Happy Holidays, having electrical problems with my 89 Civic. I turn on the heater and the light go dim. Turn off the heater light are bright. Turn the brights on and the radio cuts out. Then I turned of the car and tried starting it again and I have no power at all. I have checked the fuses and everything seems good. Checked the battery and it tested fine. Any suggestion?

 

Don't double post.

You will need a voltmeter. Leave the key off but turn the headlight switch on to establish a load on the system. (The rest here assumes that the headlights don't come on.) Measure voltage between the two battery posts, on the lead posts that are part of the battery. If approximately zero, the battery is run down and/or bad. If > 12 volts, continue. Put one lead on the minus battery post and the other on a grounded part of the body. Should be very close to zero. If you find a voltage difference, the ground circuit is open, usually it is a bad connection at the battery terminal. Do the same thing on the positive side, testing from the + battery post to the main fuses in the fuse box near the battery. Check that the fuses are not blown by measuring for a voltage difference across the fuse.

 

TY mK378, Sorry about the double post.. The battery test good! As a matter of fact I put a brand new battery in. I had a feeling that I may have a open or loose connection either on the positive or negative side. Is there a certain area in the fuse box near the battery I should concentrate on? Thank for the help!

 

Get a voltmeter, find out where you are losing the voltage.