Hey all,

I'm new to the forums, and I apologize in advance for the lengthiness of this post, but I wanted to give as complete a context as possible.

A few weeks back, I cranked my car and got nothing after a short drive to the gas station. Battery was a few years old, and I hadn't been driving it for many long trips. I see it's covered in corosion. I clean that up and call my roadside assistance for a jump. It takes a minute, but it cranks. Dumb idea the first: I drive it back home instead of to an auto parts store to swap the battery. Next day it's dead, and the roadside assistance guy keeps infuriatingly insisting I turn on my lights and try to crank it without giving it a chance to charge. He keeps blathering that it's the starter. I tell him it's not but if he's gonna keep insisting it is because my lights turn on (and more importantly, he's probably got other jobs to get to--though he doesn't say that).

Upon closer inspection the next day with better light, I notice the positive cable has been eaten in half by corosion. So I bike to an auto parts store and buy a new one, swap that out, and wait for a neighbor with jumper cables to help me out since battery booster has gone to hell due to the ravages of time. Leave the cables on for a good 20+ minutes with his car running before I try to crank it. I hear a single click and nothing else.

"That sounds exactly like [our other neighbor]'s car when she needed a new starter," he says.

"Damn," I think, maybe that roadside assistance guy was right and I do need a new starter."

I look online and order the cheapest starter I can find that (allegedly) fits my model (dumb idea, the second, by the way). I get a buddy to help me swap it out when it finally gets here, since I didn't have the socket extensions I needed for the job. Get the old starter pulled. There's a problem though: the mounting plate doesn't line up. No biggie, says my mechanic buddy; he knowhea guy who fixes up old starters and alternators not too far from here. Repair guy trades me my (supposedly) busted starter (to be fair, it did sound like it was binding a little when he tested it) and my new one with the wrong mount bracket for a decent deal on a refurb he tests out in front of me (and gives me a 6-month warranty on it).

My buddy had to go to another job, but I watch some YouTube vids and install the new starter (luckily, that at least felt like a pretty easy job). Unfortunately, this meant I had to wait for a different friend with the socket extension I needed to swing by to help me tighten it down after I put it in.

We get the refurb starter in, hook the battery back up, charge it with jumpers for forever. We hear the solenoid try to get going, but the battery is just shot. He gives me a lift to an auto parts store to buy a new battery (which I should have just done in the first place).

Even though it's pitch black when we're putting the new battery in, somehow neither of us scratch our heads at the fact that the "negative" post is fitting awfully loosely, and the "positive" post is fitting awfully tight (dumb idea, the third). After all, why would the posts be in different positions on this battery? Weird that it's sparking so much when I reconnect it, and, oh god, why is my horn suddenly blaring? Better pull that horn relay. Huh, looks like we blew the 100-amp battery fuse. That's weird! (If you can't tell, yeah, AutoZone gave me the wrong damn battery, and as a result of that mixed with our hubris, I had reversed the polarity).

Swapped that out for the right battery and even put new terminals on my cables. I get the same voltage at the posts as the fuse box now, and my battery fuse isn't blowing when I connect the battery (which seems like an improvement). But it won't crank. All I get from the starter is a faint whirring noise. Gonna pull everything and double check the starter tomorrow and check all the rest of my fuses, but I'm worried that 100-amp fuse might not have been enough to keep my ECU from frying.

Any ideas what else I should be looking at or if it's possible for me to swap out my ECU for one from the junkyard (even given the preceding yarn)?

I've been outta work for months due to COVID, wanting to get a new job (which I unfortunately can't do without a car where I live--at least not the job I'm trying to get). Any advice that doesn't involve me towing my car to an auto shop and robbing a bank to pay for the repairs or just giving up on automobiles and jobs entirely and sneakily hopping the next freight train to embrace a more freewheeling hobo life is appreciated.

 

If the battery fuse is blown and replaced and other components don't work, then also check under-hood fuses no. 47 (20A), no. 48 (20A), no. 49 (15A), and no. 50 (30A). -- These other fuses protect other circuits that also receive direct battery power.

If still not, you will need to go abck through and check all the fuses one by one and see if anything else got shocked.

 

You're my hero! Thank you!

 

So, update on the car:

Went back to square one and checked my starter installation after none of the fuses were bad (something I should have checked much sooner) with some daylight so I could see what I was looking at and noticed the power to the solenoid must've come loose when I swapped the battery. Had to pull the starter to get to where the wire had fallen to (and, just my luck, the power connection on my refurb starter sheered when I was loosening the nut 🤦‍♂️, so I had to swap that one out for another refurb). But as soon as I got the new starter installed with the power cables seated properly, it cranked right up!

So relieved I didn't fry the ECU!

 

Great you got it going! That says something about the car if it can take and survive a polarity reversal. Best of luck finding work - many of us are in the same boat.