1990 Limited, factory abs which I converted to non abs. (Dual diaphragm booster/master cyl) So, when I pull the park brake, no light on the dash. Turn the key to run position, no dash brake light. Crank the engine and the light comes on while cranking, turns off as soon as it starts. So the bulb is working. Checked the park brake switch and it’s functioning as intended (goes to ground with the lever pulled). All fuses check out. All the abs components have been removed, however the wiring is still there, just unplugged. Is there a wire or something in the abs harness that needs to be connected or grounded to make my park brake indicator work properly? I have an explorer 8.8 and every time I get the park brake working right, I drive with it engaged and then it throws off all my adjustments! Very frustrating 😤

 

Check if you are getting +12v to the park brake switch wire. From what I can gather, the ABS removal should not have any effect, it just removes another potential path to ground.

If you've got no power there, check the connector in the diagram for corrosion or a pushed pin.

As the light works on cranking, it shouldn't have anything to do with the brake switch in the engine bay. Let us know how it goes.

 

Thanks for the diagram! Could very well be that connector. I’ve been chasing corroded connections in this Jeep every since I got it! Could have something to do with the 4” of standing water in it for over a year 😋. Just had to clean the rust off the horn button this week to!

 

Mine could have collected a lot of standing water when it was stood for 7 years, luckily for me the floor started to rot in places and let the water back out.

I'm sure to doesn't need saying but check every connector you can and also the fuse board. Corrosion doesn't just stop bits from working but can create high resistance - causing heat.

 

No 12v to the switch.
No 12v to the connector.
Resistance checked the connector and it’s good.
Resistance checked the switch from the connector and it’s good.
There are 2 green wires coming into the harness/power side of the plug. Neither has 12v.
all fuses check good.
Where is this circuit powered by? Fuse? Relay? I’m not the best at reading wiring schematics.

 

The circuit is powered by a feed in the light cluster. As it comes on while cranking, it means there is power to the bulb.

That just took me a while to trace back and properly work out so I'm 99% sure on this, the ABS module does play a part in this. The parking brake switch runs to another brake switch then into the ABS module, a feed then comes back out which heads off to all of the other ground paths and the dash bulb.

Please test this out before jumping wires but you should find pin C9 (ABS module connector) will be grounded with the park brake switch engaged or the low fluid level switch engaged. Pin C5 should be +12V and when you crank it over, should drop to 0V as the light turns on. If this all checks out, by rights, jumping those 2 pins should complete the circuit and give you your dash light back. Let me stress, please test that what I have said matches up and if you have any doubts, don't be jumping wires across.

 

We traced the circuit back to the abs module to, but really didn’t know how to test it. I’ll do the tests and see if your idea works. Thanks for all your help!

 

You are the man! Checked out and works awesome! Thank you so much! Damn, I need to buy you a beer 🍻 or 6!
How the hell did you figure that out? You must have wizardly electrical powers!

 

I'm still learning how to read the wiring diagrams but I can get my head around them. Glad to be of service anyway. Hopefully this can help someone else too.

 

You must be at the top of the learning curve! Good job 👍. Thanks again 🙏