Where does your ammeter sit? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

SeeTen · 10-26-2012, 04:24 PM

Hey all!

As the title would suggest, I just got to fixing my non-woring ammeter by simply replacing the two SFE 4Amp fuses in the engine bay. The gauge used to sit right in the middle and not move a bit, but now it sags down when cranking and jumps up past the middle once it's all fired up.

My questions is, where do your ammeters sit? Mine is just about half a centimeter above the middle at idle - I was expecting a more sizable jump than that. Anyone have an ammeter that acts differently?

Thanks a bunch!

SS Tim · 10-26-2012, 06:33 PM

Sounds loke it is working fine. Think of the center as a balance point. When it starts trending to the left you are using more than yoou are making. Not bad when you are starting but something to watch while you are driving. When it goes the other way the alternator is making more than you are using and thus charging the battery. When you start moving this is a good thing. If it stays there or climbs while driving time to look things over. Now there are times like sitting at a light with the blower or A/C going along with the lights that the needle will really sag but start working its way back to center. This just is showing the system is working but if it gets worse over time your battery might be going south on you.

71K20chevy · 10-26-2012, 07:57 PM

Honestly I never notice mine moving at all

Andy4639 · 10-26-2012, 08:30 PM

You have to remember these are current flowing meter's. So as stated when u crank the truck you are drawing from the batteries reserve. Needle goes down until the truck starts then the alternator kicks in more current flowing to build the battery back up. Needle should go back to the right of mark.
This is normal and it barley being to the right of the half mark is correct for a good charging system. If you watch it real close turn everything on high and see if it doesn't drop then pick back up. Then turn everything off and it should go back to normal barley over the half mark. It's showing the system flowing either good are bad depending on the needle reference to the half mark on guage face. To the right is good and to the left is bad if the truck is running.

10-26-2012, 04:24 PM	#1
SeeTen Registered User Join Date: May 2012 Location: Southern Cal. Posts: 39	Where does your ammeter sit? Hey all! As the title would suggest, I just got to fixing my non-woring ammeter by simply replacing the two SFE 4Amp fuses in the engine bay. The gauge used to sit right in the middle and not move a bit, but now it sags down when cranking and jumps up past the middle once it's all fired up. My questions is, where do your ammeters sit? Mine is just about half a centimeter above the middle at idle - I was expecting a more sizable jump than that. Anyone have an ammeter that acts differently? Thanks a bunch!

10-26-2012, 06:33 PM	#2
SS Tim Registered User Join Date: Aug 2010 Location: Edwards, CA Posts: 7,503	Re: Where does your ammeter sit? Sounds loke it is working fine. Think of the center as a balance point. When it starts trending to the left you are using more than yoou are making. Not bad when you are starting but something to watch while you are driving. When it goes the other way the alternator is making more than you are using and thus charging the battery. When you start moving this is a good thing. If it stays there or climbs while driving time to look things over. Now there are times like sitting at a light with the blower or A/C going along with the lights that the needle will really sag but start working its way back to center. This just is showing the system is working but if it gets worse over time your battery might be going south on you. __________________ Thanks, Tim * VIN/Model Decoders * Power Team Charts (engine/transmission/gear ratio) * Post Your Pickup SPID Blazer SPID Suburban/Panel SPID * RTFM ... Read The Factory Manuals... download 'em here Highlanders Do you have a 1972 Plaid Pickup? Plaid Blazer ** Plaid Suburban

10-26-2012, 07:57 PM	#3
71K20chevy Registered User Join Date: Jul 2012 Location: Ft Wayne Indiana Posts: 1,204	Re: Where does your ammeter sit? Honestly I never notice mine moving at all __________________ 71 K20 64 GMC mud truck

10-26-2012, 08:30 PM	#4
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: Where does your ammeter sit? You have to remember these are current flowing meter's. So as stated when u crank the truck you are drawing from the batteries reserve. Needle goes down until the truck starts then the alternator kicks in more current flowing to build the battery back up. Needle should go back to the right of mark. This is normal and it barley being to the right of the half mark is correct for a good charging system. If you watch it real close turn everything on high and see if it doesn't drop then pick back up. Then turn everything off and it should go back to normal barley over the half mark. It's showing the system flowing either good are bad depending on the needle reference to the half mark on guage face. To the right is good and to the left is bad if the truck is running. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

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