alt guage problems
Thread Starter
|
More Turbo
Joined: Feb 2011
Posts: 540
Likes: 3
alt guage problems
My alt guage doesn't seem to be working. If I turn my lights on and off you can see the needle twitch just a hair if you watch real close but it basically just stays centered. I even tried unhooking the battery, the alternator, and even the voltage regulator but the guage never moves. What should I be checking? How do I test the guage? Any ideas?
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
Ford Ammeter Gauges: Do They Work? | MILEPOSTS Garage (Tech Tips)
Thread Starter
|
More Turbo
Joined: Feb 2011
Posts: 540
Likes: 3
It's "working", the needle never did move much, if at all, read below...
Ford Ammeter Gauges: Do They Work? | MILEPOSTS Garage (Tech Tips)
Ford Ammeter Gauges: Do They Work? | MILEPOSTS Garage (Tech Tips)
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Never run an engine with the battery disconnected. This can make the alternator output float above 14 volts and fry any onboard electronics (including the ignition module). You are lucky that nothing happened.
Thread Starter
|
More Turbo
Joined: Feb 2011
Posts: 540
Likes: 3
Depending on where you disconnected things, you won't see any needle deflection in these two cases because the current through the shunt is zero. The only reason you see a "flicker" when you turn the headlights on is because of the delay in between the time you turn on the headlights, and when the voltage regulator is able to make the alternator respond. This principle is called load regulation and it is relatively poor with externally-regulated alternators, especially if the voltage regulator is the original electromechanical type.
Never run an engine with the battery disconnected. This can make the alternator output float above 14 volts and fry any onboard electronics (including the ignition module). You are lucky that nothing happened.
Never run an engine with the battery disconnected. This can make the alternator output float above 14 volts and fry any onboard electronics (including the ignition module). You are lucky that nothing happened.
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
HEI is an ignition module.
Trending Topics
More Turbo
Joined: Mar 2012
Posts: 724
Likes: 26
From: Southeast Salt Lake, UT
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Thread Starter
|
More Turbo
Joined: Feb 2011
Posts: 540
Likes: 3
More Turbo
Joined: Mar 2012
Posts: 724
Likes: 26
From: Southeast Salt Lake, UT
The F100V uses the original face. Follow the link to his page and you can get that one or the one with the new face F100VO.
Senior User
Joined: Jul 2011
Posts: 270
Likes: 0
From: North West
I'm not sure why you all say an ammeter is useless? If the meter is working correctly it is very useful showing you whether the electrical system is charging or discharging by measuring the amps going through the wire. Where a volt meter is simply showing you the amount of volts in the system with no way to tell you whether your charging or discharging.
Volt = potential Amp= intensity
Volt = potential Amp= intensity
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
I don't believe anyone is saying an ammeter is useless per se, we're just saying the factory ammeters in our trucks are useless.
More Turbo
Joined: Mar 2012
Posts: 724
Likes: 26
From: Southeast Salt Lake, UT
<12v with the engine off= Batt is going bad (my case right now)
<13.5-14.5v engine running= alt is going bad.
12-12.5v engine off= batt is good
13.5-14.5v engine running = alt is good and charging
If you see the gauge go up to 14.5v then settle down to 13.5v you know the alt is good and has completed charging the batt.... and the regulator is good.
I'm not sure what the issue is with the ammeters in Fords but even if they do change readings it isn't enough to notice while you are operating a vehicle. An idiot light is better than the factory ammeter unless your battery is going bad, then both are useless. I don't know why Ford insisted on putting them in their vehicles for so long unless someone in Ford family designed the thing and the engineers and managers didn't want to say no.