High beams stuck "on", switch question..

[EXJAY]

Had this issue since I got my 88 K5 and had a little time yesterday to look into it. When I turn on my headlights all 4 lamps come on "high beams"and the high/low beam switch dosent seem to have that "click" feel/sound to it, also I get no high beam indicator on the dash (which maybe part of my no dash light issue). I removed the access panel under the column to look at the high/low beam switch. When I pull back on the wiper stalk the rod pushes down the switch all the way and moves freely. Ive tried to operate it also by hand but same result. I removed the 3 prong plug and checked the switch for operation (continuity test) and no matter which leads im on and if the wiper stalk is pulled back or not I cant get anything to ohm or short out ot eachother or ground. I also have with the lights on 12v at two of the 3 wires (tan, yellow, lt green) that plug into the high/low switch. When I remove the plug all headlights go out. Im not sure if this is how its suppost to work or not but still tring to figure out the electrical flow. Sweems like the high/low switch is stuck in the high beam position..Thoughts/ideas, help?? This is what Im going on..

http://brochures.slosh.com/index.shtml?1988 (top left corner)

 

[readymix]

Is there play in your steering column?

 

[EXJAY]

Not that I can tell. A few more questions pls (still new to these models)..

Just to confirm, when low beam lights are on all 4 should be lit up and when going to high beam the top lights go brighter correct? With the lights turned off and you pull back the wiper stalk high beams should come on right? Also does the dash pull light knob switch have any bearing on the high/low operation?

 

[readymix]

1. Not sure. I only ever had the two bulb grill on my trucks.
2. That is the way i remember it working.
3. None at all, except for turning them on. High / low is controlled by the wiper stalk.

 

[EXJAY]

1. Not sure. I only ever had the two bulb grill on my trucks.
2. That is the way i remember it working.
3. None at all, except for turning them on. High / low is controlled by the wiper stalk.

Thanks. The more I look into it sounds like the switch is stuck or broken in the high beam selection. Going to pull the switch here in a few to get a better look at it. Shouldnt it close/open the terminals durring operation much like a relay would? When I tested it they would all stay "open".

 

[readymix]

I'm not real familiar with that switch but i would assume it is a DT with the highs being NO and the lows having a set of NC contacts.

 

[EXJAY]

I removed the 3 prong plug and checked the switch for operation (continuity test) and no matter which leads im on and if the wiper stalk is pulled back or not I cant get anything to ohm or short out ot eachother or ground.
http://brochures.slosh.com/index.shtml?1988 (top left corner)

Correction on the above statement. On the switch connection that correspons with the yellow and lt green wires on the harness are always closed together and tan wire always open.

 

[kennyw]

Your low beams should only be the top two lights. High beams switches the top two to the brighter setting and turns on the bottom two.

 

[EXJAY]

OK just as an update the switch was infact bad and stuck in the high beam setting. I was able to remove the switch and took it apart to see (just for S &G's) what caused it to fail. Wasnt able to fix it but Napa had one in stock and we're back in business. Thanks!

 

[89k5350]

on my 87 ive got the 4 headlights and low beam is just the top 2 and high beam is all 4

 

[EXJAY]

^ Yep. How mine is now since the switch was replaced. I think my high beam dash light is burnt out though as it still will not come on. Is it reachable to remove going from under the dash?

 

[Zane M]

^ Yep. How mine is now since the switch was replaced. I think my high beam dash light is burnt out though as it still will not come on. Is it reachable to remove going from under the dash?

If you are a contortionist with very slender/flexible arms, and are good at doing things by feel, then yes.
Most likely you are going to have to pull the guage cluster. If you do that, may as well replace all the bulbs while you have it out, even if they are good now.