My 3800SC conversion has been running very well since the new engine was installed in 2010. Since moving to Oregon, odd problems have cropped up. First, the car developed a "clunk" sound that I have yet to find the source, secondly, little wiring problems crop up here and there and the last one could be potentially dangerous.

I drove down a long looping hill to the gas station to fill up and about halfway down the hill, the engine quit. My first clue was that I had very hard brake resistance (no vacuum). I tried restarting the engine while rolling in neutral (the shoulder is nonexistent on that road) and it was dead. No SES light, no turn signals, nothing. I still had momentum so I slowly rolled into the gas station lot, tried again to start the car and it started. I drove back home, parked it and drove my Grand Prix to town.

It acted as though there was no power anywhere through the ignition switch. I can't duplicate the problem and I am reluctant to drive the car any distance longer than a couple miles. What makes it inconvenient is that I have it for sale on craigslist and here in the mall. Another problem is that I am pretty much totally disabled and can't easily get under the car much less under the dash. I need to positively identify what is wrong before I take it to a garage. I have a newer steering column and ignition switch but I can't install it due to my physical limitations. Any ideas other than my ignition switch first impression?

First, make sure your battery connections are tight and that the cables are good. I've seen several cars experience this kind of mysterious shutting off only to discover loose or corroded battery cables.

Check the battery connection and the smaller ignition wire on the starter, make sure they are tight. You also mentioned a "clunk", I can't see how that is related but what does it sound like, where does it seem to come from and when do you hear the sound?

Thanks for your replies. The battery is new, the cables are new and tightly connected. I will try to drive the car onto some good steel ramps and see if the smaller ignition wire on the starter is tight but I tightened it myself in 2011. My wife will help me so things should go well with her supervision.

Tony, the "clunk" happens on severe acceleration and stopping. Sometimes, it happens with easy acceleration and easy stops. I haven't driven the car much because of my two recent surgeries but I don't recall the clunk happening recently or I ignore it. One thing I haven't mentioned is that the instrument cluster mount was very loose so I recently disassembled it, tightened all connections and now it is ok. I didn't do anything with the wiring that connects to the ignition switch because there was no need to do it.

I appreciate your replies--I have learned a lot from this forum and the helpful folks like you.

Richard

The clunk could be a bad motor mount....and that could pull on some wire connections, and loosen them up over time. You can test for this by putting the car in gear and rocking it forward and backward while watching the engine.

edit: engine off, handbrake off....automatics stay in 'park'. The engine should not move more than about an inch, and it should not twist at all.

[This message has been edited by Gall757 (edited 09-03-2014).]

Maybe NOT the" Battery connection". I had that problem with my wife's firebird, and I ended up Disconnecting, Cleaning with a Wire Brush and Tightening EVERY wire connection on the car (inc the starter). It fixed the Quitting problem, also Charges a whole lot better. Don't forget you Grounds.

Can the fusible link randomly disconnect and reconnect?

Thanks for your replies.

I was able to start the car and move it into the sun so I could have a good view of the wiring under the hood and while there, I checked everything. After jiggling wires, the car wouldn't start so I thought I was on the track but found nothing. Long story short, I am pretty sure I have a bad ground (Thanks, Captain America 2.5) under the dash because I found a black wire that was placed there by the guy who installed the engine and it was loose under the bolt holding the steering column. Of course, the car started immediately and I moved it so I could get my other car and my wife's car out of the garage.

After moving the errant ground to where it could make contact, the car not only started but the odd flickering of the dash lights, radio, etc stopped.

Getting under the dash wasn't good for my back so I'll find a local guy to get under the dash and tighten everything. Disability sucks big time.

Thanks to all who replied because you sent me to the right places to look. I will check mounts again for the clunk.

Richard

Edit: It was Lou who sent me to check grounds. Thanks Lou and the fusible links are alive and well.

[This message has been edited by starlightcoupe (edited 09-03-2014).]