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[twenty8mate]

Hey guys, I have a 1988 535i. I'm having issues getting it started. I have a brand new battery but im getting no power when i turn the key. However, when i jumpstart it, the car holds power on its own fine. Im sure theres many reasons why this could be happening, so any ideas would help, thanks

[flyboyx]

what do you mean by jump start? hooking up jumper cables from another car to your battery or do you mean "bump start" where you push the car and someone lets out the clutch? your description isn't useful in making any sort of determination as to what is going on.

i would probably start by replacing the main relay. this is probably a 1" white cube that is mounted on the firewall or maybe the driver's side inner fender. there is probably a piece of black plastic covering it up and it is probably in a bank of three relays. go find a couple used ones at the junk yard and just switch them out.

[saturnv7890]

If it works fine when you hit it with some jumper cables, I'd run a volt meter across your battery to make sure its charged. And if it is, I'd clean the battery terminals really good.




If it starts fine with a BUMP start, you've got a starter issue.
Possibilities:
-Bad corroded connections on starter (cleaning is free!) (check out all connections including strap that goes from solenoid to motor, and that motor grounds nicely to block)
-Bad corroded connections in ignition switch (rare)
-Bad starter solenoid, hit it while trying to start. If it starts when you hit the solenoid, go buy a new starter
-Bad main relay or contacts (if your horn works, temporarily swap out main with horn relay)

[dougie30]

He means jump start. When we jump it, it runs fine. When we jump it and let it run to charge the battery it won't charge it, inturn making not start under its own power

Sounds like the battery right? Nope brand new battery so I'm assuming it could be the main relay too.

[jdirty]

Alternator? I would check the brushes/contacts.

[saturnv7890]

Did you hit the battery with a volt meter? And you cleaned the battery terminals? The ones on the "car side" too?

[South26]

Does the alt light come on when you turn the car on? If the alt light is burned out on the instrument cluster it will not allow the alt to work.


Andy