Possible Bad Alternator?

Question

1984 Ford 150 Pickup - New Battery- Started with new battery but once it reaches a certain rpm either idling or moving it cuts out and stalls. Tried to restart but all this did was run the battery down. Then jump started and everything ran fine even at high rpms. Drove for about 30 minutes turned off and would not restart.

Battery cables connecting to terminals are clean. Radio works, I think the most puzzling to me is the engine cut out. Is that typical for a alternator problem-Particularly at night - I am thinking it is because the headlights are pulling some voltage?

Answer 1

1988 Ford Bronco we're talking about here. I had a problem like that where it would just cut out on me and take 25-45 minutes to fire back up. The problem seemed even worse in humidity and rain. What it ended up being (for me) was the Ignition Control Module on the distributor. It's connection was lost due to corrosion I believe and a new ICM fixed the problem.

I'd recommend this website too. These are the guys who eventually lead me to believe it was my ICM.

http://www.ford-trucks.com/forums/index.php

It's an incredible resource for Ford Trucks...over 300,000 owners, so I figure, someone has to know, right?

Answer 2

Your problem description is a bit ambiguous..Take a look at the BLACK battery cable. Attached to the lead connector. There you will find the black cable and in addition there is a small ( 12ga.) wire. It has been a problem with corroding in the lead terminal. Check it real close. If it has corroded off or is real mangy looking cut it off and install the appropriate terminal end and put it under the terminal bolt..If that looks OK then take real close look at all the wiring under the hood..I've found a lot of problems, on Fords, involving the computer and fuel pump relays. Left side top fender pan....Check the connectors on the plug for each..I have found some that looked good but were corroded where the wire goes into the female connector..See what you find..Good luck

Answer 3

When you put the new battery in, did you scrape all the scale from the inside of the cable terminal that slides onto the battery post?

That crud will give the alternator bad readings, and create a barrier for high energy draw durring starting of the truck.

Your radio, and stuff will work, but the starter won't because it can't draw enough amps.

Answer 4

The voltage regulator is shot and that is inside the alternator so you have a choice to make, just change the voltage regulator for $10. or change the whole alternator which is the easiest to do. If you don't do your own work just have the whole alternator replaced as that will be cheaper by the time a mechanic tears the alternator apart and replaces the regulator.

Answer 5

this happened to me before at first i just thought the battery died but after i recharged it it died again then when i checked it, it was the battery contact the contact was melted from the acid the altenator was working it prouduced power to charge the battery but with a busted contact the extra power has no where to go and that can fry your cars computer. it's that or you need a new altenator.

Answer 6

try changing the voltage regulator, I had the same problem on a 1970 Chevy c10 custom deluxe and when I changed the voltage regulator it worked great if you have any more questions you can e-mail me at ricky_austin85 @yahoo.com

Answer 7

crank truck if you can rev it up a little bit take off a battery cable if car dies altonator or regulator is bad regulate is front right behind head lights

Answer 8

Yup, sounds like alternator, or voltage regulator. Or both--when one goes bad it can kill the other.

Answer 9

i would get the alternator checked