Possessed Bonneville

[Guest]

I am posting the link to this topic that was in our local paper today.  I could no download it from the Times Colonist but found it on Google.  We seem to have quite a few people here that like a good challenge.

https://theusatribune.com/2020/08/under-the-hood-the-strange-case-of-the-possessed-bonneville/

[joe_padavano]

Editor: "Oh, just grab a random photo of a Bonneville to go with this story..."  🙄

 

[Rusty_OToole]

I've never had a car that was possessed but my buddy had one that was repossessed.

[JACK M]

All of my cars are possessed.

By me.

Oh yea, and the are all one owner cars.

 

This is an interesting story, glad it got figured out, Whod'a thunk.

Edited September 1, 2020 by JACK M (see edit history)

[Graham Man]

Yes the story is not nearly as interesting with the car that had the problem...1988 Pontiac Bonneville SSE, this car could have a million electrical gremlins.  The Bonneville pictured could have ....well burnt points...a bad dimmer bulb... bad plug wire...I think that is it.

 

[Pfeil]

On 9/2/2020 at 9:46 AM, Graham Man said:

Yes the story is not nearly as interesting with the car that had the problem...1988 Pontiac Bonneville SSE, this car could have a million electrical gremlins.  The Bonneville pictured could have ....well burnt points...a bad dimmer bulb... bad plug wire...I think that is it.

 

You forgot to mention a bad transistor ignition.

[8E45E]

On 9/1/2020 at 12:10 PM, JACK M said:

All of my cars are possessed.

By me.

Oh yea, and the are all one owner cars.

 

This is an interesting story, glad it got figured out, Whod'a thunk.

It turns out the gentleman lived in a mansion-like home with a very long driveway lined with very large trees. As we came up the driveway the CD player and A/C system went nuts! I looked up at the open sunroof and flickering shadows and it hit me: I had never driven with the sunroof open. I laid a shop towel across the top of the steering wheel/steering column junction and the symptoms absolutely subsided during a dozen or more driveway trips. Apparently the flickering ambient light was reaching the photo transistors and was mimicking various button commands.

 

 Years ago, when I worked at the service station, we had a 1976 Continental Mark IV with an unusual problem.  On a nicer spring day, when the sun was shining, but still cool enough outside to have the heater on 'low', the customer complained the A/C would suddenly come on full blast for about 30 seconds to a minute at random, and then revert back to the low heat, setting.  This car had the fully automatic temperature control (aka 'Comfortron' in GM language).  Finally we narrowed it down to only doing this when the sun was out in the sky, and making the dark blue paint warm to the touch despite having to wear a coat or a sweater outside, and only on right turns.😜  After a month or so of diagnosing the fault, it was the body shop who replaced the left front fender who left one of the three thermistors hanging loose; the one located behind the kickpanel near the driver's feet.  Whenever the owner made a right hand turn, the thermistor would swing free, and make contact with the warm fender, and send the signal for the A/C to come on, and then once the turn was made, the thermistor would hang in the air again, and properly resume sensing ambient air temperature.

 

Craig