When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
In short, had engine misfires and stalling on start - checked high pressure fuel pump (replaced last year) electrical connector - unplugged it a couple of times and reset, All good - fixed. However, in the middle of the operation somewhere I noticed that the door chime was no longer working. Thought that was odd, but paid no attention because of the engine thing. Drove it today and noticed that the radio is inoperable and the display is out. I guess that the door chime must go through the radio to the speakers, so that's explained, but I don't know what happened to the radio. The fuse for the radio and display is good and I checked the fuse for the amp and that's good. I don't know what the heck I did, but I'd like to fix it.
Which specific fuse did you check and how did you test it?
I looked at two:
F23 - 10A, radio and display
F5 - 15A, amplifier (sticker lists it as 20A)
I just looked at them - the filament was unbroken, so I figured that was it. I don't have a powered multimeter - guess I should get one.
10A fuse 23 is your main focus, but you can do the following voltage tests using a digital multimeter on both fuses.
You can buy an adequate digital multimeter for under $10 at Harbor Freight Tools.
Each fuse has two metal test tabs at the top. Set the multimeter to read DC voltage. Touch the red multimeter probe to one test tab and the black multimeter probe to body ground (e.g., one of the fuse box bolts). With key turned ON, your multimeter should read battery voltage (~12.6V). Do the same test on the other test tab. Again, with key turned ON, your multimeter should read battery voltage. If one or both test tabs has no or little voltage, then you have found the problem.
Last edited by Maybe, maybe not; Aug 18, 2025 at 04:29 PM.
"10A fuse 23 is your main focus, but you can do the following voltage tests using a digital multimeter on both fuses.
You can buy an adequate digital multimeter for under $10 at Harbor Freight Tools.
Each fuse has two metal test tabs at the top. Set the multimeter to read DC voltage. Touch the red multimeter probe to one test tab and the black multimeter probe to body ground (e.g., one of the fuse box bolts). With key turned ON, your multimeter should read battery voltage (~12.6V). Do the same test on the other test tab. Again, with key turned ON, your multimeter should read battery voltage. If one or both test tabs has no or little voltage, then you have found the problem"
--------.
Thanks very much -
I used the multimeter I have, red probe to the test tab on the fuse and black probe grounded to one of the door hinge bolts. Got less than 5 volts, so I tried other fuses and got the same reading, so I figured the fuse is OK, I'm just not making a solid enough connection. Tested the multimeter on the battery itself and it showed the full 12. I may have to accept the possibility that I'm going to have to pull the radio.
Locate a different grounding point and then redo the voltage tests. Look for a metal frame under the dash.
You should also hook up a scan tool to see what BMW fault codes are retrieved.
Did two things - swapped out the fuse with a different 10A; problem persisted. Laid black probe on to negative terminal of battery, got the full 12V on the meter when I touched the red probe to the fuse. So yeah, nothing wrong with fuse or power. Note to self about using hinge bolts for ground.
I had already done a scan and got no codes. I may do it again to see if I missed something.
Seems like minimally you should recover a fault code for the radio.
The next step is what you possibly feared --> Remove radio and use the multimeter to determine whether battery voltage from fuse 23 reaches the radio connector.
Looks like the radio gets voltage from fuse 23 on a Red/Green wire.
Last edited by Maybe, maybe not; Aug 19, 2025 at 02:32 PM.
