Question about 1988 Ford F 150

1 Answer

Alternator gauge shows discharge

New bat and my charger shows 100 on alt but gauge shows discharge

Posted by on

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Top Expert:

    An expert who has finished #1 on the weekly Top 10 Fixya Experts Leaderboard.


    An expert that got 20 achievements.


    An expert that got 10 achievements.

  • Ford Master
  • 21,873 Answers

Not sure I follow the story. The alternator is charging 100amps but the gauge shows less than 14 volts ? Is the alternator output at least 13.5 volts and is that getting to the battery ?

Posted on Feb 15, 2014

6 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

  • 295 Answers

SOURCE: is there a fuse/fusible link to alternator,

The wiring burning up at the altenator most likely caused the diode inside the altenator to short out. I would just replace the altenator now.

Posted on Mar 18, 2009

  • 667 Answers

SOURCE: 1998 explorer intermintant start. New starter.

intermittant start sounds like starter relay, 13.6-14.4 is still charging anything above 12.0 is charging, so that does not sound bad to me. I have a 99 F150 and have found all my problems were sticky relays

Posted on Mar 23, 2009

  • 32 Answers

SOURCE: 1996 aerostar charging problem.Replaced alt

I recently went through a battery/charging episode. Not to sound like the wise-guy, But! try a good battery and see what kind of reading(s) you can get.
Let me know if this is of help to you.

Posted on Oct 01, 2010

  • 75822 Answers

SOURCE: 03 taurus, new alt, bat charging @ 14.2v, w/ load

Is this a new Alternator a rebuilt? If it is a rebuilt is it a Motorcraft OEM rebuilt? If it came from any of so called discount auto parts dealers I'd be highly suspect of the Alternator being the problem. What you are describing his a failing diode in the rectifier or a poor connection somewhere inside the Alternator. My own brother good 4 bad Alternators from Kragen and finally gave up and bought a ACDelco unit. This is not an uncommon story.

Posted on Sep 15, 2011

  • 334 Answers

SOURCE: 03 Taurus, battery light comes on. R&R bad alt &

You may have a a/c voltage leak comming from the alternator..If its a rebuilt alternator sometimes you get a bad one ..But make sure all your connections are good ecspecially the small wires coming out the back ..These are the field and sensor wires..Plus make sure all your grounds on the vehicle are not broken or missing..You can have good voltage but it may have a drop going to the computer because of a ground and cause the light to come on

Posted on Sep 15, 2011

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

2 Answers

Battery warning light turn on what could be the problem

Clean battery terminals first. If still no better, get parts store to test alternator.

Jul 06, 2014 | 2012 Jeep Grand Cherokee Laredo 4dr SUV...

1 Answer

Amp Gauge goes all the way past the highest number

amp gauge, and you forgot high number, 30, 60 , 80 , 100 amps?
and did it go left or right, one way is discharge other is charging.
key facts all.?????
no year,
no statement of , if car is stock or not.
if someone added a gauge, here,

back in the olden days, before the way better volt meter.
they had Amp gauges, many we ADD on.
most are wrong size. too. and installed WRONG. (ask correct way)
if the alt dies, the ammeter goes negative amps showing disgnarge ammount,
when runing right it ill be in the posative direction, charging battey
or at 0amps, battery is charged.
all this depends on how its installed.
if put in the alternator lead (big) it will only show alternator output.
10 to 50amps, 10 is typical. 50 be dead battery, running.

Feb 23, 2014 | Jeep Cars & Trucks

1 Answer

New battery not charging after changing the alternator

First make sure both battery cables are free of corrosion and ground is secured to chassis and engine then check to see if theres an alt. fuse or bat. fuse blown. Another way to test charging sys w\out an meter is to remove the ground terminal from the bat. with the car running, if the alt. is good car stays running, if all else fails take the alt and bat to a parts store that will test them for free

Dec 14, 2013 | Chevrolet Venture Cars & Trucks

1 Answer

Amp meter in truck says 12 amps when truck is running. Brand new alternator and brand new battery. Charge reads 13.5 when on hand heldmeter at O'riely but in truck it says low. cable from pos. bat. ...

