04, 4.7 5 spd man, 4x4.
I asked the same question(s) in a thread with the same heading but it's an old thread so I figured nk-one was looking .....sorry for the repeat.

This spring battery went dead replaced, when I did my abs(orange) brake light(red) came on my speedo altho read correctly when moving jumps between 20 and 40 KMH.

When I bought the truck the guy had her certified for me, he changed the back brakes from drums to disc.

I bought a new abs speed sensor and before putting it in checked the ohm's.
The old 1.5 jumping to 1.7, the new stayed steady at 2.0 so I swallowed and replaced...no difference, lights still on speedo jumping the same.
My OBD2 reader gives me no codes or errors...

I am wondering if the mechanic reflashed the ecm or abs unit? and the speedo sensor is not reading the new config right?

How do I test the brake switch?

Everything was fine till I changed up the battery, BTW when I did I hit the 50 amp circuit breaker (was siliconed so wasnt the first time) and broke it, I also replaced that, for the electrical brake unit for the towing package...unless it burnt my switch I cant see that being related.

Any ideals knowledge greatly appreciated and your patience in restarting the thread as well.

Thanks

 

Could be a bad sensor wheel in the rearend that the sensor reads. It may have missing teeth causing the erratic readings. You will have to pull the cover to check it.

 

..but the sensor is magnetic, so any "shavings or fragments" would have stuck to the sensor? (outside of oil she was clean).
Also, I just came back (tha'ts why the delay) from a extended road trip, started the truck to move her a few feet and she stalled.
I can smell gas and most definitely "popped" the gas line somewhere underneath that tin shield...gas everywhere ....took a moment to look.
This is a 2004, 1500, 4x4 (there are no emblems such as st or slt) that I bought last summer privately, it was certified by this guys mechanic.
I had absolutely no problems before i took her off the road last December.
All this abs and brake light problems did not appeared till I changed the battery.
I'll be crawling underneath her today to fix the gas line, while I was there yesterday, I could not find the wires leading to my front ABS units, I will post pics.
Would it..or is it possible to "flash" this truck into thinking there is no need for abs? Taking out the battery reset everything back to factory?

When looking for why my truck stalled I left the key on, noticed after a minute the speedo went to the zero position while key was on the run position.

Parts are costly here in the north, but I'd rather swallow a few hundred making the truck right, particularly when it comes to brakes.

Thanks for your replies, patience and please bear in mind ...altho a older gentleman (use that term loosely) this is my first dodge in 25 years...and I still think very fondly of my 77 aspen with the slant super six....

 

All is well, she righted herself upon replacement of a gas line...
I ran her without puting the breather on and left intake cold air sensor unplugged to make sure of a "no leak" situation upon putting everything back on engine light came on came up with code P0113 (air intake voltage too high) so I cleared the code, took the positive off the battery and then checked my brake switch and did a visual on the wiring etc.
By the time I restarted the truck, speedo fine, no lights...go figure...wont let her sit this year.
Thanks to all who replied...mods close the thread?