it back to whats recommended aka a AGM battery?

Get the battery load tested - then you aren't guessing but yeah, it seems like it's not holding up like it should. And an AGM is not the recommended battery for the E53 X5 but it will work ok .

I wouldn't waste time load testing that battery. Sorry to say, it's shot! If under 12 volts it is effectively dead and most likely the source of your issues. The alternator is trying to keep up but the battery isn't!

I would move back to an AGM if it were mine.

Okay so good and bad news. Good news is Sam's Club replaced the battery after testing it and it showing it was bad. Bad news is all the issues are still there, still no Nav/Radio, still no turn signal indicators or fog light indicators.

Here's the weird thing though. As I was driving I was stuck at a red light for about 2-3mins and while I was there sitting I was pressing the fog light button, radio button, turn signal stock, etc. trying to test it all out but with nothing happening. Then for a split second or two everything kicked on and on the screen on the dash something that had to of been in German popped up but I have no idea what it said besides that it started with a N and then after a second everything shut back off again.

Any ideas as to what to check next?