Ok, I have a half size racing battery in my car after I finished my type-r motor swap and have had zero problems with it until a few weeks ago. I relocated my battery to my trunk and I drove my car without any problems for a month last season and off and on the beginning of this season. A few weeks ago, I get into my car and try to start it up and the battery is dead. I'm thinking "ok, no problem, I let it sit a little while and the battery's dead... I'll just jump it and charge it while I'm driving." Well I drove it about 20 min and when I got to my house, I turned it off and instantly tried to turn it back on again and it cranked over once, then gave up. Probably a dead battery right? Well the tricky thing is, 3 times out of the 12 or so times I've tried to start it since I began having this problem, it's fired right up no problem. This is where I'm confused. I"m thinking maybe I have a bad battery but that doesn't explain those 3 times that it started right up. I have a reading ohm meter and it measured 14.49 at the batter when it was running, 14.55 at the fuse box and 14.56 at the starter all while the car was running. So I turned off the car and checked the battery again, -12.65 and steady. Now since I've been writing this, the cars been outside sitting and not running. I checked it again and it reads -12.04. The car won't even turn over to start, it tries but just can't do it. Can anyone help me out?

 

What gauge wire are u running to the trunk?

 

If I remember correctly, its 4 gauge. I did a lot of research before moving the battery to the back and that was the the most recommended size to use.

 

if you did your research, then i guess thats fine.. now check the grounds, make sure you have a GOOD connection from the battery to the ground. and make sure the + has a good connection.

Also make sure the engine is getting a good ground.. try running another 4 gauge Ground wire from the frame to the Tranny side. make sure it has a good connection, and see what happens.. this may be the problem.. after this i dont know. the engine could not be getting enough ground to carry the power.

 

Hmm may be a long shot but maybe your starter solenoid is going out. The 9 times it didn't start, did it turn over or did it just click? If it was just clicking, sounds like your solenoid is going out. You can get a rebuild kit for like 15 bucks.

 

The common recommended size is 2 gauge. You might check the voltage of the battery while it is cranking. Compare that to the starter motor while cranking.

 

It might be 2 gauge wire, but I'm thinking its 4 gauge. When I turn the key it tries to turn over and then just sorta stops, sometimes the starter clicks, sometimes it doesnt.

 

Check your grounds for the battery and the engine.

 

The grounds from the head to the chassis and the tranny to the chassis are fine, I'll have to check the battery ground later

 

i had the same problem recently try and remove the dizzys harness the smaller one then charge the battery till full then connect it then since the dizzys disconnected try to turn it on the the car should just turn but wont start it should crank for 30 second if it doesnt if its like undre 10 seconds then u have a bad cell get new battery

 

Ok, I'm going to try that. But last night I was driving around a little and 3 out of the 4 times I had to start it, it started just fine. I checked all the grounds and there all in good connection... It doesn't sound like its my battery but maybe a loose connection but every connection I've checked is still rock solid. I'm confused

 

when ever you start your car you get a voltage drop of about 3-4volts. A good battery can support this but a bad battery cannot and the voltage will drop lower. The next time your car does not start connect your ohmeter to your battery and watch the drop when you turn the ignition switch. If your battery is at 12 volts and drops down to 7 volts or lower than the battery is no good. If the voltages drops to about 9 volts or so then its ok. And If you get no drop at all then you have a starter or ignition switch problem...

 

thanks for the advice, I'll try that the next time I go home