94 f150 running rough, battery light on dim - Ford F150 Forum

vlasveld · 08-16-2010, 11:02 PM

Hey guys I have a 94 f150 4x4 4.9l

Here is what is happening:

1. When i go to start it it really chugs and farts unless i lay my foot on the gas to get it going.
2. While im driving i can see the battery light is on like its dieing but its very dim
3. its running really rough... if i have my foot on the gas LIGHTLY just as im cruising down the road it bucks and chugs.

Not sure what this could be? The fuel filter and air filter are near new.

Any help would be greatly appreciated as this is my daily driver and only vehicle

THANKS!

94Bronc · 08-17-2010, 01:37 AM

check battery and alternator, then codes, see sticky at top of section

vlasveld · 09-08-2010, 08:36 PM

Hey again... i cleaned up the corrosion around the battery and made sure the grounds were all clean and connect and no luck.

I ran the code reader 3 times .. first time came back with 122 which means throttle position sensor below min voltage.

ran 2 more times nothing came back.

Not sure what else it would be? If it was the alternator how would i tell?

dirtcrew51m · 09-08-2010, 09:07 PM

Check alternator, start truck, pull positive cable off, if truck dies, its alt, if not it is something else. You could also check alt by using multimeter, battery should be reading 14.5 or so volts.

vlasveld · 09-08-2010, 10:24 PM

Quote:

Originally Posted by dirtcrew51m

Check alternator, start truck, pull positive cable off, if truck dies, its alt, if not it is something else. You could also check alt by using multimeter, battery should be reading 14.5 or so volts.

Ok I just went and picked up a multimeter really quick to do the test.

I started the truck and tested it.. it came out at 14.1 volts while running

Then i Turned it off and it read 12.6 volts while not running (not sure if i was supposed to wait awhile before testing it while off since it was just running)

Not sure where to go next?

dirtcrew51m · 09-08-2010, 10:30 PM

Thats normal, as long as it says 14v running charging is ok, how old is your cap\rotor\wires\plugs?

vlasveld · 09-08-2010, 10:43 PM

Quote:

Originally Posted by dirtcrew51m

Thats normal, as long as it says 14v running charging is ok, how old is your cap\rotor\wires\plugs?

I bet 1-2 years

can they have anything to do with why the battery light would be showing on?

dirtcrew51m · 09-08-2010, 10:56 PM

no, you most likely have a drain of some sort.

vlasveld · 09-08-2010, 10:59 PM

Quote:

Originally Posted by dirtcrew51m

no, you most likely have a drain of some sort.

What do you mean by a drain? LIke a short or something that is sucking the power out of the electrical system?
If it was a drain wouldn't the battery be reading lower with the vehicle turned off?

aliens8mycow · 09-08-2010, 11:17 PM

Was there a lot of corrosion at the battery terminals? Could be running through the battery leads - if you slice the insulation on them an inch or so back from the terminal, I'll bet one or both is full of corrosion. That builds up a ton of resistance, and will cause all sorts of problems. A new set is fairly cheap and easy to replace.