1985 Dodge Ram

1985 DODGE RAM
87,000 MILES • V8 • 2WD • AUTOMATIC
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DANDREN
  • MEMBER
  • 1 POST
the headlight dashlights cargo light and radio all dim in and out while i am driving but are fine while i am parked and idleing. What could be the problem
Mar 23, 2009 at 11:23 AM
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RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
Get your charging system checked out-The alternator could be on its way out or the battery is not taking it-get both load tested.
Mar 23, 2009 at 11:33 AM
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CARADIODOC
  • CAR REPAIR CONTRIBUTOR
  • 34,309 POSTS
Also check the battery cables. Watch the alternator gauge on the dash when this happens. If the needle drops when the lights dim, you could have worn brushes in the alternator. You have way too few miles to expect bad brushes already unless you drive in dusty conditions a lot. I can copy and paste the directions on testing this system. It's very easy, and this is a very reliable system. The brushes can often be replaced without removing the alternator from the engine.

While watching the brightness of the headlights, try wiggling the wiring harnesses under the hood while the engine is running. In particular, suspect corroded pins in connectors. Also, look at the voltage regulator on the firewall. It's about three by four inches, and 3/4" thick, and usually silver or black. It has a triangular connector with a blue and a green wire. Check the two mounting bolts to be sure they're tight. The mechanical connection is one of the electrical connections. The charging system will be dead if the regulator is not bolted solidly to the firewall.

caradiodoc
Mar 25, 2009 at 4:04 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.