had alt. replaced in '93 F-150 a while back... stopped charging on way home from work one day. just more recently I noticed slow starting when cold so had battery replaced. Today I had to drive the truck in a cold rain so I had lights, wipers, defrost, etc. on. At idle in gear volt gauge would drop to about "O" in "NORMAL" where it usually sits between "M" and "A" (sorry, no voltage readings - didn't have meter with me.) Should I be worried, or is this normal? I have to say I don't particularly like it, as stop and go traffic is not particularly uncommon around here (DC-land.) If it's NOT normal, where can I get a GOOD alternator?
Nate, it may or may not be normal. If you have a good alternator/starter shop where you live, that is where I would take it. They can test the whole system.
I have had a lot betterluck with getting starters there than at most FLAPS.
In fact, I have had some brand new GM starters that didnt last worth a darn.
Given the sub-zero temps and 45 ft of snow on the roof of your house, I'd consider anything that runs to be normal. Wait until good weather before you get too worked up. I suspect that in good weather, the problem will go away.
that's the problem, closest auto electric specialty place I know of is
50 miles away, next closest about 70, and while I've had mostly good luck with the one 70 miles away (used to live near there) the Delco 10SI in my Studebaker which I had them rebuild for me rather than going with a parts store reman (which was kind of dumb, because they're super cheap, and I paid close to $300 to theoretically have it "done right." Next time I will mail order a kit and do it myself, now that I know the windings are OK) exhibits the same behavior. In that case I'm not 100% sure if it's a pulley mismatch or an actual fault with the alternator though.
I did have the same behavior with the original F*rd alternator on the truck and when I took it to my FLAPS (not auto electric shop, but an independent FLAPS that has since become a NAPA) to have it tested they said to run it and not worry... and it died maybe 4K miles later :/
I am just kinda paranoid as the truck is almost 20 years old and I don't want to get stranded somewhere... I try to keep everything in top shape and repair/replace anything questionable immediately, but then I run into stuff like this... I have also cleaned/greased all accessable underhood electrical connections prior to alternator/battery replacement. Not about to give up on it unless something really tempting comes along as the A/C still works, and it has fairly new (all within last 10K miles) brakes, shocks, tires, alternator, battery, fan clutch, wiper motor etc. and I also changed all fluids except for coolant (PO had just had it flushed) and P/S (been meaning to do that but haven't yet) in the same period. Only has 145K miles on it now...
Nate Nagel wrote in news:iik7ol02km1 @news7.newsguy.com:
My first approach would be to put a digital voltmeter across the battery terminals with the engine running. Have you done this?
Park the truck pointing at a wall or someplace where you can easily see the headlight beams. Rev the enngine. Do the lights get brighter as the revs rise, then dim as they drop back to idle? Try this with the accessories off and on.
I think the OP is buried under umpteen feet of snow in a climate that is a bazzilion degrees below what it takes to sustain life, and his electrical system is simply showing the strains of the environment. For lack of a better term, he needs to chill out.
That isn't going to tell him anything he doesn't already know. The lights will get brighter and dimmer. The gauge has already indicated that the voltage is changing some. The question is that because the alternator is weak or is the defroster and wiper motors or some other load drawing more than usual. Does it have fog lamps? Is the idle lower than normal?
Unless it is a heavy duty alternator these things only put out about
Not today, it was about 30 degrees and raining and I had stuff that needed to be moved. Normally I would have...
accessories off I don't think it's dropping off much, but acc's on they seem to. Idle in Drive is about 600-700 RPM if the tach in the dash is to be believed.
you need to put a meter on the battery while the motor is running to see what your charging volts are.. Anything below 13.5v you should replace the alternator.
And if in fact the problem IS just a matter of the severe cold, then upgrading to a heavy duty alternator may be a solution. Because next winter is going to be cold too.
I wouldn't call this "severe cold" after all it was only raining, not snowing or freezing. But I am going to have a hard time "troubleshooting" it as it pretty much lives in the parking lot at work when I'm not driving it (long story.)
On Sat, 05 Feb 2011 14:49:57 -0800, Jeff Strickland rearranged some electrons to say:
Measuring the alternator output will tell you if it's is charging the battery or not. In the real world, a properly functioning alternator will charge the battery no matter how much snow is on the ground.
Dash gauges are worthless at best. Totally misleading usually.
Get a good, accurate, volt meter (VOM, DVOM) and measure the battery voltage with that. You should have about 13.8 volts DC when engine is running. If it drops below 13.2 volts, then there is a problem with the charging system, battery or cables/connections.
Also don't throw parts in without proper diagnostics.
The voltage dropoff, at least that I've noticed by watching the dash gauge, does not occur in Park or Neutral because apparently the engine is spinning faster enough that the alt. isn't working as hard...
It is not NOT CHARGING, it simply moves the needle due to the heavy load and cold temps. My guess is that the battery suffered because of the cold too.
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