Hey guys im new here. i own an 85 rx-7 i bought in june. Im having problems with the battery draining, my dad says it might be the starter, what do you guys think? :rice:

 

no it's not the starter, the only way it could be the starter if it was stuck running. Your alternator however can kill your battery if one of the internal diodes goes bad. Here is a quick way to find the cause. All you need is an ordinary test light.

Keep all doors closed and key out of ignition. disconnect negative battery teminal. connect one end of testlight to the neg. battery, and the other to the neg. cable(a link between battery and cable). If the test ligh lights up, then you have a short, if it does not light up not a short, may be an internal battey short.

If it does light up pull one fuse at a time till the light goes out(with doors closed!!) this will isolate what circuit has the short then you just have to trace that one circuit. If after pulling the fuses light still there , try

disconnecting the alternator and see if light goes away

 

Another thing to look at is the sterio.If you have a aftermarket deck in the car make sure that the illumination and the deck shuts down when you turn the key off.My friend had a amp installed in his and his battery kept dying because the shop that installed it didn't hook up the remote power wire to a switched power but to a hot wire under the dash instead.

 

first thing before you go out and spend any money...check and make sure the cables are very tight

also check and make sure they are not dirty where they connect to the post



Shortly after I got my car I couldn't keep it charged because of the posts being coroded



could also just be a bad battery...how old is the thing?

should have a date on it

 

ive just replaced the batery. anywy the starter was dead so i had it rebuilt, im not sure if its the problem, but im going to find out tommorrow.

 

Similar to the test light idea, get a multimeter and do the same thing, connecting it between your positive terminal and the wire. This way you can actually see how much drain there is on the battery.

You should see a small drain on the display, from the stereo memory settings, etc, If you want I can contact my RAC battery-selling friends and find out for ya.

You can tell anyway if its a rediculous amount like more than 2 amps, you've got a problem.

 

Ok, I checked with my mate, anything more than 50 mA is a potential problem. Up to 20 milliamps is about normal, allowing for immobilizers and stereo, etc. Apparently a few people can have problems, but because they drive their car everyday, never notice it due to their battery being charged when they drive. But they go away for a week holiday and come back to a dead battery.