Pictures of both AMP gauge fuse locations? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

demian5 · 01-11-2017, 02:23 PM

I shorted my amp gauge when working on my cluster and the fuse by the junction block broke when I pulled the holder apart. I replaced it but the gauge still isn't working. I have heard of a 2nd fuse but on externally regulated vehicles. I have a 70 with internally regulated alternator. Does anyone have a picture of where this 2nd fuse holder is on my model??

Thanks!

**LockDoc** · 01-11-2017, 02:26 PM

Quote:

Originally Posted by demian5

I shorted my amp gauge when working on my cluster and the fuse by the junction block broke when I pulled the holder apart. I replaced it but the gauge still isn't working. I have heard of a 2nd fuse but on externally regulated vehicles. I have a 70 with internally regulated alternator. Does anyone have a picture of where this 2nd fuse holder is on my model??

Thanks!

There are two small 4 amp fuses that feed the amp gauge, they are in small black rubber fuse holders at both corners of the core support by the fenders.

LockDoc

demian5 · 01-11-2017, 02:56 PM

Quote:

Originally Posted by LockDoc

There are two small 4 amp fuses that feed the amp gauge, they are in small black rubber fuse holders at both corners of the core support by the fenders.

LockDoc

Cool i'll look for the other one! Thanks!

Now to figure out how to install a 1-wire alternator AND keep the gauge working.

demian5 · 01-12-2017, 12:10 PM

Found the one on the driver side. It was blown as well. Replaced it and the gauge works again! Stoked!

davepl · 01-12-2017, 03:41 PM

Quote:

Originally Posted by demian5

Cool i'll look for the other one! Thanks!

Now to figure out how to install a 1-wire alternator AND keep the gauge working.

You can't. Unless you in turn convert the alternator to 3-wire (that's what I did on my LS setup, but the alternator had the connections for it I just had to make the harness changes). So I'm totally confused by your comment that the gauge works, unless you haven't actually installed the one-wire alternator yet?

You could convert the ammeter to a voltmeter, I think someone on the board even sells a kit. It'd be more informative, accurate, and best of all it'd work!

72blu · 01-12-2017, 03:52 PM

Quote:

Originally Posted by davepl

You can't. Unless you in turn convert the alternator to 3-wire (that's what I did on my LS setup, but the alternator had the connections for it I just had to make the harness changes). So I'm totally confused by your comment that the gauge works, unless you haven't actually installed the one-wire alternator yet?

You could convert the ammeter to a voltmeter, I think someone on the board even sells a kit. It'd be more informative, accurate, and best of all it'd work!

I recently did a LS swap on my 72 and was a little confused on what do to with the external regulator. I tried following a guide on the forums here but i'm still not sure how to properly delete it. Anyway you could clarify what you did ?

davepl · 01-12-2017, 04:37 PM

I was using the LS3 eRod wiring harness, so it gets tied to the battery, and the main lead from the alternator goes to the junction block. It has the sense wires if you can use them, so I just went ahead and used them. That means that NONE of the original wiring was retained or modified, and the old regulator is still sitting on the firewall. So my case likely doesn't help you much, sorry.

There are a ton of threads on the basic external regulator to internal conversion. It's cut two wires and loop two others together, pretty easy, if that's what you're after.

**Wrenchbender Ret** · 01-12-2017, 05:38 PM

Changing the alt. wireing will have no effect on the ammeter.

**dmjlambert** · 01-12-2017, 09:51 PM

I agree. The ammeter measures the current flowing one direction or the other along the red wire that goes from the battery junction block to the front driver-side fender area. As long as your alternator connects to the red wire at the driver-side fender area, and you continue to use that same 12 gauge red wire, the ammeter will work fine and show battery draw or charging.

Andy4639 · 01-12-2017, 10:02 PM

Mad electric is all you need.

Read this and see why 3 wires is better than one.

http://www.madelectrical.com/electri...hreewire.shtml

**Whamp48** · Yesterday, 08:24 PM

Quote:

Originally Posted by davepl

You can't. Unless you in turn convert the alternator to 3-wire (that's what I did on my LS setup, but the alternator had the connections for it I just had to make the harness changes). So I'm totally confused by your comment that the gauge works, unless you haven't actually installed the one-wire alternator yet?

You could convert the ammeter to a voltmeter, I think someone on the board even sells a kit. It'd be more informative, accurate, and best of all it'd work!

I put one of those kits on, now my temp gauge don't work.

**kwmech** · Yesterday, 08:47 PM

After 50 years the small glass fuse is PITA. Just partially rewired a customers truck and changed them over to a spade fuse with the internal alt. I pull the wires out of the voltage reg connector and eliminate the blue and white. Left over with red and brown. Hook a single connector to each of them then to the alt connector. Been doing it for years this way. Want to go back to OE someday? save what you take off and put it in a baggie. Easy peasy. Priced out a regulator and alternator at over 120.00. Got the updated one for 58.00 and moved a couple of wires. Had to re-clock the new alternator though so the wires weren't hanging above the ex manifold

**dmjlambert** · Yesterday, 08:52 PM

Well, I don't think glass fuse or spade fuse in the ammeter wiring would have anything to do with the temperature gauge. You have a blown fuse or disturbed some wiring or disturbed something on the instrument cluster related to the temperature gauge.

