Abs light and brake light started coming on and staying on. I also have noticed that the speedometer while in idle is jumping all over the place. I checked the pads and they are good. I recently had a trailer brake installed. Thinking there may be a short I redid all the terminations. No good either.Any ideas. I would hate to have to buy another abs module.

First thought is that if you have a judder from the brakes you may have a warped front disc. The ABS system sensor may be picking this judder up and converting it to a fault.
A warped disc would spin and catch then spin and catch again rather like the rapid on/off braking that ABS does. This 'could' be the judder you feel and should be especially noticeable when braking and barely noticeable when driving with the brakes completely off.

look under the truck at the ****** and check the wiring to the sensors if good may be a bad sensor,also check the wiring and connections to the abs wheel sensors [ located from frame to the hub behind the rotors ] the abs also acts as speed sensor if problem was with an abs sensor at the[ hub] wheel usually set the brake system to normal power brakes [if u hit brakes hard will lock up or skid wheels] with the abs light coming on if the speed sensor at ****** malfunction can and usually causes shift problems

For speedometer problem click the link below :---

How to trouble shoot speedometer?

http://schematicsdiagram.blogspot.com/2011/06/speedometer-not-working.html

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speedometer not working?

http://technoanswers.blogspot.com/2012/01/1996-fiat-bravo-speedometer-not-working.html

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Speedometer runs backward?

http://technoanswers.blogspot.com/2012/01/speedometer-runs-backward.html

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Warning lights on and speedometer died?

http://howtobyme.blogspot.com/2011/08/warning-lights-on-and-speedometer-died.html

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ABS & Brake lights warning indicator steady on dash and speedometer not working?

http://howtobyme.blogspot.com/2011/11/abs-brake-lights-warning-indicator.html

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Odometer works properly but speedometer works intermittently?

http://technoanswers.blogspot.com/2012/01/odometer-works-properly-but-speedometer.html

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speedometer is jumping?

http://schematicsdiagram.blogspot.com/2012/01/isuzu-rodeo-speedometer-is-jumping.html

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This will help.

Thanks.

For speedometer problem click the link below :---

How to trouble shoot speedometer?
http://schematicsdiagram.blogspot.com/2011/06/speedometer-not-working.html
-----------speedometer not working? http://technoanswers.blogspot.com/2012/01/1996-fiat-bravo-speedometer-not-working.html
---------Speedometer runs backward?

http://technoanswers.blogspot.com/2012/01/speedometer-runs-backward.html

----------
Warning lights on and speedometer died? http://howtobyme.blogspot.com/2011/08/warning-lights-on-and-speedometer-died.html
---------ABS & Brake lights warning indicator steady on dash and speedometer not working? http://howtobyme.blogspot.com/2011/11/abs-brake-lights-warning-indicator.html
--------Odometer works properly but speedometer works intermittently? http://technoanswers.blogspot.com/2012/01/odometer-works-properly-but-speedometer.html
----------speedometer is jumping? http://schematicsdiagram.blogspot.com/2012/01/isuzu-rodeo-speedometer-is-jumping.html
-----------This will help.Thanks.

not a good idea to do a voltage test on a computer component, it can result in damage to the ECM.
if only the speedometer is not working and the other gauges do work, the first place to start is the speed sensor, it is the most common issues with inoperative speedometers.

check for codes with scanner it most likely is the abs sensor on the rear differential housing that is bad easy fix

my radio turn off then my brake light start to blink and chime ringing also my a/c light blinks i have 110,000 miles 2006 ram 1500 2wd 1 ton what can this be?

check fuses and relay for ur abs- possible bad relay or abs unit -have vehicle scanned some auto stores such as auto zone /advanced auto do scan for free ur trouble code(s)will give u a place to start

I had the same problem with ABS light and speedometer, I was told that it is the transmission control module. It has not yet stopped shifting but I have had times where it just wont stay running. It will start and then stall. Hope this helps.

it sounds like it is the speedometer cable that goes from the speedometer gauge to the transmission is wearing out.unless you have done one of these before then i would suggest having someone do it for you.