Dimming

I was sitting in line at arbys earlier, I didn't have any music playing which is rare for me.. it was totally silent and I started rolling up my windows, when the dome light dimmed, rpm's dropped 100, and I got a slight vibration.. I've seen things like this happen on overloaded circuits in houses and what not, but this seemed a bit strange.. any ideas

altenator? though that wouldn't explain the shaking.

It happens to me too...I have no idea why, that is the beauty of aging electronics

May be the window motor drawing a ton of current. A window motor does take a good amount, however old unlubricated tracks/motors will take more power and at an idle in gear your alternator is spinning the slowest and has the least ability to provide the extra power needed.

Try to get a multimeter or scan on the car and check the voltage while operating the window. Most likely that would be the culprit. Lubricating the track and checking the motor may help the issue.

mine does it too. give it a little gas while rolling them up and it goes away. they just draw a lot of power at idle. ill have to try cleaning the tracks and motor, thanks for the tip Bill.

I did the voltage booster mod last month. Although I haven't had a chance to test everything, so far there seems to be less dimming and idle variation.

I also, I used the PowrTuner to raise my idle RPMs a tiny bit. I've found the car vibrates less and feels more alive after doing this.

Another possible tip. The motors on the B'ville have a threaded area where you can insert a zerk (grease fitting) and give them a little lubrication in the worm gear area. This has been found to be helpful.

Not sure on the Riv motors though.

some ideas:

- push the alternator fan with your thumb, with the engine OFF, and see if you can move it. Maybe your tensioner has weakened over time - this is why some suggest chnaging it with the belt change.

- find out what the actual cold-cranking capacity of your battery is. A GM dealer, or Sears, or I think AutoZone, or others have the needed test equipment. My dealer will run this test for free if you are in the shop for any other service (even just an oil change). You will likely find that your battery's current capacity is below the spec. When the ligts dim, you're drawing more current than the battery and alternator can put out at a given voltage - so voltage drops under the load and the lights dim.

- remote chance that you have bad grounds. Find them and clean them. You can smear alittle conductive grease (such as no-al-ox, you can get it pretty cheap at Home Depot) on the terminals and bolts when you reassemble. If you use the conductive grease, they won't corrode so fast again, and maybe not at all.

- what BillBoost wrote about the window current draw - re-read that. Being a GM car, a replacement for the window motor, if needed, should not be too tough or too expensive if you are handy. It could even be that the connections are corroded a bit and now have fairly high resistance, and so cleaning them will reduce current draw. Bill's recommendation (lube the tracks and check the motor) works for me, in addition to the above.

Happy wrenching

Albertj

My car does that a little bit as well. Might be a Riviera thing....

Personal experience. When my riv did this dimming thing, it was the battery. It had more than enough juice to start the car BUT capacity hd diminished (no surprise, it was ~10 years old).

A volo I had did it, one time it was a loose alt belt and another time the alt brushes had given out. That one was fun, I had it repaired on a sunday afternoon by a, umm... very conservative ex-Navy shipboard technician. He is a *character* and he really knows his stuff. Has an interesting business in an area even more rural (arkport) than I live in. Is 'open' 24 hours a day by appointment, and guarded by a feral cat. Anyway, he will repair (and I believe this after seeing him work on that Bosh alternator for the Volvo) any motor/generator that he can properly open and either has or can make parts for.

Albertj

yup i experince the same thing, sometimes when im going at a slow speed and turn, when i press the gas a little to move up, and when i let off the gas.

well at least it's not just me lol..

Quote :

When my riv did this dimming thing, it was the battery

my battery is brand new, it's an optima gelcore, so it might not be the same case, but like bill said the windows just draw alot of current. aaron was that the caspers booster?

Mine does the same thing, almost feels like the motor is going to stop.