[hemitheus]

i have an 82 and an 83 with the same problem. the brights work fine. the headlights dont.

I replaced the dimmer in the 82. didnt fix anything.

any advice? hoping this is a known issue

 

[ToxicDoc]

burned out filaments?

 

[jerseybud]

Some other guys with this issue found it to be the headlight switch

 

[modelcitizen]

Do you mean the hi beams work but lo beams don't-on both trucks? This could be as simple as lo beams are burned out on both trucks. Does the hi beam indicator in dash light up with hi beams on?

Do you have a test light? Ground it to battery negative terminal,turn headlights on lo beam and probe the back of  headlight connector for voltage. If you have voltage on one lo beam connector,check the one on other side of truck. If you have juice in both connectors,replace both headlamps. Check to be sure the ground wire from battery negative terminal to radiator support is present and clean/tight.

If you don't have voltage at lo beam socket,go inside truck,ground test light,turn headlights on and backprobe dimmer switch connector. You should have voltage on two of three terminals at all times. One terminal is power incoming from headlight switch,there will be power at one of the other terminals and when you push dimmer switch power will be had from the third terminal. 
If you have working hi beams and you have voltage switching from one terminal to the other but no lo beams,trace lo beam wire back to headlights,it will have an open somewhere between dimmer switch and headlamp. Be sure you don't have burned out lo beams on both bulbs,have seen people tearing into wiring looking for the problem and burned out bulbs were the problem. This applies to both trucks.

 

[DODGEBOYS]

all power go,s thru the dimmer switch  , so if the highs work then either the dimmer switch is bad or the bulbs are burnt , OLNY two choices

 

[hemitheus]

no low beams. high only. yes the blue indicator works.

I will buy another dimmer. perhaps the one i got wass faulty. we will see.

 

[dodge82273]

all power go,s thru the dimmer switch , so if the highs work then either the dimmer switch is bad or the bulbs are burnt , OLNY two choices

agreed . start looking from dimmer to bulbs it's on that end ...

 

[DODGEBOYS]

very rare and even rarer too have two trucks do it but but a burnt connection in the bulk head connector [ its more common on the older trucks 1972 to 1980]