What is causing this electrical problem?

FREELIZARD

MEMBER
1985 NISSAN 300ZX
97,000 MILES

I accidently connected the battery terminals incorrectly - saw sparks and some smoke from the passenger side area near the battery and fuse box there. Started the car and it ran fine but had no lights or dash(digital).
I did have power to the windows but nothing else. Checked fuses and could see none that looked fried or burned.

revved up engine and all electrical sytems came back on - then would not work after shutting off - tightening battery cables and restarting a second time

so is it a fuse after all - or a relay or alternator?

5 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Check and test the alternator, battery and all the fusible links-start here

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Tuesday, October 4th, 2011 AT 11:46 PM

FREELIZARD

MEMBER
3 POSTS

I know the battery is good as it's practically new and was fully charged and out of the car before I did this

I'm thinking alternator problem at this time - or the fusible links

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Wednesday, October 5th, 2011 AT 12:00 AM

RASMATAZ

MECHANIC
75,992 POSTS

Lets do some testing on that areas and also the ignition switch

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Wednesday, October 5th, 2011 AT 12:02 AM

FREELIZARD

MEMBER
3 POSTS

Well I checked all the fusible links and relays - except for the horn, didn't want to come off easily so I didn't force it, and all the fuses by the drivers side - replaced one 10 amp for the dash ac controls. And still no running lights or dash but I do have power to the windows, drivers seat and mirrors. Car starts fine and runs even with loose battery cables so I'm thinking the alternator is ok - any way to test is without removal?

Behind and to the rear of the fusible link box there is a small recess with what look like two other fuse-relay type objects - I did not mess with them - yet, could they be the problem? One is lime green the other black ( 85 300Zx non turbo ) what wires I could see in the area looked fine - no scorching evident

gonna check chiltons again. Any other ideas on where to check fuses, relays etc?

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Thursday, October 6th, 2011 AT 10:22 PM

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

You may need to check the headlight switch itself. Power for both problem areas goes through the switch.

As far as the alt, most parts stores will test it for free. If you want to test it, do this. Using a volt meter, check the voltage the battery produces by itself. It should be 12+ volts. Start the engine and retest. The voltage should be around 14 volts.