99 ford fi50

[man22]

I was pulling a trailer uphill and hit 3900 rpm when my battery light started flickering. As in cleared 4000 rpm it came on solid until the rpm's were back under 3900. I've been told that it is probobly the alternator arm wiggling at the higher rpm and not making proper contact.The truck also had the same problem without a trailer as well.Any ideas????( Aside from it's a ford so shoot it.)

[Mr T]

It's a ford.. time to shoot it.. oh wait......

You can pull the alternator and Autozone/Advance Auto/other shops will test it for free. Some places can test it in car.

Check your belt tightness.. If its too tight you may have taken out your bearings. I would take it in to test, you can usualy hear right away if its a bearing going.

[Roger]

My gosh....such disrespect for the best truck on the road. News Flash!!! It aint the trailer!!!!
How about we take a look at how the f150 charging system works..... With the ignition in the "on" position voltage is applied on the warning indicator circuit, this in turn energizes the voltage regulator internal to the generator (you can call it an alternator if you like) When the regulator comes on line this allows current to flow on the battery sensing circuit to the generator field coil. Once the engine is running the generator produces AC current which in turn is converted to DC current (reason technically it isnt an alternator) thru rectfiers and distributed via a series of diodes. This DC current the exits the generator thru the B+ terminal (the one with the boot on it) to the vehicles electrical system. Now that the generator is producing current a voltage sense or signal is taken from the generator stator and is sent to the regulator. This "feedback" signal (approximately half battery voltage) is used to open the relay turning the warning light off. Simply put if you have a voltage drop at the battery below base values then the sensing circuit will turn on the warning light.
So first thing is to get the battery load tested usually free of charge at the local auto-supply. Then reinstall and go thru the relearn steps for the vehicle. Next do a no-load generator test. Turn every thing off on the vehicle. Operate the engine at 2000 rpm connect a volt meter positive lead to the B+ terminal on the back of the generator and negative lead to ground. Should read 13 to 15 volts. Now check if battery is recieving charge. Turn on the headlights (high beam), a/c on and blower on high. Connect the voltmeter across the battery (correct polarity) get the voltage reading at idle. Now increase to 2000 rpm. You should have a minimum of 0.5 volt increase in voltage above the base voltage. If not suspect a bad generator. Now if all this checks out then suspect a circuit problem or fuse loose problem in the sensing circuit causing the warning light to flicker or illuminate even though all else is checking normal.
I'd much rather shoot a chevy!! sniper_1

[mdshunk]

AND... watch out for sticker shock when you buy the alternator. I had to get one for my ford truck about 2 years ago and it was about 320 bucks for a rebulit one. I took the old one apart first for educational purposes and found the brushes worn down to nubs and one was stuck in the brush holder and only making intermittant contact. This intermittant contact pretty much thrashed the armature coms.

Doesn't anyone make rebuild kits for alternators anymore? I checked for mine at the time and was told that none were available. Seems like I could have turned the armature a bit and slapped come bearings and brushes in it and been good for another 100,000 miles.

[Mr T]

My gosh....such disrespect for the best truck on the road.
............
I'd much rather shoot a chevy!! sniper_1

I no longer have much brand loyalty for vehicle manufacturers. Ive had major problems with Chevy, Ford and Dodge/Chrysler. My service vehicle is currently a Toyota, and I have pretty much beaten the crap out of it. Its been the most reliable / least expensive to operate vehilce Ive had yet. I drive 45k miles a year with a very poor milage reimbursement.

When you get your battery tested. Ive seen 2 different battery testers around.. One is a hand held box with a meter and 2 clips hanging off it.. It is basicaly a big resistor in it. Ive had bad batteries test good on them. Many auto places have a fancy tester that when they are in a good mood will wheel out. It checks more aspects of your battery, different loads, charging capacity, and will top it back off with a quick charge. It is a far better tester, ask if they have one when they bring out the cheese grater tester. Batteries are cheaper then a tow, if in doubt and it has a few years on it...replace.

Ive seen very few rebuild kits on modern alternators. Seems like they make them so you cant take them apart anymore. I know in the 80's you had to insert special pins on GM alternators before you seperated the halfs or the brush assemblies would fly out and you cant get it back to gether (big suprise huh?)

If you live in a big city area and can afford to be without a truck for a day or 2, you may want to check into a automotive electric service center, they may rebuild it for you... cheaper then a rebuilt replacement.

[mdshunk]

My service vehicle is currently a Toyota...
Sorry to learn that. And to think that I liked you up until now.

[Note to self: Add Mr. T to list below Ohm's name]

[Mr T]

I had a S-10 previously.. I spent more repairing it then I did on payments.. I finally traded it in at a loss to cut my losses.. What good is it when it sits in your driveway? The fuel pump went out... specific to that model year (97). Every model year above it had its own pump. It took me 3 weeks to FIND one. I finally got one for $350. Every dealer had to special order it for close to $600. Autozone could not get one period. Advance auto's nearest one was in Georgia, and they still couldnt get it.

The clutch started to fail, same problem, parts were specific to that model year only.. I never fixed it.

I was putting 80-100$ in the gas tank a WEEK. (I drive 45k miles a year). I almost bought a Ranger as a replacement, but talked to a few other techs who had them at work, and calculated that it would cost me that much or more in gas to operate it. Not to mention, the dealer of the one I almost bought, refused to fix the AC in it so I walked. It sat for many weeks still.

The Toyota I have takes standard tools to work on, any parts that I need are readily available. No tricks to make you take it to a dealer. It handles great in rough/off road situations. And gets close to 30mpg on the highway, fully loaded.

IF you are bashing the American car thing. Ohio has overtaken Michigan for automotive manufacturing. A good percentage of Toyotas and Honda's are made in Ohio. I have several friends who work for Honda. We have lost several customers at work who are GM automotive suppliers... WHy? THey relocated to Mexico. I owned a Civic a while back that had a higher percentage of Ohio made parts, then a S-10 (different one) had of US made parts. Also Chrysler is now owned by a German company. Ford is a majority owner of Mazda. GM owns Saab now. bla bla bla bla bla

[Roger]

I'm surprised anyone is still trying to make that argument that the foriegn vehicles are better, especially pickups. But I realize its a waste of time to argue this point. Ford and Chevy and Dodge outsell these "phony" trucks by many many thousands of units both full size and mid-size....I think that speaks for itself.
I dont like you anymore either I'm taking you off my buddy list ....... puke_1

[Mr T]

Well at least my IP isnt blocked yet :D (and I'm glad im on DHCP)

I'm not saying they outright are better.. (and mine is really a SUV). It just fits my purpose.. If i was hauling more weight, playing off road more, and driving less, a 'real' truck would fit me better. With the line of work I do, you get killed financialy if you drive a big truck. We get paid crap for milage reinbursement.

HOpe i didnt offend too much

[Roger]

I dont think you can offend anybody on this site except OHM 1 ....heck.... I think Marc even enjoys being offended.

[greystreak92]

www.ford-trucks.com If there ever existed a better group of people and resources for Ford enthusiasts, I haven't found it. Just a suggestion to the happy Ford owners. I dont' wate my time arguing over which vehcile is "better". They are like politicians anyway... lesser of many evils. Somewhere along the way someone will have a had a bad experience with ANY vehicle you mention.

(But off the record, I use Toyota's and the rest of the rice-burner phylum as speed bumps)