I have a 87 rx7 I just recently bought. I have had no problems with this car it has 152000 miles on it with a re manufactured motor in it since 100000 miles. Now for the problem it has no power I open the doors no lights come on and if I try to start it nothing. So I thought it was the battery and went and bout a new one. Still nothing but if I put my jumper cables on it and connect them to my truck it starts just fine then after idleing for about 10 min it just stalls. Then the no power thing happens again. Any help is appreciated

 

Did you buy a NEW battery or just a different battery? If new, did you charge it before installation?
The stalling after 10 minutes suggests it's running directly off of battery power and your alternator might be bad.
If you can get it running long enough to get it to a local auto parts chain-store, most will test the system (for free). That might tell you what's going on.

 

Yes I have done that. And it is a brand new battery. The part that has me dripped is the no power. If I pull the battery I have in the rx7 it will start my 81 f250 without a problem. But I pu it in the car and all of a sudden no power until I just hook cables up to and all I have to do is just touch em no clamping them down our nothing. And then I have power

 

Below the engine fuse box lies a black plug that joins two fairly thick Black wires together. Check each side of the plug/connector for voltage. Don't disconnect the plug to check as one wire will have constant voltage and passes this constant voltage onto the other wire (again, don't disconnect the connector ). No key necessary as the voltage is constant for the wires are powered up by the battery. Doing this will help to diagnose your problem and in the process help to eliminate some things.



Look at the plug highlighted by the red arrow.

 

Ty will check that later on today