Interior dome light comes on (dim) when brake pedal is applied. 1996 ford ranger.

Please check the link, thanks

https://www.ranger-forums.com/general-technical-electrical-18/dome-light-not-working-148323/

I might be wrong, and occasionally I am, but there are no relays involved with the Brake Light. There is a switch that is activated by pressing the pedal. Some are hydraulic, some are mechanical.

https://www.carid.com/2008-ford-ranger-light-relays-sensors-control-modules/

https://www.google.com/search?q=stop+light+relay+in+my+2008+Ford+Ranger

..

Keith, 1995 ford ranger, looks like interior light fuse is # 27, 10 amp. in interior fuse box panel and module #3 in under hood fuse/relay. Pg. 308 to 315 in the attached manual show fuse locations for all. Check the attached links,instruction and guides, Good luck
"I hope this helped you out, if so let me know by pressing the helpful button. Check out some of my other posts if you need more tips and info."
Ford Ranger 1996 2007 fuse box diagram USA version Auto Genius
Diagram of 1996 ford ranger fusebox which fuse is
Ford Ranger Owner Manual
1995 ford ranger xlt interior light fuse location Google Search

You have a short in the brake system wires. Id start disconnecting everything one at a time until the dimming goes away. Then that component will be your issue. Whether it has failed or the wires going to it are shorted will depend on diagnostics and what it shows.

I’m happy to help further over the phone at https://www.6ya.com/expert/david_c087e4b7d13c0163

So when the engine rpms are faster the lights are brighter and when you brake the rpms are lower and the lights dim and there is a whinning> When it whines, see if it is coming from the alternator. That could be the problem

It can be loose wiring or issue with bulb or the battery is weak or brake light socket getting short somewhere.Car lights getting dim,there are many such common issues noticed.I will share some familiar help links,related to your problem.
Click the link below:---2004 Dodge Ram: High Beam Light is DIM? http://technoanswers.blogspot.in/2012/04/2004-dodge-ram-high-beam-light-is-dim.html
----------Ford Odometer Dims intermittently http://schematicsdiagram.blogspot.in/2012/07/ford-odometer-dims-intermittently.html
---------Turn Signals Don't Work When Brakes Are Applied? http://schematicsdiagram.blogspot.in/2012/04/2005-gmc-envoy-turn-signals-dont-work.html
--------
Brake light Switch Location? http://schematicsdiagram.blogspot.in/2012/04/1996-buick-regal-gran-sport-brake-light.html
----------- No brake lights on Buick? http://schematicsdiagram.blogspot.in/2012/04/no-brake-lights-on-buick.html
----------- Brake lights not working on 1989 BUICK REGAL? http://schematicsdiagram.blogspot.in/2012/04/brake-lights-not-working-on-1989-buick.html

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These will help.
Thanks.

all the lights above the dash do not work ?????? DOME light's ??? No light's come on when you open the door or any door ? Wouldn't think all the door ajar switches bad at one time .
Interior Lamps
The interior lamps consists of two groups, lamps that can not be dimmed and lamps that can be dimmed. This first group consists of lamps that may not be dimmed. This Includes those lamps that may be manually turned on by placing the interior lamp switch to the DOME position, or by opening a door or a compartment:
• Auxiliary dome lamp (SEO, RPO 6C7)
• Dome lamp
• instrument panel (I/P) compartment lamp
• Inside rear view mirror lamps
• I/P courtesy lamps
• Reading lamps
• Rear compartment courtesy lamp
• Sunshade vanity mirror lamps
Battery positive voltage is applied at all times to the DIC/RKE fuse and to the switched side of the BATT RUNDOWN PROTECTION relay in the right I/P junction block. The DIC/RKE fuse supplies battery positive voltage to the coil side of the BATT RUNDOWN PROTECTION relay. When the ignition is turned to the ON position, the body control module (BCM) provides a ground to the Inadvertent relay control circuit. This energizes the BATT RUNDOWN PROTECTION relay and applies battery positive voltage to I/P BRP fuse and to the TRK/ROOF/BRP fuse. Battery positive voltage is applied from the I/P BRP fuse to the I/P courtesy lamps, I/P compartment lamp and to the I/P compartment feed circuit to the BCM. Battery positive voltage is also applied from the TRK/ROOF/BRP fuse to the:

If the BCM receives a door lock or unlock input signal, the BCM will activate the BATT RUNDOWN PROTECTION relay, which provides battery positive voltage to all interior courtesy lamps. When any door is opened, the door jam switch contacts close and the BCM receives a door-open input signal. The BCM then applies a ground to the theater dimming ground control circuit illuminating the courtesy and dome lamps.
After all the doors are closed, the courtesy lamps remain illuminated for approximately 40 seconds. The courtesy lamps will also turn on and remain illuminated for approximately 15 seconds after the ignition key is removed, prior to any door being opened.
When the headlamp switch is placed in the DOME position, the BCM receives a ground signal. The BCM then applies a ground to the theater dimming ground control circuit. This illuminates the dome and roof rail lamps.
The courtesy lamps will normally turn off using the theater dimming feature. The BCM provides a pulse width modulated ground to all courtesy/reading, dome, and inside rear view mirror lamps for the theater dimming feature. The BCM will immediately turn off the courtesy lamps if a door lock command is received with all the doors closed, or if the ignition switch is turned to either the ON or RUN position.
The BCM activates the interior lighting output 15 seconds after receiving the class 2 message "Airbags Deployed" from the sensing and diagnostic module (SDM). The interior lamps remain activated for 25 minutes.

The door ajar switch is part of the lock actuator inside the door !

Usually the brake light switch is located right there under the dash where the brake pedal is located. When you move the brake pedal (apply brakes), the lever that the brake pedal is on will contact a switch, signaling the brake light to come on. Best way to access this switch is by laying on the driver floorboard and looking up: look at the brake pedal, and when you move the brake pedal, watch for it to contact a switch a little higher up the brake pedal arm. Ever notice how when you start your car you can't shift gears until you put your foot on the brake? This same switch is also used in this case. Most of these switches are adjustable so sensitivity can be set properly. If it came loose and the brake pedal does not contact this switch or does not compress the switch's "plunger" sufficiently, the brake light switch will not be operable, hence, no brake lights, or inability to switch gears (when starting up). In other cases, the switch may be defective and will need to be replaced to remedy this situation.

Hope this helps!

your brakelight switch it is way up under the dash it's button makes contact with the brake pedal arm

Are your hazard lights and/or reverse lights working? I can't remember which ties in with your brake lights but one of them do.