Replacing Instrument Panel Light Bulbs in a 1998 Mazda B2500

First of all, welcome to my blog. Explaining auto repairs is really out of character for me, as I am mechanically challenged. I do, however, have determination and a strong sense of curiosity that drives me to find out what I want to know.

This blog is being written because I wasn't able to find an auto repair web site that allowed user participation. So I decided to post my own blog about an annoying problem with my truck that I could no longer ignore.

I'm explaining this from the point of view of a novice. Hopefully this will help someone else fix a problem who was afraid to to try due to lack of experience. As I was once.

Replacing Instrument Panel Light Bulbs in a 1998 Mazda B2500

From a very charitable brother-in-law, I received a 1998 Mazda B2500 (basically the metric version of a Ford Ranger) pickup when my car died last year. Although it was maintained in excellent condition, being a second-hand vehicle with 65,000 miles on it, there were a few items that needed repair. One of these happened to be that most of the bulbs were burned out in the instrument panel, termed the "instrument cluster" in many repair books and blogs. With only part of the panel illuminated, this made me somewhat anxious during night driving, as you can probably imagine. I decided to tackle that job today.

It took me a little while to track down what tools and parts I needed. I list those below so you know it's not rocket science. I could have gone to an auto parts store and asked for standard bulbs, but being a geek, I didn't want to have to repeat this task, a sentiment that was even stronger once I had finished. I opted for LED replacements, which would practically guarantee I'd never have to go through this again.

The instrument cluster in the B2500 is lit by six Sylvania 194 light bulbs. These may also be known as T10 bulbs. The bulb has a wedge base that consists of two exposed wires bent over a flat glass tab and it is simply inserted into a matching socket. Prices varied widely from as little as 10 for $2.00 to the unbelievably high price of $19.99 each. I found a 10-pack of LED replacements on Amazon for $4.99 + $4.99 shipping; these were listed as "Jtech 10x 194 168 2825 T10 5-SMD White High Power LED Car Lights Bulb Super Bright". These turned out to be nearly perfect replacements, being the same 10mm diameter, a 26mm long bulb and base as the original (or about 0.5 inch diameter by a little over 1 inch long).

Here are the tools and parts you'll need to make this repair:

• 6 type 194 bulbs with T10 wedge base
• 7mm socket
• 8mm socket
• Philips head screwdriver
• T20 torx (star-tipped) wrench (helpful, but optional)
• regular pliers to avoid sore fingers
• screwdriver or socket for battery terminals
• flashlight

The steps to access and replace the bulbs are as follows. Warning: be patient and gentle when removing and replacing the shrouds and parts. I managed to break several of the plastic standoffs that align and attach the covers to the panel by using excessive force before I knew how all the pieces aligned.

This was my instrument panel before I started. I've marked the positions of the initial screws you will need to remove for this task.

1. Disconnect the battery terminals. Remove the negative (ground) black cable first, then the positive red one. Mine took a 5/16 inch socket, but my battery and cables have been replaced; use the right sized socket or screwdriver for yours. Wait a couple minutes for the vehicle's electronics to discharge. This is critical if your vehicle is equipped with an airbag, as it could be triggered accidentally by poking around the steering column with metal tools. I hit some wire on my first (uninformed) attempt and accidentally disabled the airbag.

2. Pull out the center radio/vent trim panel from the dashboard by removing the two screws holding it in place, then gently pulling it straight out. You don't need to disconnect anything.

3. Remove the knee bolster, that is the plastic panel beneath the steering column. There are four black screws with 7mm hex heads at the bottom of the panel. Two of the screws hold the hood release bracket to the panel and may take some contortions to remove.

After the screws are removed, pull the cover up and away from the panel to extract the cover and its metal expansion tabs.

Warning: I tried to pull mine straight out and ended up breaking a couple of the plastic standoffs that held the expansion tabs.

4. Remove the steering column shroud. There are three silver philips-head screws in the underside of the shroud. After you remove these screws, gently remove the lower half of the shroud, which you should be able to pull out easily. You will have to manipulate the top half over the emergency flasher button, key release, and out of the instrument panel seal.

5. The instrument panel bezel is held in by three black 7mm hex head screws. Remove these screws and pull the bezel toward you, starting at the top. It should come out fairly easily.

6. Loosen the gold 8mm hex head screws from the metal knee bolster reinforcement panel; you do not need to remove it. The bottom screws only need to be backed out a little. The top screws should be backed out about half an inch, enough to move the top edge in order to expose the screws at the base of the upper cover.

7. Remove the two black 7mm hex head screws from the base of the upper cover. Carefully pry the upper cover, which includes the left vent, straight toward you, to extract the cover with its metal expansion tabs.

The cover also includes the headlight control switch. You do not need to disconnect the wires from the switch; just swing the entire panel out of the way while you continue working.

8. Now the instrument cluster is exposed. It is attached with four black 7mm hex head screws, one at each corner. Remove these screws.

9. Now that the instrument cluster is free, there should be enough slack in the wires attached to the back to allow you to replace the bulbs without disconnecting anything else. Note that there are six bulbs, each one held in place by a black twist-mount carrier. The other white twist mounts, solder pads, wires, etc. on the circuit board are not important for this task, so don't cause any damage by trying to remove anything else.

10. Remove each bulb carrier by twisting it one quarter turn counter-clockwise, then lift straight out until the bulb is clear of the circuit board. If the carrier is stuck and you are hurting your fingers, gently use pliers to turn it.

The carrier is a press fit socket with two contacts on either side of the bulb that connect to pads on the circuit board. Pull the bulb straight out of the carrier and replace it with your new bulb.

11. Reinstall the bulb by inserting the bulb and carrier back into the cutout in the circuit board until the carrier rests against the board. Twist it gently one quarter turn clockwise. After all bulbs are in place, reconnect the battery temporarily and engage the parking lights to check that all bulbs are working before reassembly.

12. Unlike the original incandescent bulbs, LED bulbs have a polarity, that is, a positive and negative side. If the LED bulb does not light, remove the carrier and bulb and turn it 180° from the way it was inserted. Reinsert the bulb and carrier and give it a one quarter turn clockwise to lock it back into place. The bulb should now light. Make sure all bulbs are working before you put everything back together.

13. Disconnect the battery again while you reassemble everything in reverse order, then reconnect it positive side first, then ground. Congratulations, you should now have a completely illuminated instrument panel again!

Another tip: these LED replacements for the type 194 bulbs make great dome lights, too!