Is this normal? I have only had this truck a short amount of time but the 4x4 light next to the switch sometimes stays on and sometimes goes off. I知 very worried because the 4x4 low light illuminated tonight while I was driving. I知 not sure if it even works. How can I test it?

 

Welcome to the forum

What YEAR ranger?

What engine size and manual or automatic trans?

No its not normal, could be shift motor or control module problem, depends on the year

 

 

You will have this control system: https://therangerstation.com/tech_li...ol_module.html
I would test the 4WD system to see if it works


The switch on the dash doesn't control the lights, the module does

Both lights(4high/4low) get 12volts with key on, but are Grounded by the module to turn them on, so could be these wires are shorted to ground somewhere, insulation has worn away so it gets a partial ground now and then.

At the module you will see lots of wires, lol
Brown/white stripe wire should be the ground for 4low
Grey wire the ground for 4high
Not sure on the 1989 wiring colors


The way the system works.
On the transfer case is an electric motor that has a reduction gear that turns the transfer cases shift rod to its 3 positions, 2WD, 4High and 4Low
In the shift motors case is a contact wheel that turns with the shift rod, these contacts "tell" the control module the position of the shift rod, so module "knows" position of shift rod with Key on or when it moves the shift rod it can stop motor when "contacts" show correct position, 2WD, 4high or 4low
When shift rod is in the correct position, module THEN grounds the 4high or 4low light, or ungrounds both for 2WD, so when you select 4high there should be a delay until 4high light comes on, not much but a delay, longer delay for 4low because shift motor has to move shift rod farther

This thread shows pictures of shift motors various parts: https://www.explorerforum.com/forums...-motor.123542/

The Control Module will Flash 4WD lights if shift motor is not working or if contacts are incorrect when you try to use 4WD

The most common issue with this system was lack of use, and the electric shift motors brush and rotor losing contact, this can be avoided by shifting to 4low once a month, don't have to drive it, just shifting it from 2WD to 4high and then 4low and then back to 2WD sitting in the driveway, keeps the motor clean and usable for when you do need 4WD

So grab a volt/ohm meter and find your control module and start testing

You can shift into 4high while driving(under 50MPH), system has an electric clutch in the transfer case for that, and you can shift back to 2WD from 4high while driving
If you have automatic front hubs they will Lock when you shift into 4high while driving, but won't unlock when you go back to 2WD, not a big deal, when you stop and back up in 2WD the hubs should then unlock
To shift into 4low the module requires speed to be 0MPH, foot on the brake, and clutch pedal down all the way, with an automatic shifter must be in Neutral

 

 

I've had a similar problem with my 2010 Ford Ranger PK where the 4x4 light would appear and stay on. The light would always turn off after I turned the car off except for the last time when the light remained on for weeks. I tried all the problem-solving tricks in the book from putting the car into neutral, waiting 20 seconds, driving forwards and backwards, etc. Nothing worked and the 4x4 light remained on. It became a problem when I found out that as a result of the 4x4 light remaining on that my odometer would only registered 1/3 of the kilometres I was driving, and my speedo would only register a maximum of 40km/h. My mechanic didn't know what was causing the problem, he even lifted my truck onto his hoist and confirmed that even though the 4x4 light was on that the truck was NOT in 4wd mode (only 2 wheels were rotating). I took the truck to another mechanic who told me the issue was 1 of 2 things, either the switch was faulty, and the cables needed replacing, or the transfer case needed looking at/replacing. I took the truck back to my mechanic to have a look at the transfer case 4x4 shift motor actuator. He played around with it, cleaned, and looked at the cables. He drove the truck back to me and the 4x4 light was OFF :):), although this didn't last long and a few days later the light appeared again. My mechanic then sent through a quote for $2000 to fix the problem. I was not going to pay this kind of money, so I jumped under my truck, took a picture of the existing transfer case 4x4 shift motor actuator and the part number, I went online and purchased the same part for $94 and got my mechanic to replace it (it took him 30mins to change over the part). It痴 now been 6 months and the 4wd light has not appeared on my dash again, I can transfer from 2wd, 4wd and 4wd low without any trouble and the light adjusts the way it should and turns off. Problem solved; my issue was that I needed the replace the transfer case 4x4 shift motor actuator. A $2000 quote and I fixed the problem with $94. Hope this helps you.