Possessed car.

I have a 1998 GP GTP with 81,000 and about a month ago i went out as normal to start up my car and the car would not start. i sounded a lot like the battery went dead. the clock was reset on my aftermarket radio and it just did the normal clicking. tried to jump it and then the gauges went crazy. the jumped irratically and still would not start. the way the gauges went really concerned me and so i no longer thought that the problem was with the battery. i went ahead and bought a brand new battery just to rule out some causes and the problem then got worse. the gauges still went crazy (the gas hand, tach, and odometer). they would jump from zero to all and bounce in between for a while until you pulled the key out. but the key would not come out sometimes it would get locked in the ignition. to me it felt as if the car thought i was stealing it. it even started beeping with the key out very slow and sick sounding in about 15 second intervals. so i put the old battery back in and left the battery unhooked for about 20 minutes thinking that it would possibly reset itself. it finally started perfect. turned the car off and still started everytime. thought the problem was fixed.

then last week while going 65 down the interstate i rolled up my window and the driving center and radio clicked off and then the car died on me while driving. got it to the side of the road and the gauges then went crazy again and the car did not want to start. so i played with it for a little while and turned the key to ACC ON and OFF several times and slowly got the power back to the car and it started as if nothing was wrong. So i did get angry and got on it a little bit and the low trac kicked in and killed the car again. it was as if the car could not handle the load of everything running and rolling the window and the low trac just drained all the power. i then had the alternator check to be sure and it was perfect (charging at 14.4) no problems there. I did have a cold air intake on the car and since you have to take the computer out of the air box i thought that maybe it was getting some depris or getting cold so i put the factory airbox back on the car and nothing really changed.

Last night i was going home and hit a little spot of ice on the driveway (i was going 5mph) and the ABS kicked in and the car died again. tried to turn the hazzards on so nobody would hit me and it buzzed and would not come on. i did have dome lights though. i tried to start it and it was as if the battery was dead i had dim head and dome lights, it clicked when you tried to start it, and no power to any dash lights. Went to get help from boyfriend and still would not start. then i got in and turned the ignition to the on position and slowly things started coming on. so as things came on (the air, radio, etc.) i would turn them off and then would get more power. so i turned the car off pulled the key out and tried it again, had almost 100% back, and then pulled key out and then put it back in and it started and everything worked with no trouble.

I get more and more confused as weird things happen to this car. I am taking it to a GM dealer to have them run a complete diagnostic check on it and see what they have to say. I just was wandering if anyone else had similar problems, what it is, and how to fix it. It has done little things that would take to long to write about. Please somebody help me.

Your problem sounds like a classic ignition switch and harness problem. One or more contacts are either arced out, sticking or open. The dealer will probably come up with a similar diagnosis because they will make money on the labor and have the right equipment and diagnostic procedures to troubleshoot it. The part itself is around $100 GM list.

I was thinking that maybe the ingnition was faulty. i was also maybe thinking that the Body Control Module could be at fault. do you think that could be possible or the ignition would be more probable? Could i do the ingition myself or would it be better to have a GM mechanic do the job.

I was thinking that maybe the ingnition was faulty. i was also maybe thinking that the Body Control Module could be at fault. do you think that could be possible or the ignition would be more probable? Could i do the ingition myself or would it be better to have a GM mechanic do the job.

Although a BCM module could be suspect your symptoms does not indicate it is a BCM problem. The ignition switch is the most probable culprit based on the symptoms. I have a procedure for changing out the switch and it can be done DIY but it is a real PITA so you would be better served by having a mechanic do it. Not necessarily the dealer but a general mechanic who has proven GM experience. Good luck!

thank you so much for your help. i should have joined this site a long time ago.

Just to reassure you, I agree with Bnaylor, as you have every symptom of a bad ignition switch.

The first thought I had was the battery terminal screws were loose. I had this exact same situation happen in a company vehicle, and when I went to jump it, I decided to check the terminal screws and the + side was not even finger-tight. Tightening the screws fixed the problem. Since you changed the battery, the screws are probably tight. Something else easy to check and fix is the ground for the battery. I'm not familiar with the 1998, but there should be a wire coming from the battery (-) terminal running to the body of the car. Check to see if this connection is tight, and is not all corroded. These are just some things to rule out before spending the big bucks on new ignition switch. Another thing to check is the alternator. If it is not charging battery properly, even the new one will soon die. Somebody more familiar can correct me, but it should be putting out about +14v DC when the engine is running. Good luck.

Whoops, I just re-read your post. Looks like you already checked the alternator.

I'm not familiar with the 1998, but there should be a wire coming from the battery (-) terminal running to the body of the car. Check to see if this connection is tight, and is not all corroded.

On '97 and up Grand Prixs the main system ground which includes the battery negative terminates at the engine-transmission grounding stud and not the body. Several ground wires are located at that stud. It is located on the rear of the engine where tranny is bolted on, radiator side. FYI.

just checking in to let everybody now what the problem ended up being. In case somebody else has this problem. the + battery terminal was corroded. it did not appear it from the looks of the battery post, but the corrosion was inside the wire. when putting on a new side post terminal the wire was so green and powdery i can see why she was shuting off going down the road. i never thought that this would make the car lose all power because on most vehicles you only need the battery to start the car not to keep it running that is the purpose in an alternator. no on the GP evedently. on these cars the computer system to run by the battery that is why it was dying. anyway got a new battery again and new side terminal and the problem is fixed.

You are right about the car running only alternator when engine is on, most of the time, but when you have too much load (i.e. a few accesories on and roling down a window:wink:) that is when the battery steps in and provides the temporary assistance...

and there is a ground on the body right next to the battery, under the fuse box. ZZP has this listed under their mod page:

http://www.zzperformance.com/grand_prix/articles1.php?id=34

that is what i would have checked first. loose grounds and/or a bad terminal connection on the positive side could also have caused the same problems. since they are cheaper and easier than the ignition switch or the bcm, it is a good idea to always check them first. i clean mine no less then 3-4 times a year. its like dad always used to say..."start with the easy things..."