hey, so get this, after driving for about a min my check engine light comes on and when that happens my tach dies. and my car doesnt want to charge its self even with the new alternator. i checked my codes and they didnt show anything of significance, ie. emissions solenoids i removed, aux ports that i disabled, variable dynamic chamber that i disabled, thats it. the day b4 it rained pretty bad and my rear window has a leak. i think it might be due to maybe water damage but i pulled up my carpet near the ecu and it didnt seem wet. ill remove it and check inside when i get the chance. anyways i was just wondering if any of you guys had any clue what it could be. thanks for any input.

 

voltage when running?

 

The ECU is protecting itself by disabling the Trail coil assy and therefore also the tach signal. Battery/alternator output is tooooooo low. Put a digital meter on it as suggested above. The alternator output post.

 

u are correct about that a hailers. i have a digital read out of my voltages coming from my cig lighter. the check engine light comes one when the voltages drop somewhere below 12 volts and my car will start to buck at higher rpms.its a brand new one, it made 1 volts difference. it starts out at 12.6v then will continue to drop all the way to 11.3v as i drive it by then it cant start under its own power. thats why ive been charging it with my batt charger b4 i go anywhere. it could only be the wiring. but ill check directly in my engine bay too. damn electrical gremlins!

 

problem solved. alternator outputting 14v.
what had happened i guess was bc the u joints on my driveshaft being broken caused enough excessive vibrations to partially undue a large ground wire. tightened that up and now my problems are a thing of the past. thanks hailers.