[86GTStang306]

Battery Reads 11.8 Volts

Car wont start unless its jumped off, It will run and I turn the head lights on they get brighter as I rev the car up then after a minute or so the lights go off and the car starts running like shit then it cuts off, battery & alt are new and i had the alt tested and was it okay....

also do 86 mustang have external voltage regulators?

[fogged306]

What do you mean the battery is charging the starter? Does the starter engage without you turning the key?

[86GTStang306]

i just read what i typed and i dont even fucking understand what i was trying to say so let me fix it hahaah

[86GTStang306]

there lol

[sk1nner]

sounds like you have bad cables IMO. get new power and ground cables. get a cable that grounds the engine block to the chassis. make sure all contact points are good and clean/paint free. if the alt and battery are " good" thats all it can be. that or the alt/battery may be on its way out, but still reads "good".

[gripthenboost]

is your alternator good? start the car disconnect the battery and see if it stay on.

[86GTStang306]

I did start the car and unhook the battery and it died

[fogged306]

I don't know if the 86s are external or not and I'm too lazy to look, but if it is, you're on the right track asking about it because it's most likely your issue. Also, don't remove the battery cables while the car is running. The alternator doesn't put out a smooth DC output. It's an AC signal with the bottom half of the sine wave cut off so it basically pulses DC current. It's not the best thing for your onboard electronics that want true DC current and you can damage them this way. The battery acts like a buffer to stop that from happening.

[86GTStang306]

Originally Posted by fogged306 I don't know if the 86s are external or not and I'm too lazy to look, but if it is, you're on the right track asking about it because it's most likely your issue. Also, don't remove the battery cables while the car is running. The alternator doesn't put out a smooth DC output. It's an AC signal with the bottom half of the sine wave cut off so it basically pulses DC current. It's not the best thing for your onboard electronics that want true DC current and you can damage them this way. The battery acts like a buffer to stop that from happening.

oh cmon go see if it has a external regulator it would help me alot lol i dont wanna bum a ride to my car to fix something that isnt there to be fixed

[95tbirdv8]

you should get the battery charged somewhere. then put it on and see if it drives. my car with a bad alternator lasted about 30 minutes running right off the battery. if it runs, then you know its the harness to the alternator or the cables going towards the starter solenoid or battery, im not familiar with the 86

[Tony Silva]

From what I've researched, the 1986 and newer mustangs do NOT have an external Regulators. If it did it would be in the engine compartment, foward of the passenger side shock tower...bolted to the side of the engine bay. I've posted a few days ago about my car having the same problems ie: good battery/good alternator but still no charge. Basically all I did was cut the 2 fat black/white stripe wires a few inches out of the back of the alternator and run new wires to 100 amp fuse and then connect to the battery positive post. So far, every thing is charging fine. My mustang is all stock with the exception of a sound system consisting of 700 watts Orion amplifiers and Borla exhaust! My problem was the fusible links were bad. It was much easier to change out the wires rather than replacing the fuse link.