Help with new to me Silverado

[kyleag89]

Hello I just bought a 2003 Silverado 1500 Z71 4x4 with a host of issues.  The 2 main issues I'm dealing with now are the ABS pulsating at 5mph and under stopping, and the lights flickering while idling.  These are 2 common problems as Ive gathered.  I just finished installing new front and rear rotors and pads.  I cleaned the front 2 wheel speed sensors one of them looked brand new, the other one had cut wires and wasn't hooked up at all.  By connecting it I got the ABS light to go out and now ABS works but pulsates.  I was going to replace the old front sensor and the VSS in the transfer case.  When I look at the trans case there are 2 screw in sensors on either side of the tail shaft. I see the screw in type on rockauto.com but are they both identical?  Should I order 2 and replace both of them?

 

Also what should I check first to figure out the flickering lights?  I can see the voltmeter gauge actually fluctuate with the lights dimming. 

 

Thanks

 

[CamGTP]

A new ABS sensor is a good start but the bearing could still be the issues if it's bad internally where it picks up the wheel speed.

 

The 2003-2007 trucks have big problems with the clusters too, watch out that. They start freaking out, no lights, certain gauges just stop working or they start doing loops or get stuck at spots and get a new starting point. Like the speedo with stick at 20mph and then 20mph is the new zero, the needle does a full speed and break off type thing lol.

 

The flickering lights could be a dying alternator or wiring issues. I would remove all battery cables and all the grounds to the body and engine, clean everything and give the cables a new rough/clean surface with the sand paper/emery cloth or scrub pad. The main cables are pretty obvious to find, then look for the ground cable on the drivers side cylinder head to the body and I think there is a ground cable on the front cross member to the block somewhere.

[kyleag89]

Thanks for the reply,  I know all about the cluster because my odometer reads 8 miles.. lol  So far all the gauges have been working, the only issue has been lights sometimes dimming then getting bright again(different from other flicker) and the odometer not counting properly. 

 

As far as grounds go I have already started cleaning them.  I got the engine to body, the battery to chassis under the radiator, and the terminals to batt and alternator.  I haven't touched the 2 grounds under the drivers side seat area to the frame.  The bolt head is rusty and I will most likely need to create a new bolt location for those grounds.  I heard about a TSB that adds another wire from an empty spot on the alternator terminal to the pos+ out terminal to the battery.  I have no idea what or why but I might try that if I can find an insert that goes into the plug. 

[kyleag89]

I haven't had the chance to work on my truck yet, been busy with work.  I have ordered new front ABS sensors and will try those first.  I have over 4k in this truck already and have a ways to go.  She's starting to look really good though!