AustinJohn

I'm having a problem with my '85 this morning. Out at 6:30am for a nice drive in what passes for cool temps in Austin these summer months. Home, normal shut down but when attempted to head out again at 7:15am and turned ignition key, barely audible "click" and then no electrical power - no lights, no dash, no fuel pump and no start!

Checked battery (2 weeks "old" and fully charged) and searched Forum and found several suggestions (C100, fusible links, etc). Then at 8:30am I re-tried it and all lights worked normally but when I turned ignition key to "On" (not "Start"), all electrical power off again. I tried it again another two hours later but this time no "reset".

It's the "reset" that's puzzling me as this seems inconsistent with fusible links as I understand these work just like fuses and can't "reset", they're either good or bad. Next thought is the Starter Interrupt Relay in the Theft Deterrent System. According to Forum posts if the fusible link to the starter fails all power is lost and I wonder if the Starter Interrupt Relay has the same effect. But if that's it, I don't know how to reset the relay with no power.

Anyone have any ideas?

Thanks!

John

C409

..... My vote is corrosion - as in that powdery white stuff - in one or more or the wires at the positive battery terminal or the junction between the battery and firewall where the fusible links all congregate ... I have found them on occasion to be swollen with corrosion but still passing electrons ... I really doubt any involvement with the interrupt relay ... it controls the power to the starter solenoid only when the key is turned to the start position .............

AGENT 86

Poor connection at battery or juction block.

AustinJohn

Thanks for the good advice. I assume the area marked in pink in the thumbnail below (click to enlarge) is the infamous C100. Can one do all the cleaning from the engine side? John

nickpe

Clean alll your ground connections

AustinJohn

Thanks all. I cleaned C100, the battery connections AND grounds and all is well. John

C409

Not necessarily C100 ... but the jump start connector ... it is low and behind the battery , has a single stud sticking straight up and has a half dozen or so red wires attached ... most of those are fusible links ... check all of them closely ... its best to remove the battery for access ...