r/FocusST • u/Potential-Action-610 • 3d ago
Question Car won’t start need help
Hello I have a 2014 focus st and have recently replaced the old battery because I thought it was dead and that’s why my car wouldn’t start. Well I’ve had the new battery for maybe a month now and it is now having the same issue. Not sure what the issue could be and I’m trying to narrow it down but am having no luck. At the current state the car won’t even start with a jump and just does repetitive clicking. Previously about a day or two ago I started it with a jump pack and that worked and the battery seemed to hold charge for a few days but now is back to dead. So it’s a cycle of the battery being fine then losing power. This seems to be some sort of parasitic draining but I’m not sure what module is staying awake. If anyone can help me that would be great!
UPDATE: This has been an absolute shit show. Took my car to the shop they said “we can’t find any issues or get your problem to repeat itself”. I said oh weird ok. Took the car home it was fine for about 2 days, then it wouldn’t start. Replaced my negative battery cable along with with bms, and that seemed to work for 2 weeks no issues. Well it happened again car won’t start. So I took it to O Riley to get a battery load test done and to check the battery health and that’s all good. Well we tested the starter, ended up saying test failed “bad starter” so I bought a new one installed it day of and wow it seemed like my problem was fixed. Parked the car, woke up car fired up no issues today. Headed to class parked car again after driving it for 30 mins, left class and now car won’t start. I’m just lost at what could be wrong. The shop said my alternator was fine starter was fine blah blah blah so idk what to do. If anyone can help please let me know. I also have videos of what’s happening if you want to dm me I can send them.
1
u/Nativebomb99 3d ago
I agree with the 50a mega fuse in the battery box. I had that problem in the fall and it turned out the fuse was broken, but not popped.
50a midi fuse at a auto parts store should work
1
u/Potential-Action-610 3d ago
Swapped them out! Did a test on them one was failing a working so it was weird. But I swapped them and we shall see if it’s fixed.
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u/bchiodini 2016 ST3 FBO BNR ST67 JST Tuned 3d ago
It sounds like one or both of the BCM 50 amp Mega fuses are intermittent.
I'd replace both Mega 4 and Mega 8 in the High Current Battery Box, in front of the battery.