Hi i have a 1991 toyota pickup 2wd 3.0 6 cylinder and i recently installed the battery wrong. positive on negative and negative on positive ( reversed polarity) I saw some sparks on the battery terminal but no smoke coming from anywhere. I checked the fuses and sure enough i blew the 80 amp alt fuse and the 15 efi which i have replaced no problem. I also checked the fuse panel on driver side interior and they all look good. now with the battery hooked up correctly i put my key in and all i get is a ignition buzz to let me know the key is in and the door open, i get the instrument panel to light up temporarily but once i turn the key to start i get nothing and the electronics stop working, the stereo does not work either nor the ac blower fan, i am able to use the dome light still which is not very bright but still working. im not sure where to go from here. does this sound like a relay? how can i tell? i am new to electrical problems so any tips would be appreciated. thank you

 

The first thing you need to check is how much voltage the battery has.
Should be around 12,6 volts.

 

Like ksti says^^^
Next only to our senses, the multi-meter is the most important electrical troubleshooting tool. Electrical troubleshooting without one is like going to war without ammo.

A problem well-stated is a problem almost solved.

It would also help if you organized your problem description:

Clearly list all systems that work (i.e., tail lights work? Headlights work? Dash backlight work?):
1)
2)
3)
.
.
.
Clearly list all systems that do not work:
1)
2)
3)
.
.
.
.

 

You just touched the last battery cable to the battery ??

Just how long was it on there??

I wonder if it took out fusible links if it has any.

Time to break out the Meter

 

The battery checks out at about 12.6 volts i went and got a new one just incase.
i had the battery connected backwards for probably about 10 minutes before i realized it and yes i tried to start the vehicle a couple times like that.

current situation.....

headlights are working
dome light working
i get ignition sound to let me know key is in when door open

When i put the key in and turn on electronics....

blower fan will turn on
stereo is working after i replaced 10 amp in the back of it
cigarette lighter is working

​​​​​when i turn key to turn start engine blower fan will die all electronics cut out and all i hear is a slight whining sound

​
The starter? I should also mention before i screwed everything up with reversing the polaritys. The reason i bought a new battery is because truck wouldnt start just made a rapid click sound

also another update truck just started up once and then i turned it off to see if i could start it again but no just a slight whiny sound

 

Thanks for the orderly description! But...

what did you do with the new battery?

 

The fact your Truck is not a smoldering hunk of metal is really interesting .



How did you not get major Arcing when you connected the last cable ??

I would look if any of the ground cables are melted off or cooked inside the insulation

 

OR... the short killed the battery internally.
O.P. still did not say if he charged and/or installed the new battery.

 

Yes agreed, I think he said battery was hooked up for 10 minutes.
Their is got to more to the story.

 

the battery was bought at walmart i took it back and exchanged it just incase it was bad this was before i bought a multimeter.

but i do have a final update for this, hooking up the battery wrong blew my fuses .and the whiny and click sound i heard was due to corrosion on my battery terminal connectors. i had cleaned them with a wire brush but it apparently was not enough. there was only a small amount of juice making it through but not enough to start the truck and i had to replace them now it starts right up. so case closed. thanks to everyone that jumped on to help

 

Wow in this case corroded battery terminals were a Good Thing!!

 

Glad you got it figured out
There you go. That's why I always stress: Connections should have bare, shiny metal tightly touching bare, shiny metal.