Cadillac Repair: car electronics gone wild!, serial data line, speedo needle


Question
QUESTION: I replaced the water pump on my 95 eldorado touring coupe this weekend and when i reconnected the battery the key was off and the fan (for the a/c heater in car) started running, the speedo needle going crazy 0 to max repeatedly, and the display on. start car, run it come back turn car off remove key from ignition and the display stays on like the car ignition is still on (run position) i can turn display off but I will still have a dead battery unless I disconnect a cable. could it be the computer? If it is where would it be located, any help will be appreciated.

ANSWER: Your most likely problem is that you forgot to reattach a GROUND WIRE that you removed when you replaced the pump. What you need to do is check the computer for CODESin order to determine which ground wire or other wire or wires you forgot to hook back up.

You will need pictures and wiring locations which can be obtained by E-mailing: onlineautohelp@msn.com

---------- FOLLOW-UP ----------

QUESTION: sorry for the delay there is no ground wire that was disconnected, I did however retrieve the codes as follows current To67, To77, and To73  History Po52, Po94, P109, and Io52 thanks

Answer
T067 is a faulty STOP/Cruise brake switch. Do you have STOP lights when you step on the brake pedal ?>

T073 is a fault in the PCM computer Traction control system interface.

T077 = is a compuuter (PCM) serial data line malfunction.

The other codes are history codes which are of no concern right now.

Due to this many codes you need to e-mail: onlineautohelp@msn.com and ask him this question.