Roger72

14 hours ago, Greydog said:

Morning Roger

A bit confused about your checking system here

If I have read and understand it, you disconnected battery (one terminal) then placed a test lamp between the terminal and the battery. Effectively completing the circuit and reconnecting the battery?

Then began pulling fuses I guess waiting for the test lamp to go out? 

My guess is your battery is discharged not fully charged and will need recharging when recharging make sure you do it from the charge points under the bonnet to avoid damaging components or remove the battery for charging. A healthy battery should show 12.8v minimum engine off 14.2 to 14.5v engine running. Are you sure it isn't a battery fault, how old is the battery?

I may be teaching Granny here but.

To test for a drain by pulling fuses first connect an ammeter (I prefer the clamp type) open the bonnet, passenger door and boot then let the car go to sleep (takes 15 min about) check the ammeter a very small drain Milly amps is needed to maintain memory for components. If the reading is in full amps start pulling fuses and if required relays until you find the offending circuit. I have had to work through the boot fuses and relays then stop and recharge the battery. Then start the process again for the cabin fuses then repeat for the Engine bay fuses and relays. Don't forget to check the Earth Points BMW like earth triggered switching so check resistance at each point. Took me a full day on a neighbours 7 series finally traced to the FCM which needed changing.

Good Luck

Dave

 

Thanks for the reply Dave,

I was taught to take negative cable off battery. Connect test light clamp to cable then place test light to battery terminal and if bulb lights up then there is a draw or short. Radio will have a little draw but light will be very dim. My light was bright. Pulling the fuse with draw/short will cause the light to go out or dim. This was when I worked on a couple of cars in the 90s. This method is fast but maybe its not good to do on these newer cars. Dont really work on cars anymore but bought this one for my sons first car now having issues. I had the battery tested and it is good. It seems like I might of lost connection between fob and ignition. I can lock doors with fob but it does nothing when i put in the ignition. I cant even put the car in neutral to tow it to the shop

2009 328i My battery kept dying so I pulled positive terminal and put test light from terminal to positive post to see if there was a short and the light was very bright meaning a short was present. I started pulling fuses to locate the short. I was pulling fuses 1 at a time and would barely take them out. I was very careful to not put it back in the wrong spot. I ended up pulling all fuses and could not find the short. I connected the battery and the car would not start. The interior dome lights work but nothing else would power on. The fob does not click into the ignition. Battery is fully charged. I ended up checking all fuses that are marked with the key symbol and all fuses with the engine symbol and all fuses are good. Any help would be great

There are 4 wires on this relay. 1 to hot wire 1 to ground and the other 2 (red and black) lead to the main harness under the hood. When I disconnect the red and black the car wont start but when I touch them together it will start. I want to bypass this relay but dont know why its here

I have a bosch relay under my dash. Car will stall or not start if the relay is not held horizontally. I bought a new relay thinking it was bad but it’s doing the same thing. Definitely looks like an aftermarket item because of how it is jumped off wires and grounded. It goes into the main cable harness in the pic. Thought it might go to a kill switch but don’t see one. Anyone know what this is for? Tia 

I found this under my dash and wanted to know how it works and what it does.