Why do the dash instrument lights not work but dash hazard and dash blinker lights work? Also the guages work as they should. (1 Viewer)

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this might be a stupid question...I took the knob off but how do I remove the circular coil with a brass wiper? thanks again
I wouldn't open that rheostat. I have read that those heavy tabs are very fragile as Charlie suggested and you run the risk of snapping them. I did the best I could by cleaning from the rear opening with vinegar and a swab, rotating the wiper frequently as I cleaned. Worked for me.

The contacts, on the other hand (in the vented box), can only be cleaned properly by opening that box, again, being very careful with the tabs and watching where everything goes. Not only were the contacts tarnished, but dried grease and dust added to the problem.

Just my opinion, but I avoid using steel wool for cleaning inside switches. A strand left behind can cause shorts if you're not careful.
 
A sliver of one of those nail file boards can reach in places. bend them back and forth a few times can make them more flexible There are some plastic strips with mild abrasive that are like 1/4 wide and bendy. Spray can of contact cleaner that takes a pee tune can wash out a lot of trash. +1 for turn it back and forth to polish the contacts causes a lot less wear and doesn't introduce grit that needs to be washed out..
 
I wouldn't open that rheostat. I have read that those heavy tabs are very fragile as Charlie suggested and you run the risk of snapping them. I did the best I could by cleaning from the rear opening with vinegar and a swab, rotating the wiper frequently as I cleaned. Worked for me.

The contacts, on the other hand (in the vented box), can only be cleaned properly by opening that box, again, being very careful with the tabs and watching where everything goes. Not only were the contacts tarnished, but dried grease and dust added to the problem.

Just my opinion, but I avoid using steel wool for cleaning inside switches. A strand left behind can cause shorts if you're not careful.
How do you remove it, or did you leave in place and clean it from up under the dash panel? thanks
 
How do you remove it, or did you leave in place and clean it from up under the dash panel? thanks
Pretty easy to remove headlight switch for cleaning purposes.

- Disconnect battery
- Remove the knob. Mine unscrewed after Ioosened the tiny philips set screw at 6 o'clock.
- unscrew the round, aluminum nut from the knob shaft (pliers works)
- pull the switch free from the dash
- Disconnect the harness connector from rear of the switch as well as the bulb housing.

A word of caution. You've already been advised not to bend those heavy tabs holding the rheostat for fear of breaking them. One more caution. When opening and cleaning the switch "box", be very careful not to break that central shaft. It carries the illumination from the bulb (in rear), to the face of the knob.

Good luck!
 
Pretty easy to remove headlight switch for cleaning purposes.

- Disconnect battery
- Remove the knob. Mine unscrewed after Ioosened the tiny philips set screw at 6 o'clock.
- unscrew the round, aluminum nut from the knob shaft (pliers works)
- pull the switch free from the dash
- Disconnect the harness connector from rear of the switch as well as the bulb housing.

A word of caution. You've already been advised not to bend those heavy tabs holding the rheostat for fear of breaking them. One more caution. When opening and cleaning the switch "box", be very careful not to break that central shaft. It carries the illumination from the bulb (in rear), to the face of the knob.

Good luck!
Thank you @CruiserInProgress!! You and many more have been beyond helpful. I appreciate you all! I was worried about the round aluminum nut and didnt want to start prying at it without being sure. Thanks, Michael
 
Thank you @CruiserInProgress!! You and many more have been beyond helpful. I appreciate you all! I was worried about the round aluminum nut and didnt want to start prying at it without being sure. Thanks, Michael
You're welcome.

Ha! Yeah, the "use a bigger hammer" or "use a bigger prybar" approach rarely ends well. Lots of great info here on IH8MUD. Enjoy your journey.
 
Pretty easy to remove headlight switch for cleaning purposes.

- Disconnect battery
- Remove the knob. Mine unscrewed after Ioosened the tiny philips set screw at 6 o'clock.
- unscrew the round, aluminum nut from the knob shaft (pliers works)
- pull the switch free from the dash
- Disconnect the harness connector from rear of the switch as well as the bulb housing.

A word of caution. You've already been advised not to bend those heavy tabs holding the rheostat for fear of breaking them. One more caution. When opening and cleaning the switch "box", be very careful not to break that central shaft. It carries the illumination from the bulb (in rear), to the face of the knob.

Good luck!
Another stupid question....Do I use a basic/ordinary combination pliers on the round aluminum knob? It twists off like a standard nut? I cant seem to get it to budge. Banged on it with pliers and a hammer to try to loosen it up but it didnt work.
 
