Changed lights to LEDs. ABS system down.

[JMF661]

Hello everyone!

1994 4x4 ranger.

Just like the title. Installed LEDs for the turn signals, brake lights, and backup lights. Now the ABS dash dummy light is on, tested the truck, ABS is definitely offline. Maybe there is a way to remedy this and keep the LEDs, probably just going to buy some conventional bulbs and make the switch back, anyway, I thought this was a fun fact.

 

[sgtsandman]

I'm at a loss on how the LEDs would affect the ABS system. I'll be interested to see how this works out.

 

[JMF661]

I am as well. They could be unrelated, but it is quite the coincidence that I changed the bulbs and immediately after the abs light came on. Going to have to experiment with it next weekend.

 

[Curious Hound]

How's the level in your brake fluid reservoir?

 

[RobbieD]

The RABS system has to "see" ground from the unlit taillight brake bulbs. Same with the cruise control. Regular LED bulbs don't have enough resistance to satisfy these control units. You'll need to get "loaded" LED bulbs that include a resistor for this purpose, or go back to incandescent bulbs like the originals.

 

[JMF661]

How's the level in your brake fluid reservoir?

I don’t know what is real anymore.

 

[JMF661]

The RABS system has to "see" ground from the unlit taillight brake bulbs. Same with the cruise control. Regular LED bulbs don't have enough resistance to satisfy these control units. You'll need to get "loaded" LED bulbs that include a resistor for this purpose, or go back to incandescent bulbs like the originals.

I figured it had something to do with something like this.

 

[RobbieD]

I don’t know what is real anymore.

Nothing to worry about. Reality is like way overrated, anyway.

 

[Blmpkn]

The RABS system has to "see" ground from the unlit taillight brake bulbs. Same with the cruise control. Regular LED bulbs don't have enough resistance to satisfy these control units. You'll need to get "loaded" LED bulbs that include a resistor for this purpose, or go back to incandescent bulbs like the originals.

Is this the same with 4 wheel abs?

 

[Dirtman]

Is this the same with 4 wheel abs?

No

 

[cbxer55]

I am as well. They could be unrelated, but it is quite the coincidence that I changed the bulbs and immediately after the abs light came on. Going to have to experiment with it next weekend.

I changed the brake light switch and the ABS came on the first time I drove it. Never saw it prior to that. Anyway, my reading on the subject says the brakes will work just fine without the ABS, so I am simply going to leave mine the F alone. Sick to death of chasing little problems with this truck. Had it 20 years, and it's always something. I put a piece of black tape on the dash over that area. Can't see it no mo.

 

[JMF661]

How's the level in your brake fluid reservoir?

But, for real the level is good, I have recently flushed and serviced the entire brake system. Pretty sure I am experiencing an electrical issue related to the LED conversion. I’m going to swing by the parts store tomorrow and pick up some new conventional bulbs. Took the truck out earlier, the abs system is definitely out, but man, those mud terrains howl so beautifully on the pavement when locked up. However the sideways motion of the rear of the truck is less than desirable.

 

[racsan]

my abs light has been on the whole time Ive had my 94. thought it was the rear axle sensor but still on after I swapped axles. Brakes work ok so I put black tape over the light and don’t worry about it now.

 

[noticz]

I can 100% verify that changing the RABS light to an LED will permanently keep it on. The RABS computer sees that the line doesn't have the correct resistance and lights it up thinking something is wrong with the line (while not throwing any codes). Changing just that light back to incandescent bulb will fix the problem guaranteed. Everything on the cluster from 1983-1988 that I know of can can be changed to LED bulbs except the RABS light. One of those LED resistor lines could help with this but cost of that compared to just switching back to the regular bulb is a no brainer.