It is not unusual for the cluster gauge to be off a little or out of calibration, specially on older vehicles. You could have a voltage drop at the starter, corrision, bad wires or bad connection would cause it.
The 13.5vdc at the battery is a bare minimum though and could be a potential problem. With all your lights on and blower motor on high it could even be discharging.
I would check all your cables, and look closely at the grounds. Grounds to engine and frame. Also inspect the cables, lot of times when they corrode on the ends, the corrision will continue down the cable, like a cancer eating away, you can't see it because of the insulation...but it happens.
Good luck, i hope this helps.

Jul 16, 2011 | Chevrolet Silverado 1500 Cars & Trucks

1 Answer

Battery bran new, Alternator brand new. Bat light dosent come on when key is turn on. Both Bat and Alt are checked works fine. Power test showes the Alt is recieving and sending power. The issue is the...

I would start at the positive terminal on the battery. Is there a separate wire to the clamp carrying the current from the alternator? It should have a fusible link in it (may not be obvious, could be just a thick spot in the wire). If the problem is not there, you will need to trace that wire forward, checking for voltage everywhere the wire is visible (poke a sewing pin through the insulation to get voltage reading)..

Mar 14, 2011 | 1984 BMW 3 Series

3 Answers

Replaced alternator but charging indicator on dash shows less then nominal battery is new could it be a relay don't have a chiltens so please explain carefully thanks

did the alternotor come with a new pigtail?those big rectangal connectors that plug into the alt go bad all the the guages on them are notorios for lying check with a volt meter?at night turn on headlights aimed at wall notice brightness start motor,note brightness when engine starts if brighter then alt works

Mar 19, 2010 | 1997 Ford Ranger SuperCab

2 Answers

1989 Ford F250 7.3L Diesel. Bat light came on then smoked the VR

Thats a guessing game, but first, if the battery light was on, that means no alternator output. So recharge the batteries and be sure they are good, Then replace the alternator. If the batteries and the alt are good, and the battery light is off, then all should be OK.

Nov 15, 2009 | 1992 Ford F250

1 Answer

Need wiring diagram for 1967 camaro v8 changed from external regulator to alternator with internal regulator

I am assuming you are now using a 1976 style GM alt.
The most common and popular model.
You need one 10 gauge wire from the battery to the alternator output.
This can be run directly from the battery +.
Run a short 10 gauge wire from alt output to large wire at regulator plug on alt.
Run small wire on alt reg plug to Bat light wire.
A new alt regulator plug pigtail can be bought at any parts store and is recommended.

The existing regulator should have the connections marked.
One of those wires will be the bat light wire if needed.
If you have a amp meter or voltmeter in the vehicle.....use your existing large output wire (usually red) to hook up to the new alt output connection.

Sep 15, 2009 | Chevrolet Camaro Cars & Trucks

1 Answer

Just installed a new alternater and the battery gadge is reding discharge I had the battery checked and its good. Can you help

Check the 'Bat' / 'Charge'/ 'Alt' indicator on the dash panel lights when the vehicle ignition is switched on prior to starting the engine.
This indicator should extinguish within approx 1 second of starting engine.

If the indicator is not operating the alternator cannot provide charge current - check:-
1) the wiring connections to the new alternator,
2) the indicator lamp is not blown,
3) the alternator is properly grounded.

If the indicator light works normally, check the output voltage of the alternator is approx 14.5v when the motor is running.
If its about 14.5v, the battery should be charging.

Aug 12, 2009 | 2003 Chevrolet Tahoe

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

122 people viewed this question

Ask a Question

Usually answered in minutes!

Top Ford Experts


Level 3 Expert

75822 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers


Level 3 Expert

5501 Answers

Are you a Ford Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides