My Mustang Thinks It's A Lawn Mower?

[89PonyExpress]

I've been having a crazy problem with my '89 LX the past few weeks. It's not a problem that happens constantly, but it is one that bothers me and makes me wonder exactly what's going on.

The car starts fine, runs fine, and this problem happens only when my rear end leaves the drivers seat. The car completely stalls out. The radio loses power, and I can hear what I assume is the fuel pump relay clicking. Note that this problem doesn't happen everytime I leave the seat, but it does happen often enough to where it gets rather annoying to me. (Expecially if I leave the car and want to leave it running.)

I replaced the relay under the drivers seat thinking that was the problem. The problem still persists though. Is there a ground near/under the seat that would kill all power to the engine? Or am I completely looking in the wrong area to solve my problem? When the car loses power it gets it right back. The car starts back immediatley after it quits.

It's a true 5.0 car with a 5 speed transmission if that bit of information helps any.

 

[jrichker]

There was a FREE recall on Ford ignition switches. They overheat and sometimes catch fire. That burns up the steering column and sometimes the car interior. Since this is very old information, you may not be able to get the switch replaced for free anymore. The auto parts stores sell the switches for $13-$15.

Some of the symptoms of ignition switch problems are things that don’t work or are intermittent like radio, wipers or heater.

Saleen0679 was nice enough to dig this up for us awhile back: Replace a 1979-1993 Ignition Switch Assembly

 

[89PonyExpress]

Very interesting article. That's a fix I'll definatley be doing. That's one thing I did fail to mention though. The car will start. (Sometimes) without the key. A secret I've kept very safe around friends. I suppose with the lumbar seats there are some terminals that eventually make their way into the switch for power. I just found it awkward that I can move a certain way in my seat and I just lost all power. I thought their might have been a ground under the carpeting around the seat, but then again I haven't had the seat out of the car yet.

 

[91TwighlightGT]

I don't believe there is a ground underneath the seat. I am wondering if there are some wires that are pinched underneath the carpet, like maybe the seat has been out before and when it was reinstalled the wires were pinched.

 

[89PonyExpress]

I done a little experimenting this morning. (At least until it started raining again.) I started the engine, and began to get up. The car nearly stalled but as I sat down in the seat again it "refired." Without me having to restart it with the key. I then got out of the car, and literally shook the seat. All corners, even got under the seat and jumbled every wire I could see to see if I could get the car to stall out. To my suprise, I couldn't get it to happen. I sat back down into the seat and began to fumble around with the key switch. Much to my surprise, I could replicate what usually happens with the very minute turn of the switch backwards. It doesn't click at all, and if I turn the key very slightly forward once again I regain power.


So I'll definatley be replacing the ignition switch per his suggestion above. I just hope that's all of my problem. I just don't understand how it can be triggered through the seat as well unless it's probable that some of those contacts make their way into the switch. Which I guess makes a lot of sense.

 

[89PonyExpress]

Update:

I replaced the electrical switch in the car this morning, and wow. The minute I took out the trim around the steering column, I had parts of the switch falling in the floor. It finally came out in around three pieces so yea, it was definatly worth the $15 it cost me.

After I installed it, I started the car and tried to replicate what has been happening here in the driveway. (I have yet to take it on a test drive) but I couldn't get the problematic stall to happen again, so I am going out on a limb and guessing this solved my problem. I also noticed something else though, before this install I could turn the switch back to ACC, and I had no radio. Now I do! I always thought the previous owner had it wired up wrong, but that wasn't the case.

jrichker Thanks for the great link. Very informative information I had no clue about.

 

[dgollem]

Sounds like you got it fixed. Wonder if you were pulling yourself up a little by the steering wheel when you got out of the car, just enough to affect the bad switch?

 

[89PonyExpress]

Very probable. I really have never paid that much attention to how I got out of the car, but I will now.