so, i tried to start the car the other day, and it did start, but the guages pegged out and went back to normal after a second, and the idle went to about 2500 or so and stayed there for a little bit. then after it calmed down i drove away and everytime i would push in the clutch it would stay at 2500 rpms for a while then go back down. when i hit the brakes the headlights would dim as would the interior lights too. and when i turned on the highbeams the radio would cutout for a sec.

then i went home and it stayed parked for a day and when i went to start it i turned the key, and the radio came on and then antenna went up, and my phone charger light was on, so the batt was def not dead at all, but when i turned the key to start it, it clicked like it was a dead battery. when i hooked up the jumper cables to my batt (not hooked to other car yet) the power came back on and we went ahead and jumped it. it seemed like a freak occurance, but it wasnt...

i drove for a few hours home (was off at a friends college) and when i stopped at a food place for about 45 mins, i went to start the car and the radio came on and everything,but when i turned the key it clicked like the batt was dead. i just turned the key back off and tried again after a second and it started right up.

then i went to advance and had the batt and alt tested and they were both good. of course while i was there getting them tested nothing went wrong. the car started good and the lights didnt dim when i hit the brakes.

then i parked it for the night and when i went out this morning to start it it did the same thing. so i went and grabbed my mulimeter out of the truck and tested the battery, and it tested good. but, when i connected the test leads to the batt, i heard the power come back on inside the car(door was open). so i took off the leads and went to start it, and it wouldnt start, just clicked and power went off. so i went and put the leads back on the batt and it showed good voltage, and i heard the power come back on. this time i left the leads on the battery and went to start it, and it fired right up.

 

also, i got under the car, pulled out the battery followed the cables and theyre all good. no loose wires or anything.

 

Do you have an underdrive pulley installed? How about any aftermarket electronics (alarm, stereo, etc.)? I'm not sure what other components are in the path between the key and the starter. Perhaps, the keyswitch itself. Or maybe a flakey solenoid. THe lights dimming when you hit the brakes sounds like a grounding short. Perhaps chafed wiring in the harness. The intermittant problems are a devil to track down.

 

no underdrive pulley installed, no aftermarket electronics. alt tested good. as did the battery. ive checked all the grounds except the back of the heads, which i will do after work today when i have a chance.

 

I had a similar problem in an 1988 Mustang. Though, it only occured rarely. Once in a blue moon it wouldn't start. and on other rare occasion you'd be running fine and step on the brake pedal and sink the electrical system enough to stall the engine. I never did figure out what the cause was. And could never get it do that with any consistancy to show a mechanic the problem.