Where does your voltmeter run at?

[BrandonMag]

The reason I'm asking this question is because I've had intermittent problems with the voltmeter/batt. light since I bought my truck.

When I was driving it home from the place of purchase, I noticed the battery light flickered on a couple of times. The voltmeter ran right around #1 on my in-expertly drawn voltmeter gauge:

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I figured it would be something I'd look into at a later time. Over the past couple of months the battery light has only come on a couple of times. I had the charging system tested about two weeks after I bought it. The batteries were fine, but the tester briefly said the charging system was low while it was cranking, and then indicated normal. Hmmm.

So I figured it was the alternator. I finally got around to pulling it out and having it tested yesterday. It put out 14.68 volts. That's good, methinks. I'm glad I pulled it, though, because the bearings in it are going to need to be replaced eventually. I purchased a new voltage regulator, thinking that may raise my voltmeter level. I re-installed the alternator (along with four new belts: AC, power steering, smog pump and alternator), removed the old, corroded voltage regulator, cleaned out the pigtail leads, cleaned up the ground contact and installed the new voltage regulator. Now that I had an all-new regulator and a bench-tested alternator with new belts, I figured I'd be running good. Not so.

Upon start-up, the voltmeter didn't do anything. After about 10 seconds, it registered around #1. I revved it up to about two grand after it had run for a couple of minutes and the voltmeter didn't move. Then, when I released the clutch to take it on a drive, the voltmeter briefly went up to #3. It quickly settled at #2, where it ran for the whole 20-minute drive I took it on. Could it just be that my voltmeter is indicating slightly less volts than the alternator is actually putting out? I did connect a voltmeter across the battery leads with the engine running and it showed 13 volts.

A little backstory: this truck is hard to start cold (I've literally cranked on it for over a minute) and I've never had any problems with the batteries running low. I haven't seen the battery light come on since I replaced the regulator, but I only took it on the one drive.

 

[jperecko]

It sounds like either one or a combination of 2 issues.

Without a significant load, your alternator may put out a healthy 14+ volts... but it may be that it is not putting out the amps to back that up.

Another option could be that you have a short with your electric system somewhere which is eating juice. Check all wiring.

It could also be a combination of the 2- you might have a short which has been stressing the alternator which is causing it to fail and not put out enough amps.

 

[typ4]

start checking grounds under the dash, mine does this when they get loose. Also make sure the ground from the alt to reg base is there ,if not make one, solves many problems.

 

[jtate]

brandonmag sounds like you are having the same problem that i had with mine. after replacing three regulators i finaly found one that worked like it should. just because its new doesnt mean its good lol. it also sounds like you are dealing with gp issues. it shouldnt take 1minute of cranking for it to fire up and you dont want to crank for longer than 20 sec at a time with a 2 to 3 minute cool time in between or your next issue might be replacing the starter. how long does your WTS light stay on for? you should be looking for about 10 to 15 sec on the wts light depending on the temp outside. on my truck i cant go by the wts light i have to go by the volt gauge or listen for the click, for some reason the light goes out before the plugs are good and hot.

 

[BrandonMag]

it also sounds like you are dealing with gp issues. it shouldnt take 1minute of cranking for it to fire up and you dont want to crank for longer than 20 sec at a time with a 2 to 3 minute cool time in between or your next issue might be replacing the starter.

The gps were replaced just before I bought it. The PO told me that I could either turn the key and wait for the WTS light to go off and try to crank it, or I could cycle the gps again and it would fire up quicker. When I cranked on it for over a minute, it was about 30* outside and had been sitting for several hours. Usually, when it's above 40*, I'll cycle the gps once and crank for an average of five seconds before it fires off.
I didn't realize you were only supposed to crank for 20 seconds. I sure don't want to have to buy a new starter.

how long does your WTS light stay on for? you should be looking for about 10 to 15 sec on the wts light depending on the temp outside. on my truck i cant go by the wts light i have to go by the volt gauge or listen for the click, for some reason the light goes out before the plugs are good and hot.

The WTS light stays on for beween 10 and 15 seconds.

 

[Greenie]

My battery light flickers every so often - the solution has always been to remove the two wire connector to the alternator and clean the contacts with spray cleaner - clean the contacts with a dentist tool or small screwdriver and you ought to be good for another year or two until it gunks up again.

 

[franklin2]

My battery light flickers every so often - the solution has always been to remove the two wire connector to the alternator and clean the contacts with spray cleaner - clean the contacts with a dentist tool or small screwdriver and you ought to be good for another year or two until it gunks up again.

Yep. If you lose connection from the alternator to the white wire that plugs into the alt, it will make the bat light come on.

I finally got mine right, and the volt gauge points straight down the middle when the alternator has finally got ahead and the batteries are almost charged. If you use the glowplugs and crank it a lot, the guage will be over to the left till it catches up.

 

[BrandonMag]

Found the problem!

I took the F two fiddy in to a local auto electric mechanic and he hooked it up to his Snap-on auto electric tester. After running several tests, he told me he was about 90% sure that something was wrong with my alternator. I drove the truck home, pulled the alternator and took it back to him the next day.
Well, come to find out, one of the three soldered points where the windings are connected to the rectifer had broken, causing the winding to heat up. So later today I'm going to pick up my newly rebuilt 160 amp alternator.
Here's a question for those in the know: Am I going to need a heavy-duty voltage regualtor to go with my new (even heavier-duty) alternator?

 

[sassyrel]

nope--the reg just senses when current is needed--and adjusts accordingly--and AFTER the gps cycle off--it should set at 14.3 or a tad more--on a under the hood gauge--DONT go completely by the dash gauge

 

[BrandonMag]

DONT go completely by the dash gauge

Sage advice, sassy.
I installed the newly rebuilt alternator and was dismayed to find the gauge ran anywhere from the #1 bar shown above to the #3 bar.
I took it back to the mechanic, who once again hooked up the Snap-On auto electric tester. The alternator is working fine but the gauge is reading low. He said Ford is known for having crappy stock voltmeters.
So... it's time for some kind of solution to the stock voltmeter. Custom AutoMeter dash, anyone?

 

[Mat J]

I hanvt done this on my volt meter but have considered it. I think there has to be a way to run another wire to connect to the gauge. I think the problem with these reading low is the voltage drop in the crappy wiring ford used and they probably pull the reading off a wire that has other draw on it.

 

[typ4]

I
Well, come to find out, one of the three soldered points where the windings are connected to the rectifer had broken, causing the winding to heat up. So later today I'm going to pick up my newly rebuilt 160 amp alternator.
Here's a question for those in the know: Am I going to need a heavy-duty voltage regualtor to go with my new (even heavier-duty) alternator?

Had this happen I bet.

Second pic is the fix for high amp alt's

 

[BrandonMag]

Had this happen I bet.

Hey, how did you get ahold of my old alternator parts?

Second pic is the fix for high amp alt's

Yep, that second pic is exactly what is installed in my new alternator.