Reversed polarities when replacing battery, interior lights, power door locks, radio stopped working and will not start?

CARRI BURNS

MEMBER
2017 MITSUBISHI OUTLANDER SPORT
2.4L
4 CYL
2WD
AUTOMATIC
92,000 MILES

My battery kept draining over a 3-day period, I kept having to get it jumped off, so I went to AutoZone to have them check the battery, alternator, starter and they couldn't check past the battery because it was bad. We got a new battery and my husband hooked it up backwards, the horn started going off, I got out of the car and that's when I noticed it was hooked up backwards. After that, interior lights, power door locks and radio would not work and of course the vehicle wouldn't start. We replaced the battery, replaced the fuse on the positive battery terminal because it was blown and the fuse for the radio. Everything started working again but the vehicle still won't turn over. We have unhooked the battery and let it sit, tried different things with the key fob but we weren't sure if we were doing the right thing because we couldn't find very much information on it, switched around some of the relays and nothing will work. When you try to start it you just hear a slight click noise. If you could help, I would greatly appreciate it. The Mitsubishi dealership wouldn't even give me any advice over the phone they just wanted me to bring it in, but there isn't a dealership in my town so I would have to have it towed over fifty miles.

Friday, July 22nd, 2022 AT 9:45 AM

1 Reply

JACOBANDNICKOLAS

MECHANIC
110,101 POSTS

Hi,

There are two fusible links between the battery and the starter motor. It is fusible link 24 in the engine compartment relay box. If you haven't, check it first. Also, there are two fusible links on the battery that are required for the starter to work.

Next, there is a 10-amp fuse in the interior fuse box that is what energizes the starter relay to start the engine. Check that too. In addition to checking the fuses, make sure there is power to and from them. Here is a link that explains how that is done. Note: It is important to check for power at the fuse regardless of its condition. Especially on this fuse.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Next is the starter relay. I don't feel that would have been damaged, but here is a link explaining how to test one.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

I attached the starter circuit wiring schematic below, so you have a reference.

Let me know what you find or if you have other questions.

Take care,

Joe

See pics below. Note: the wiring schematic was one page. I had to cut it in half to make it readable for you. Also, just for a test, will it start in neutral?

Images (Click to make bigger)