Another stupid question....Do I use a basic/ordinary combination pliers on the round aluminum knob? It twists off like a standard nut? I cant seem to get it to budge. Banged on it with pliers and a hammer to try to loosen it up but it didnt work.
Yep, use pin spanners/snap ring pliers, or thin needle nose to fit in the holes and righty tighty-lefty loosey. It may need a little persuasion from the backside where you will have more leverage twisting the switch body.
 
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Put some Kroil on it. Try to get some on the back side where the threads are. Needle oiler - small soft plastic bottle (like a Vizine bottle) with spaghetti tubing attached into the nose hole.
I haven't looked lately but I think its a pin spanner tool (2 holed for the pins). A lot of times the bezel gets bonded to the paint due to crud. Try to rotate the whole switch from the back just a little to help break the bond.

Find good pictures of the replacement switch and look carefully to see the attachment method.
 
You can try snap ring pliers. Worst case pliers.
 
I’m having the same issues on my 74 but not sure if all the gauges work because I haven’t started it in awhile. However the turn signals/ hazards and him beam indicator works if I remember correctly but the dash lights and dash pad lights don’t.
Does the vehicle need to be running for them to work?
 
I’m having the same issues on my 74 but not sure if all the gauges work because I haven’t started it in awhile. However the turn signals/ hazards and him beam indicator works if I remember correctly but the dash lights and dash pad lights don’t.
Does the vehicle need to be running for them to work?

No. I've had great success by twisting the knob back and forth a bunch of times.
 
Pull the headlight switch and if yours is like mine, you'll see it behind the knob, a circular coil with a brass wiper.

Not all FJ40 headlight switches have this capability.

Mine looks like this

View attachment 3849045

View attachment 3849046
Hi CruiserInProgress, is this ok just to pull out the attached wires? (see pic, circled in red)
And are these the vents to clean? (see pic, with yellow arrow)
Also do I just clean it from the outside or do I open it?
Thanks again,
Michael

Screenshot_20250227_232636.jpg


Screenshot_20250227_232611.jpg
 
Hi CruiserInProgress, is this ok just to pull out the attached wires? (see pic, circled in red)
And are these the vents to clean? (see pic, with yellow arrow)
Also do I just clean it from the outside or do I open it?
Thanks again,
Michael

View attachment 3853118

View attachment 3853119
The harness connector pulls out fairly easily. The light socket, I can't remember if it just pulls out or twists 1/4 turn to come out. Be gentle.

About the internal switch contacts, it depends on how confident you are in your skills, whether you open that vented box or not, by slightly straightening the 4 tabs securing it.

If you're not that handy, you might first try just spraying some cleaner through the vents, working the switch, draining and repeating the process until you get it to work.
 
The harness connector pulls out fairly easily. The light socket, I can't remember if it just pulls out or twists 1/4 turn to come out. Be gentle.

About the internal switch contacts, it depends on how confident you are in your skills, whether you open that vented box or not, by slightly straightening the 4 tabs securing it.

If you're not that handy, you might first try just spraying some cleaner through the vents, working the switch, draining and repeating the process until you get it to work.

The harness connector pulls out fairly easily. The light socket, I can't remember if it just pulls out or twists 1/4 turn to come out. Be gentle.

About the internal switch contacts, it depends on how confident you are in your skills, whether you open that vented box or not, by slightly straightening the 4 tabs securing it.

If you're not that handy, you might first try just spraying some cleaner through the vents, working the switch, draining and repeating the process until you get it to work.

The harness connector pulls out fairly easily. The light socket, I can't remember if it just pulls out or twists 1/4 turn to come out. Be gentle.

About the internal switch contacts, it depends on how confident you are in your skills, whether you open that vented box or not, by slightly straightening the 4 tabs securing it.

If you're not that handy, you might first try just spraying some cleaner through the vents, working the switch, draining and repeating the process until you get it to work.
Will this cleaner be safe to spray into the vents or is white distilled vinegar a better way to go? Thanks, Michael

IMG_1381.jpeg
 
Will this cleaner be safe to spray into the vents or is white distilled vinegar a better way to go? Thanks, Michael

View attachment 3853233
I haven't used that cleaner, but if you're trying to get some cleaning action through the vents, pressure from the spray may help things along.

Or alternatively, immersing the switch assembly in vinegar while working the mechanism might work too.

I haven't tried either, but might be an easier way to go if you're uncomfortable opening up the switch mechanism to take it apart and clean it.

Maybe someone else can chime in?
 
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