Hello,

My 2006 Ranger (2.3L) battery light has been on for the past week. I was driving and all electrical systems in the truck died going highway speeds. I exited, and while driving in a parking lot the engine was very rough and revved constantly. When I came to a stop in a parking spot the engine died.

I jumped it and it started right back up and no problems driving it home. Tested battery and it was fine. Replaced alternator today, and started right up, but now has an extremely rough idle, causing it to die.

I triple checked my serpentine

this is in the front passenger side right behind the headlight, it is the top line going into this circular housing.

belt, and then found this line not connected to anything. What is it? and how do I fix it? Is this the cause of my rough idle?

Thanks so much.

 

Could be vacuum reservoir

Has 1 black vacuum hose from the engine/intake
And other black hose runs to the firewall passenger side by heater fan box

This vacuum system runs the VENTS in the cab, i.e. air flow direction, defrost, panel, floor, this is probably not working
Defrost is the default vent, no vacuum = defrost only

These hard plastic vacuum lines can be repaired with proper size rubber vacuum hose, just slide on rubber hose over hard line, should fit snug, to connect the broken lines, its Vacuum so no clamps are needed, it pulls together it doesn't try to push apart

Yes, a vacuum leak can cause rough idle


Battery Light on with engine running means alternator is not working , which means spark and fuel pump is now running off the battery, also radio and any lights that are on
So don't DRIVE IT until alternator has been tested or replaced

And battery is probably NOT good any more

Get a volt meter and test battery after truck has been sitting over night or at least 4 hours
key/engine off
12.8volts is a new battery
12.5v is a 3 year old battery
12.3v is a 5/6 year old battery<<< shop for battery sale

12.2volt or less is a done battery, replace now

Start engine
Battery should now read 14.5volts, under 15volts, alternator is working
Let it idle for 5 minutes, do not turn engine off
Retest, battery should show under 14volt now, above 13.5v, voltage regulator in the alternator is working
All is well if these simple tests come out OK