Battery connected with reversed polarity - now what?
Battery connected with reversed polarity - now what?
I just got a 1995 Mazda MX3, 4 cylinder.
Long story short the replacement battery's posts were on the same side as the one I took out but the polarity was reversed and I connected it wrong.
Now nothing lights up when the key is turned but the battery is installed correctly and has 12V plus.
I'm guessing it's fried, not just some little fuses blown.
Anybody know how to go about fixing this?
Long story short the replacement battery's posts were on the same side as the one I took out but the polarity was reversed and I connected it wrong.
Now nothing lights up when the key is turned but the battery is installed correctly and has 12V plus.
I'm guessing it's fried, not just some little fuses blown.
Anybody know how to go about fixing this?
- Ryan
- Senior Member
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- antispam: ~SPAM*SUX~
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Re: Battery connected with reversed polarity - now what?
Check the main fuse.
If all your fuses are good, then you probably let the magic smoke out of the ECM and will need a replacement.
If all your fuses are good, then you probably let the magic smoke out of the ECM and will need a replacement.
Now with Moderator power!
Black '93 BP RS - wrecked, parted, scrapped.
Green GS - Sold.
Black GS - Summer DD/Race car - Fancy KLZE
Red GS - K8-ATX -> MTX-KLDE - Frakencar. Scrapped
White GS - Rusty. Parts. Scrapped
1997 BMW M3 - my summer baby
2002 BMW 325Xi - sold
2003 Forester Xti - EJ20K swapped.
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Black '93 BP RS - wrecked, parted, scrapped.
Green GS - Sold.
Black GS - Summer DD/Race car - Fancy KLZE
Red GS - K8-ATX -> MTX-KLDE - Frakencar. Scrapped
White GS - Rusty. Parts. Scrapped
1997 BMW M3 - my summer baby
2002 BMW 325Xi - sold
2003 Forester Xti - EJ20K swapped.
Feedback
Re: Battery connected with reversed polarity - now what?
So am i looking for a 4cyl ECU at the pic n pull as well. 

2004 Subaru WRX Silver, stage 2, minty interior.
2002 Subaru WRX Blue, SOLD (best E test numbers I've ever seen)
94 MX-6. Sold
92 GS KLZE 5 Speed
96 GS 5 speed, KLZE, Sold
95 GS Minty Shape Sold
92 GS Sold
92 GS Parts Car scrapped.
Feedback viewtopic.php?f=37&t=66348" onclick="window.open(this.href);return false;
7477th member.
I know you believe that you understand what you think I said but I'm sure you realize that what you heard is not what I meant.
2002 Subaru WRX Blue, SOLD (best E test numbers I've ever seen)
94 MX-6. Sold
92 GS KLZE 5 Speed
96 GS 5 speed, KLZE, Sold
95 GS Minty Shape Sold
92 GS Sold
92 GS Parts Car scrapped.
Feedback viewtopic.php?f=37&t=66348" onclick="window.open(this.href);return false;
7477th member.
I know you believe that you understand what you think I said but I'm sure you realize that what you heard is not what I meant.
Re: Battery connected with reversed polarity - now what?
thanks for the replies.
OK - there's an 80 amp fuse blown - but it's the only fuse that wont come out of the housing.
Is it supposed to come out?
All the others do.
Or are you supposed to remove the entire fuse-housing module?
The blown 80amp fuse is black in color.
OK - there's an 80 amp fuse blown - but it's the only fuse that wont come out of the housing.
Is it supposed to come out?
All the others do.
Or are you supposed to remove the entire fuse-housing module?
The blown 80amp fuse is black in color.
- Ryan
- Senior Member
- Posts: 7199
- Joined: April 7th, 2008, 1:06 pm
- antispam: ~SPAM*SUX~
- Location: Manitoba
Re: Battery connected with reversed polarity - now what?
Its bolted on. Just look around, you'll figure it out.
Now with Moderator power!
Black '93 BP RS - wrecked, parted, scrapped.
Green GS - Sold.
Black GS - Summer DD/Race car - Fancy KLZE
Red GS - K8-ATX -> MTX-KLDE - Frakencar. Scrapped
White GS - Rusty. Parts. Scrapped
1997 BMW M3 - my summer baby
2002 BMW 325Xi - sold
2003 Forester Xti - EJ20K swapped.
Feedback
Black '93 BP RS - wrecked, parted, scrapped.
Green GS - Sold.
Black GS - Summer DD/Race car - Fancy KLZE
Red GS - K8-ATX -> MTX-KLDE - Frakencar. Scrapped
White GS - Rusty. Parts. Scrapped
1997 BMW M3 - my summer baby
2002 BMW 325Xi - sold
2003 Forester Xti - EJ20K swapped.
Feedback
Re: Battery connected with reversed polarity - now what?
Got it.
Have to go get a socket set now.
I hope its just the fuse but I doubt it.
I'll swap that out and report back.
Wish me luck ...

