Strange start issues

[RG92535i]

Hi, I'm new to group and could really use some of your expert help and experiences. My 1992 535i will not not start unless I jump car from under the hood at jump block. Battery is charged. Alternator is working. I have to connect jumper cables from battery under back seat to front compartment.
Bought car recently and I'm not sure what all is connected and operative under back seat (like alarm and old cell phone components. I cleaned and checked bat cables Any ideas as to what might be inhibiting power from getting to starter from bat?

[cschollum]

80amp fusable link under rear seat will have gone bad, cracked or fused, its located next to the battery under the rear seat, small back box 2 inch long, hinged lid

[RG92535i]

80amp fusable link under rear seat will have gone bad, cracked or fused, its located next to the battery under the rear seat, small back box 2 inch long, hinged lid

Is it possible that fusible link is bad and is not effecting other things?
Windows, sunroof, and others seem to still be working. Thanks,

[angrypancake]

bump.

[genphreak]

Hi, I'm new to group and could really use some of your expert help and experiences. My 1992 535i will not not start unless I jump car from under the hood at jump block. Battery is charged. Alternator is working. I have to connect jumper cables from battery under back seat to front compartment.
Bought car recently and I'm not sure what all is connected and operative under back seat (like alarm and old cell phone components. I cleaned and checked bat cables Any ideas as to what might be inhibiting power from getting to starter from bat?

Something works at 15V, but not at 12V. I'd check the starter relay (swap the starter motor relay as these are well known to die anyway, some peeps carry spares even) but you can jumper the contacts of the starter relay to see if you can get it to crank independently of the other car. Maybe the starter solenoid if not, the starter itselfor then you get more and more obscue checking things like the key switch, wiring and the relevant modules inside the ebox... Nick

[angrypancake]

i'm having an issue where i have to jump the car from the battery. once i turn it off though it wont restart unless i jump it again. no suggested alternator problems, stereo, interior lights, etc all work with no problems, no battery lights or anything. i'm thinking the fusible link?