Heres the deal, on a 89 EA82 it had been sitting and the batterys dead, I jump started it  and it ran good, shut it off, battery wont hold a charge ,with key off I go to jump it again but hook up the jumper cables backwards, the clamp made a good spark, I realized what I did and unhooked it, it was only like 3 seconds, now I hook it up correct and nothing works, it wont turn over theres no power to do the power windows, so what should I do? what did I ruin?

Check fusible links and fuses. 

+1 fusible links

Years ago I did this to my RX.

Besides frying some of the fusible links, I borked a few gauges in the inst panel.

+1 Unfortunately it's possible you fried something in the ECU as well. It takes less than a second to do that. If it doesn't run after you replace the blown fusible link..... well.... bummer.

Blown fusible links, I had a blown ECU once due to the same thing.  both easy fixes.

thanks guys , hope its not the ECU

I  think you will be okay. If I remember correctly there is a protection diode inside the ECU that helps stop damage for this kind of thing.

 

If you don't know where the links are they are in the small plastic box mounted on the coolant reservoir. You most likely blew out the main black link.

The FL's are hard to inspect within their intact clothlike covers. I have heard of one mechanical shop stuffing something and hoping to claim on dealer warranty, so the workers allegedly did their best to fry the ECU by shorting out terminals - could not kill it ! I also had a FL fail mid flight at 60mph due to corrosion and it had to happen some time. Car almost would not run, the behind the dash stunk of burnt out capacitors etc, indicator bulb filaments spat out to melt into the insides of the bulbs due to voltage spike/surge that ocured as corroded FL made contact again ECU survived. Guess who has an 89 EA82 mpfi ECU  ?

 

Maybe you only ruined a battery ? Try another first !

Edited September 14, 201312 yr by jono

When links burn out they burn in the middle of the link. While it can be hard By bending them it is easy to feel and see the difference between a good one and a blown link.