Have to go get a socket set now.
I hope its just the fuse but I doubt it.
I'll swap that out and report back.
Wish me luck ...

Re: Battery connected with reversed polarity - now what?
I swapped out the main fuse and it started right up - wuhu!

thanks for the help.

thanks for the help.
Re: Battery connected with reversed polarity - now what?
Next time, 'martin up'. 

2004 Subaru WRX Silver, stage 2, minty interior.
2002 Subaru WRX Blue, SOLD (best E test numbers I've ever seen)
94 MX-6. Sold
92 GS KLZE 5 Speed
96 GS 5 speed, KLZE, Sold
95 GS Minty Shape Sold
92 GS Sold
92 GS Parts Car scrapped.
Feedback viewtopic.php?f=37&t=66348" onclick="window.open(this.href);return false;
7477th member.
I know you believe that you understand what you think I said but I'm sure you realize that what you heard is not what I meant.
2002 Subaru WRX Blue, SOLD (best E test numbers I've ever seen)
94 MX-6. Sold
92 GS KLZE 5 Speed
96 GS 5 speed, KLZE, Sold
95 GS Minty Shape Sold
92 GS Sold
92 GS Parts Car scrapped.
Feedback viewtopic.php?f=37&t=66348" onclick="window.open(this.href);return false;
7477th member.
I know you believe that you understand what you think I said but I'm sure you realize that what you heard is not what I meant.
- Ryan
- Senior Member
- Posts: 7199
- Joined: April 7th, 2008, 1:06 pm
- antispam: ~SPAM*SUX~
- Location: Manitoba
Re: Battery connected with reversed polarity - now what?
you must now paypal everyone who posted in this thread $10 because we saved your a--!
Just kidding! Glad it was so simple for ya. Troubleshooting the whole system at once is probably the worst job
Just kidding! Glad it was so simple for ya. Troubleshooting the whole system at once is probably the worst job

Now with Moderator power!
Black '93 BP RS - wrecked, parted, scrapped.
Green GS - Sold.
Black GS - Summer DD/Race car - Fancy KLZE
Red GS - K8-ATX -> MTX-KLDE - Frakencar. Scrapped
White GS - Rusty. Parts. Scrapped
1997 BMW M3 - my summer baby
2002 BMW 325Xi - sold
2003 Forester Xti - EJ20K swapped.
Feedback
Black '93 BP RS - wrecked, parted, scrapped.
Green GS - Sold.
Black GS - Summer DD/Race car - Fancy KLZE
Red GS - K8-ATX -> MTX-KLDE - Frakencar. Scrapped
White GS - Rusty. Parts. Scrapped
1997 BMW M3 - my summer baby
2002 BMW 325Xi - sold
2003 Forester Xti - EJ20K swapped.
Feedback
Re: Battery connected with reversed polarity - now what?
yeah - that was my fear - diagnosing the entire electrical system, replacing part after expensive part and it still not working.
i spent all morning driving around like mario andretti.
vroom!
it's handling qualities are vastly superior to my last car, a jurassic-era 1500kg, V8 powered Bonneville.
like a cigarette boat vs the forrestal.
well, not quite, but you get the point.

i spent all morning driving around like mario andretti.
vroom!
it's handling qualities are vastly superior to my last car, a jurassic-era 1500kg, V8 powered Bonneville.
like a cigarette boat vs the forrestal.
well, not quite, but you get the point.
