still chasing gremlins in the car.. now when I turn off the ignition the check engine light comes on real dim and will go off if hit the brake pedal ... turn the key on and it goes back to bright.. scanned it and have a 53 code (ecm sees voltage more than 17 volts).. the car runs ok but will not idle if on brakes and idles faster than normal about 2500 while in gear.. if you put it in neutral idle will slow till it dies..also car floods bad from cold start.. anyone have any ides?? I am thinking maybe ecm is crapping out..

 

what is your voltage at the battery with car running?

 

13-13.5 .. has rebuilt alternator from a 03 burb.. never shows any voltage spikes.. with headlights and defrost was down to 12 .. thing that has me wondering is why the check engine light is staying after key is turned off on but real dim.. noticed today when you get on gas hard there is a whining noise coming from computer area.. not a vacuum leak noise gets louder and faster as depress pedal

 

IF (big IF) your voltmeter is accurate, you have electrical system problems. (Anything from a slipping alternator belt, to a partially-failed alternator or regulator, to excess resistance in the vehicle wiring harness. A failed battery might also cause this, although it's somewhat unlikely.)

I'd expect 14.2 or close with the engine running, never below 13 even with headlights, HVAC fan on high, wipers on high, etc.

 

13.5V MINIMUM with all those accessories on (engine running). Either bad alternator, bad battery or both. Possible it is wired incorrectly, I would think '03 the voltage regulator would be controlled by the PCM, but I'm not familiar with anything past the late 90s. Either way, sort out this before continuing with any further troubleshooting.

 

ok .. I have put alternator from my s10 blazer on car just to make sure.. 13.8 v now.. check engine light still dim when ignition is off and key out.. noticed when hit brakes at idle car will quit flooding out so checked for vacuum problem even blocked off brake boost line and line to vacuum switch on brake pedal.. found none.. unhooked the the electric switch on brake pedal and idles smooth.. pink and purple wire on it.. also check engine light goes out now.. plug it back up and light burns dim when shut off..what is the cause ??? but now car will not crank at all.. code 53 can be vats from what I have read so I assume it has taken a crap.. gonna bypass it tmmr and see .. think I might try computer from my formula as well .. thnx for info so far this thing is getting close to becoming a engine swap candidate but hate to because it is completely factory.. even radio is original

 

get battery tested then check battery connections at battery, battery to block ground and ecm grounds at back of head (passenger iirc). its almost like something is back feeding the check engine lights (two wires melted together) get a wiring diagram you will need to trace it out.

dont have wiring diagram infront of me but isnt pink/blk + purple for tc solenoid? perhaps solenoid is bad or getting fed 12v all the time (should only have 12v with ignition on).

 

have tested battery .. it is new and good.. checked cable connections .. I have not checked ground on back of head but I will.. brake lights work ..unplugging those wires do not effect them at all.. have wiring diagrams and service manuals on the car.. I do not have them at moment either but I believe the plug I unplug has something to do with cruise control module.. look in the bottom left corner of this http://austinthirdgen.org/mkportal/m..._continued.gif and maybe you can tell me if I am correct
thank you...

 

brake switch should have 2 connections, one for brake lights and another for torque converter lockup. cruise control has a separte switch that is accuated by the brake pedal. in the case of my caprice this switch also has a vacuum line that comes oit of it. im betting the problem is with your tc circuit. my guess is a wire has. melted to your check engine light somewhere under the dash and is feeding power probably not a great connection hence the dimness. what puzzles me is the tc circuit should only have power with key on. had something similar with my '89 caprice the ecu ground from aldl plug almost to the ecu had melted and made contact with a bunch of other wires caused for some weird dash operation. someone had most likely fed power to the wrong aldl pin at somepoint.

 

yes the switch with the vacuum line it the one I am disconnecting .. I did not get around to messing with it today .. still will not crank so gonna have to bypass security

 

check cruise servo or plug vac line that goes to switch. dont know why this would cause a dim check engine light with car off though. perhaps your ignition switch needs to be adjusted or replaced.

 

ok finally got around to bypassing security and have car running again.. I have blocked off the vacuum line to the brake switch.. did that when I thought might be a vacuum issue.. do not think it is the switch because the light only burns when the electric connection is connected to the vacuum switch on brake pedal.. changed ecm today and nothing changed .. all same symptoms.. have not seen anything like this.. no one else I talk to has either.. could the cruise control module be a issue?? pretty sure that is the plug .. could it be flooding the engine somehow?/ thnx

 

https://www.thirdgen.org/forums/elec...ight-stay.html

found this just now .. gonna trace alternator wires and double check alternator .. but my battery isn't running down like his and my light goes out when unplug wires. so I am not thinking will be my issue