1998 chevrolet S10 P/U 4WD extended cab when the headlights are switched from lo to high beam the head lights function fine but I have no indication on the instrument cluster light? The bulb is good

Power to the left and right headlamp assemblies is supplied by the Lighting Control Module. Power leaves the module, passes through the multi-function switch, and depending on the switch position, is routed to the LO or HI beam side of the headlight assemblies. When routed to the HI beam side, the HI beam indicator in the instrument cluster is additionally supplied with voltage from the same source of power. Because the low beams work, we can know that the power source (Lighting Control Module) is operating properly and that power is successfully passing from the module to the switch. This leaves the following areas as potential failure points for the high beam circuit; multi-function switch (bad HI beam switch contact), multi-function switch to headlight assembly wiring (open circuit), or the high beam element inside both headlamp assemblies. It would be odd (although not impossible) for both headlight assemblies to go bad at once, therefore the multi-function (combination) switch would be my #1 suspect. You can read more about combination switch issues here: https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-combination-switch-assembly

http://www.ehow.com/how_5262885_change-out-dimmer-switch-camaro.html


this should help.

It can be issue with headlight switch,but as its already been replaced.Try disconnecting high beam headlight wiring from headlight assembly and reconnect direct external wire from headlight switch to headlight assembly,then by switch see if headlight is getting off and turning on or not.
See below related help links,similar to your issue.Click the link below:----
Only high beams work but head lights not working on Ford F350?

http://howtobyme.blogspot.com/2011/11/only-high-beams-work-but-head-lights.html

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Only high beams working on GMC Savana?---------- High beams stopped working but headlights still work? http://howtobyme.blogspot.com/2011/11/highbeams-stopped-working-but.html
---------- • Working of Headlight switch? ----------

• Both headlight bulbs blow together? ----------

• Car headlight bulbs don't last long?
------------ Only one head light works on 2001 Dodge Caravan? http://howtobyme.blogspot.com/2011/11/only-one-head-light-works-on-2001-dodge.html

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these will help.
Thanks.

wiggle the hi-lo beam switch lever, if you can get them to blink, the switch may be bad.

take a look at the dash ground wire located next to the right of ebrake release handle. if the bole holding the ground wire is loose, which was quite common it will cause all kinds of feed back problems, like described in the comments section to your question.

Is this both the high beams and low beams that do not work ?

If you checked all 3 fuses with a meter ( with the headlamp in Low position for both low beam fuses or in high for the high beam fuse ), the next items to test are the MFS ( MultiFunction Switch ) and the main headlamp switch ( test not look at it ).

The main headlamp test chart


The test chart for the MFS

The vehicle should not have to be running for head lights to burn.If high beams work,then the low beam head lights could be burned out,even though they light up with high beams.The dimmer switch,can be the problem if the head lights only work on high beam.

Pull the head light switch and check it for out put.Do you have high beams?Check the low beam headlight bulbs.If you have high beams,and low beam bulbs are good,replace the dimmer switch.

Somehow the tan wire from the low beams has been cut from the hi/lo switch and is now attached to the brown wire from the headlight switch. Trace the tan wire from the headlights to the hi/lo switch to see what happened.

check your head light switch