Naughty park avenue

My Denver daughterhas a 1998 Buick Park Avenue with 117k miles,no rust, very good miles, and hopefully another 100k miles but it is badly misbehaving.

Three “experts” have looked at it but solved nothing except the ringing of their cash register.

The car suddenly looses electrical power with a warning by having the voltage swing wildly to a low of 10.4 volts to a high of 14 volts. This voltage swing is then soon followed with the loss of all displays on the dash. A second or two after that the power again comes back on. The frequency of this failure is increasing to as often as four times in twenty minutes.

The first “expert” replaced the battery and alternator and charged approx $800.00.

The second “expert” claimed he did a load test and drove it for a week and found nothing. They did not provide results for either test but did charege $54.00.I believe they did nothing because the car failed four times in twenty minutes while driving it home.

The third “expert” found two wires that appeared to be chewed by mice so these were butt spliced, but no improvement has been gained.

SO WHAT IS THE CAUSE??? We look for the obvious possible loose connection but could find none.Is the problem mechanical in nature (a broken or loose wire) or electronic in nature (a resister, transistor, or surge monitor of some sort)as a component in an electronic circuit,or those devilish nymphs in the Denver area?



Is this a digital dash? Did they check to power to the dash display?

Yes, it is digital. I’ll follow up to see if they checked the power to the dash. What are they looking for, a fuse, loose connection…?

I’d look for a loose connection first. Perhaps wiggling wires the next time it loses power would be a help. Also, there is likely a voltage regulator for the instrument cluster. Worth checking. If the regulator is integrated into the dashboard circuitry, you may have to replace the whole instrument cluster. A junkyard would be a good source for one of these.

The problem could also be a loos firewall connector. GM uses a 2-piece connector, usually located near the brake booster, with the outside half held onto the inside half by a single bolt in the middle. They coat it with a weatherproofing goop, but sometimes the conenctions go bad. Afterall, it is only 12 volts.

There are several GM Service Bulletins around the kind of problems the car is experiencing. Of particular interest is Service bulletin no. 02-06-03-008 August 2002, and Service bulletin no. 03-06-04-012 January 2003. I saw these through my public library’s online service called ARRC (Auto Repair Reference Center). You can, too (maybe). Ask a librarian.

The Buick is a big electrical power consumer. It can draw 125 amps with a few things on (read the bulletin). The alternator can not supply this power until the car is moving at 15 mph, and higher. Until then, the battery is carrying the (heavy) load.
At speed (above 15 mph), as the alternator’s output can increase, it’s output is “ramped up” (controlled in steps) by the engine computer. Someone checking the electrical system should check that the control voltage from the engine computer increases in smooth, even, steps. [Don’t you just hate it when things get technical?]