Please help asap!

[aaron_ariens]

My 01 Ranger, sometimes when I'm driving, the Batt light comes on, then the volts go all the way up, past the H, and my ABS light comes on when this happens, then....my auto tranny shifts SUPER hard.

It's doing this, so I had to turn around and go home, in 2nd, going like 30. =[[[


whats wrongg?!

 

[Earl43P]

Get the alternator tested.

Most parts stores do it for free.

 

[oachs83]

Possible bad ground to the battery. Your rear wheel speed sensor is not comunicating. Your computer takes your speed from the speed sensor and that also tells it how to shift. When the senor goes out your computer does not know where the speed is exactly at. The first thing you should do is try and retrieve the ABS code.

You can sometimes just clean the sensor, it is near the top of the rear differential. It's just held on by one 3/8 or 10mm bolt and a two prong plug. Take it out and wipe it clean with a clean rag. Reinsert and see what happens.

 

[aaron_ariens]

Okay cool, I'll try that.

No codes came up, I just had it scanned. ABS light is off now, and it's only surging randomly now.

 

[SMTGREG]

Test the battery voltage when the problem is happening ,it sounds like high voltage causing the ABS concern. Above 16 volts. Probably the voltage regulator within the alternator.

 

[aaron_ariens]

Yeah, or things are fine, then if I go and speed up real fast, things will start up again.

 

[Earl43P]

Sounds like a typical alternator failure due to worn brushes.

When you increase engine rpm, the brushes "float" over the commutator because they are so worn the brushes' springs can no longer keep the contact pressure.

Since your ABS uses frequency pulses to determine wheel speeds, the varying voltage makes the ABS think there is a radical change in wheel speeds, resulting in an ABS light.

Replace the alternator. At LEAST get it tested and make sure they rev the engine during the test. It will help if you can say "it happens at XXXX rpm" and test it above and below that speed.

Obviously, the transmission uses the same varying voltage and frequency pulses (vehicle speed) to determine shifts. Fixing your Battery light problem should fix the hard shifts too.

I can't rule out a battery cable problem, grounds, etc, but your symptoms point to a bad alternator. It'll strand you with a dead battery soon.

 

[betomonroy]

You rock Earl.

 

[evanesce69]

I agree with earl, if the battery guage shows high, one of two conditions exist: the alternator is faulty or the battery has shorted cells.

critical electrical systems usually have control over the frequency of the supply voltage. if the alternator is acting goofy, it can effect the performance on the dependent subsystems.





Rob