Alternator trouble

Asked by Jan 27, 2017 at 08:53 PM about the 1985 GMC C/K 10

Question type: Maintenance & Repair

I have a 85 gmc and I've tested the alternator
battery and starter.  All are good.  When I drive and
come to a stop light the interior lights and
headlights dim but when I speed back up all lights
are bright again.  Any ideas where to start?

1 Answer

66,305

Some "flairing" of the lights in relationship to engine speed is normal on a non-computer controlled vehicle. If it's excessive there's a problem. Such as a bad alternator drive belt or serpentine belt tensioner, if equipped. HTH. -Jim

Your Answer

Add photo

Related Questions

  • trouble on my back-up lamp gmc serra sl 1996 2 answers

    trouble on my back-up lamp

    1996 GMC Sierra 1500 C1500 SL Standard Cab LB

    -

    Maintenance & Repair

  • Transmission trouble 3 answers

    I have a 1994GMC Vandura 3500 with a 5.7 L V-8, and automatic trans. Just today on the way home, the transmission started jerking very hard shifting between 1st and second gear. Anyone have any idea...

    GMC Vandura

    -

    Maintenance & Repair

  • Transmission Trouble 1 answer

    1997 k150 4l60e transmission. Well i did a fluch fill and filte ron my jasper rebuilt trans and now i get really high rpmflares between 2nd and 3rd gear and same between 3rd and 4th also i blew out th...

    GMC

    -

    Maintenance & Repair

  • Driving trouble 1 answer

    my car does not accelerate very well I will run very high RPMs with very sluggish acceleration. Stay my engine light came on and told me if my mass airflow sensor could this be the problem or coul...

    1997 GMC Jimmy 4 Dr SLE 4WD SUV

    -

    Maintenance & Repair

  • tranny trouble 3 answers

    I got a 1994 gmc 1500 4x4 with a 350 auto. The tranny loses overdrive and third gear after about 30 mins of driving it i will have first, second and reverse, but if i let it sit for about 15 mins it...

    1994 GMC Sierra 1500 K1500 SL 4WD Extended Cab SB

    -

    General

C/K 10

Looking for a Used C/K 10 in your area?

CarGurus has thousands of nationwide listings and the tools to find you a great deal.

Postal Code:

Shortcuts

Search GMC C/K 10 Questions

GMC C/K 10 Experts

#1 tennisshoes
tennisshoes
Reputation 30
#2 gearheadnard321
gearheadnard321
Reputation 20
#3 AskTrannyMan
AskTrannyMan
Reputation 10
View All

Related Models For Sale

Used Ford F-150
296 Great Deals out of 8,121 listings starting at $2,499
Used Ford Mustang
1,334 listings starting at $5,980
Used Chevrolet Corvette
661 listings starting at $11,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.