**Accelo** · Today, 06:38 PM

Changing the alt. wireing will have no effect on the ammeter. "

Maybe not. However, typically installing a one wire alternator is for extra capacity. It is installed for options like electric fans or power seats. You should not be running 100A through a 12 gauge wire.
The old school amp gauge is run on the "shunt principle". Both sides of the factory amp gauge have 12V. The amp gauge is, in reality, a micro volt gauge that is calibrated in amps.

Because of the low voltage difference between the connections they have to be perfect. I have repaired many a amp gauge by cleaning the terminals. Starting with the connection at the small black terminal and continuing to the connections at both fuses.
The system is temperamental because of this and is one of the reasons GM discontinued the shut amp gauge in favor of the voltage measurement.

01-11-2017, 02:23 PM	#1
demian5 Registered User Join Date: Aug 2016 Location: Lake Forest, CA Posts: 2,177	Pictures of both AMP gauge fuse locations? I shorted my amp gauge when working on my cluster and the fuse by the junction block broke when I pulled the holder apart. I replaced it but the gauge still isn't working. I have heard of a 2nd fuse but on externally regulated vehicles. I have a 70 with internally regulated alternator. Does anyone have a picture of where this 2nd fuse holder is on my model?? Thanks! __________________ "Work hard, use your vacation days." 1970 C15 GMC Long Bed 1986 C20 Scottsdale 1983 K2500 Sierra Classic Suburban 6.2 Instagram: C10sofOC

01-12-2017, 12:10 PM	#4
demian5 Registered User Join Date: Aug 2016 Location: Lake Forest, CA Posts: 2,177	Re: Pictures of both AMP gauge fuse locations? Found the one on the driver side. It was blown as well. Replaced it and the gauge works again! Stoked! __________________ "Work hard, use your vacation days." 1970 C15 GMC Long Bed 1986 C20 Scottsdale 1983 K2500 Sierra Classic Suburban 6.2 Instagram: C10sofOC

01-12-2017, 04:37 PM	#7
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: Pictures of both AMP gauge fuse locations? I was using the LS3 eRod wiring harness, so it gets tied to the battery, and the main lead from the alternator goes to the junction block. It has the sense wires if you can use them, so I just went ahead and used them. That means that NONE of the original wiring was retained or modified, and the old regulator is still sitting on the firewall. So my case likely doesn't help you much, sorry. There are a ton of threads on the basic external regulator to internal conversion. It's cut two wires and loop two others together, pretty easy, if that's what you're after. __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

01-12-2017, 05:38 PM	#8
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,197	Re: Pictures of both AMP gauge fuse locations? Changing the alt. wireing will have no effect on the ammeter.

01-12-2017, 09:51 PM	#9
dmjlambert Senior Member Join Date: Apr 2016 Location: Cypress, TX Posts: 3,615	Re: Pictures of both AMP gauge fuse locations? I agree. The ammeter measures the current flowing one direction or the other along the red wire that goes from the battery junction block to the front driver-side fender area. As long as your alternator connects to the red wire at the driver-side fender area, and you continue to use that same 12 gauge red wire, the ammeter will work fine and show battery draw or charging.

01-12-2017, 10:02 PM	#10
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: Pictures of both AMP gauge fuse locations? Mad electric is all you need. Read this and see why 3 wires is better than one. http://www.madelectrical.com/electri...hreewire.shtml __________________ 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.

Yesterday, 08:47 PM	#12
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,438	Re: Pictures of both AMP gauge fuse locations? After 50 years the small glass fuse is PITA. Just partially rewired a customers truck and changed them over to a spade fuse with the internal alt. I pull the wires out of the voltage reg connector and eliminate the blue and white. Left over with red and brown. Hook a single connector to each of them then to the alt connector. Been doing it for years this way. Want to go back to OE someday? save what you take off and put it in a baggie. Easy peasy. Priced out a regulator and alternator at over 120.00. Got the updated one for 58.00 and moved a couple of wires. Had to re-clock the new alternator though so the wires weren't hanging above the ex manifold Attached Images

Yesterday, 08:52 PM	#13
dmjlambert Senior Member Join Date: Apr 2016 Location: Cypress, TX Posts: 3,615	Re: Pictures of both AMP gauge fuse locations? Well, I don't think glass fuse or spade fuse in the ammeter wiring would have anything to do with the temperature gauge. You have a blown fuse or disturbed some wiring or disturbed something on the instrument cluster related to the temperature gauge.

Today, 06:38 PM	#14
Accelo Senior Member Join Date: Mar 2015 Location: washington Posts: 2,201	Re: Pictures of both AMP gauge fuse locations? Changing the alt. wireing will have no effect on the ammeter. " Maybe not. However, typically installing a one wire alternator is for extra capacity. It is installed for options like electric fans or power seats. You should not be running 100A through a 12 gauge wire. The old school amp gauge is run on the "shunt principle". Both sides of the factory amp gauge have 12V. The amp gauge is, in reality, a micro volt gauge that is calibrated in amps. Because of the low voltage difference between the connections they have to be perfect. I have repaired many a amp gauge by cleaning the terminals. Starting with the connection at the small black terminal and continuing to the connections at both fuses. The system is temperamental because of this and is one of the reasons GM discontinued the shut amp gauge in favor of the voltage measurement.



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