1966 C10 Ammeter reading - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Bushman66 · 10-24-2019, 06:43 PM

So, just completed my 350 for 292 swap and the final piece was hooking up the voltage regulator (all stock wiring, stock alternator from the I6, points distributor).

My question, what is the Ammeter supposed to read when driving? When I am driving around, it pegs to full charge, and then drops slightly to right of centerline (3/4 tank if you visualize a gas gauge), as i slow to idle.

When the truck is off, and all electrical is off, needle parks at centerline.

When I turn on the parking lights, engine off, the needle shows at slightly left of center (~1/4-3/8 tank to use the gas gauge analogy).

I want to be sure the voltage regulator is working, and NOT OVERCHARGING my battery. That happened on an old Mustang I had years ago and it boiled the battery and spewed acid all over my engine compartment. No Bueno.

I threw a volt meter on the battery posts at idle and it was reading ~13.5V.

Thanks!

Andy4639 · 10-25-2019, 10:27 AM

Best thing to do is check the battery with a volt meter while it's idling and see what it's putting back to the battery. Also you can take the same meter and put the red lead on any good 12 volt source connection of the fuse block and then the black lead to ground and drive it and see how it does.

From what your stating it sounds like it's working correctly. Those old gauges aren't calibrated so when charging it may go to the high side but I would check it to make sure.

Bushman66 · 10-25-2019, 12:58 PM

I figured it out, reading a post on the Corvette Forum of all places. There was a post there that stated all electrical load up thru the 68 Corvettes ran through the horn relay via a wire from the solenoid to the relay.

Looking back to my disassembly pictures, there was a wire from the positive battery cable to the horn relay. It looked like a bogus wire (non factory, non factory connectors) that was added when the prior owner added an aftermarket stereo. So I rigged up a test wire with a couple of connectors and ran it between the positive battery terminal and the hot terminal on the horn relay and...voila...ammeter now reading correctly.

10-24-2019, 06:43 PM	#1
Bushman66 Registered User Join Date: Apr 2019 Location: Phx, Arizona Posts: 131	1966 C10 Ammeter reading So, just completed my 350 for 292 swap and the final piece was hooking up the voltage regulator (all stock wiring, stock alternator from the I6, points distributor). My question, what is the Ammeter supposed to read when driving? When I am driving around, it pegs to full charge, and then drops slightly to right of centerline (3/4 tank if you visualize a gas gauge), as i slow to idle. When the truck is off, and all electrical is off, needle parks at centerline. When I turn on the parking lights, engine off, the needle shows at slightly left of center (~1/4-3/8 tank to use the gas gauge analogy). I want to be sure the voltage regulator is working, and NOT OVERCHARGING my battery. That happened on an old Mustang I had years ago and it boiled the battery and spewed acid all over my engine compartment. No Bueno. I threw a volt meter on the battery posts at idle and it was reading ~13.5V. Thanks!

10-25-2019, 10:27 AM	#2
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: 1966 C10 Ammeter reading Best thing to do is check the battery with a volt meter while it's idling and see what it's putting back to the battery. Also you can take the same meter and put the red lead on any good 12 volt source connection of the fuse block and then the black lead to ground and drive it and see how it does. From what your stating it sounds like it's working correctly. Those old gauges aren't calibrated so when charging it may go to the high side but I would check it to make sure. __________________ 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.

10-25-2019, 12:58 PM	#3
Bushman66 Registered User Join Date: Apr 2019 Location: Phx, Arizona Posts: 131	Re: 1966 C10 Ammeter reading I figured it out, reading a post on the Corvette Forum of all places. There was a post there that stated all electrical load up thru the 68 Corvettes ran through the horn relay via a wire from the solenoid to the relay. Looking back to my disassembly pictures, there was a wire from the positive battery cable to the horn relay. It looked like a bogus wire (non factory, non factory connectors) that was added when the prior owner added an aftermarket stereo. So I rigged up a test wire with a couple of connectors and ran it between the positive battery terminal and the hot terminal on the horn relay and...voila...ammeter now reading correctly.



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