Help with electrical problem

[az08t]

About a month ago, the abs and traction control lights came on while driving and the speedometer and tachometer needles began jumping. Resolved with restarting vehicle, battery checked out bad and replaced it with no issues.

A few days ago it happened again, battery checked out fine. Alternator test shows failed voltage regulator. I brought into Toyota today but no lights are on and needle isn’t jumping around so they’re thinking they won’t find anything. Any ideas? Thanks!

videos of gauges

 

[lewdog998]

Always check, remove, clean and reattach your ground wire. A finicky ground can cause all kinds of weird gremlins. This is an easy thing to check and eliminate from the equation.

 

[rwrobs777]

About a month ago, the abs and traction control lights came on while driving and the speedometer and tachometer needles began jumping. Resolved with restarting vehicle, battery checked out bad and replaced it with no issues.

A few days ago it happened again, battery checked out fine. Alternator test shows failed voltage regulator. I brought into Toyota today but no lights are on and needle isn’t jumping around so they’re thinking they won’t find anything. Any ideas? Thanks!

videos of gauges

You may have excessive alternator ripple (bad alternator diode) causing these kinds of issues...they will affect any sensor that uses AC voltage...wheel speed sensors and speedo/Tach...video below !!


Bad Alternator Diode causing transmission/speedometer problems - YouTube