connected battery wrong, fried wire, what else?

[scottmi]

hope this is correct forum!
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stupidly connected battery reversed polarity yesterday after installing new battery cables. put the battery back in the car (the wrong way) and hooked it up and....smoking heavy red wire from the battery to the starter relay.

disconnected, cleaned it up, just appeared to be melted sheath, no fuses appear blown...

To test system, taped up the wire that melted and reconnected another, good, fully charged battery the right way. no spark when connecting ground lead, no lights when open door, no dash lights when turn to the "on" position...

when turned to crank starter, a couple dash lights lit and something got a little smoky somewhere (starter?) but no cranking of starter.

both terminals disconnected now. troubleshooting to begin.

Any ideas? what (all) did I fry?!

 

[natenkiki2004]

Did you check the main fuses in the power distribution block?

 

[scottmi]

yes.. and fuses under steering wheel. all those look good. Fusible links in the harness are my next check, then starter solenoid, and of course, the main computer chip..

 

[94explorerEB]

Not to change the topic but where did you get your lift?

 

[Explorin'VA]

The alternator could be fried for one. That might be what smoked when you tried to crank it.

 

[scottmi]

Not to change the topic but where did you get your lift?

a place in Kirkland, WA that has long since moved/gone away..

 

[scottmi]

The alternator could be fried for one. That might be what smoked when you tried to crank it.

Yeah, I figure it might be. but then again, is not what is keeping dash dark in the 'on' position. heck, can run a car with a dead alternator...just doesn't charge.

still need to get under and check more out. this week.
such a drag.

 

[BKennedy]

If the fusable link did its job, its fried. It should be visible as two melted wires at the end of the red wire coming from the battery to the starter solenoid.

Did you try to start it with the cables reversed?

 

[the_don]

i would start by replacing the fuseable links, put a voltage meter on all of the fuses, replace the rectifier, then try to start it.

 

[scottmi]

thanks BKennedy and the_don- TODAY I need to get under and do some checking...
no, did not try to start with reversed. no way! wire was hot and smoking before could even tighten batt cable down. just what the power could have reached in "off" position.

good tip on checking fuses with meter. all looked good, but something is open somewhere.

rectifier... any way to test existing one? also, that would not prevent dash from working, or starting car would it? part of charging circuit...only?

 

[scottmi]

Running again! though the fuses all looked good, under the steering wheel two of them failed the continuity test with a multimeter so replaced those...
also took out starter, alternator, and cable assembly from starter post to alternator which includes the fusible link(s). Cable was good. Local NAPA tested starter, was good. Tested alternator.. bad "light circuit" and probably whole rectifier, but lucky me, was a new alternator from a couple months ago so had one one hand and warranty replacement, free. Yay! got home, put it back together, and ... all is good. Car running again as it should. Now washed, and ready to join the family again. ;-)

All ended up not so bad. No dollars spent to fix as spare fuses were on hand, and alternator replaced under warranty. You can bet I won't EVER make that mistake again!

so.. lessons learned:
1/ always double-check and confirm your polarity when placing a battery back in the car.
2/ these new-fangled fuses can fail and still look good. test them with a meter.
3/ alternator electronics (rectifier) will fail given any opportunity at all.

also..
4/ plan on an oil/filter change if you replace your explorer battery cables. The chassis ground point (on 91-94 at least) is located right behind the filter.

and
5/ when replacing your alternator, check the alternator pulley.. the replacement may be a different size. If so, keep/use the one you had from old alternator to ensure belts stay proper tension. My initial 'new alternator' had a different (much smaller) size pulley on it (I had kept the old one, luckily). With the smaller diameter the belt just did not get quite tight enough and idler pulley often squealed on startup. Horribly! When took alt back out and ended up with new one, I had the original pulley with me. The second 'new' alternator had yet another size pulley... so swapped in the original while at the store and now, with new alt installed with original size pulley: no squeaking belts! So much better. My teenage son, who was -mortified- with the squeal, might even allow himself to be seen in the truck again..

Thanks all for the suggestions! I was so disgusted with myself and damn stupid mistake it was hard to get out to follow-up on diagnosing, but the continuity testing of fuses, and simple removal and testing of alternator and fusible link cables resolved it...in an afternoon, including trip to shop. In the end, not so bad.

 

[natenkiki2004]

Sounds like you got away pretty lucky, however I'd imagine the engineers would have accounted for this happening once or twice. Good to know it wasn't anything catastrophic or expensive to replace

 

[the_don]

Great to hear! before i would call it "done", i would do i KOEO test to double check all of the sensors, then take it out on a dirt/gravel road and check the ABS system.