08-03-2022, 01:49 PM | #1 |
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Location: Buckeye, AZ
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Wiring question
If you look at "A", what does that wire do? And what size fuse should it use? (mines missing)
Same for "B", what does it do and what size fuse should it use? (again, fuse missing) And last but not least, can I just connect wire A into the same place where wire B connects, inline from the alternator to the battery? This would help clean up the wire mess that I have. Thanks, Rob |
08-03-2022, 02:17 PM | #2 |
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Re: Wiring question
They are sensing wires for the AMP gauge. You could eliminate and convert to a volt meter to monitor your charging system
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08-03-2022, 02:39 PM | #3 |
20' Daredevil (Ret)
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Re: Wiring question
IIRC, the ammeter gauge takes 4amp fuses, about 5/8" long. They can be hard to find. I found some 5amp fuses at Napa, in a box with #782-1035 printed on it (maybe the wrong box?).
The fuses are stamped BUSS AGA-5A and the gauge is working just fine with them.
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- Mike - 1972 K20 LWB 350/350/205 RIP El Jay Last edited by Stocker; 08-03-2022 at 03:32 PM. Reason: added info |
08-03-2022, 02:43 PM | #4 |
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Re: Wiring question
Both wires lead to the ammeter located in the instrument cluster. The meter circuit is a shunt circuit so it's not actually an integral part of the charging circuit, just an indicator of charging/discharging function. This circuit is found only with the gauge and is absent with the charge idiot light.. Replace both fuses (3 - 4 amp each) and your ammeter should start working..
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08-03-2022, 03:09 PM | #5 |
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Re: Wiring question
Thanks guys, so I can probably wire them together and be ok.
Since they both come off the battery area, I wonder why there's 2 wires. |
08-03-2022, 03:13 PM | #6 |
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Re: Wiring question
The meter is a milli-vollt gauge not an amperage gauge like it is labeled.
Both side for the Amp gauge are positive. Don't wire them without a fuse. The circuit would not have any protection if you do. Cheers |
08-03-2022, 04:47 PM | #7 |
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Re: Wiring question
Your battery ammeter gauge will not work if you attach those two A and B wires to the same point. They must be attached to opposite ends of the red 12 gauge wire that connects the battery to the main splice where the alternator ties in. The gauge relies on the resistance of that long length (5-6 feet?) of the red wire to function correctly.
Last edited by pjmoreland; 08-03-2022 at 04:58 PM. |
08-03-2022, 06:06 PM | #8 |
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Location: North Texas
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Re: Wiring question
I just have to say that I'm happy to read the above responses. Over the years I have heard several folks (even one at a wiring harness company) say our trucks used a full current ammeter, and even argue the point!
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Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then! |
08-03-2022, 06:40 PM | #9 |
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Re: Wiring question
That would have surely blown the fuses and worse fried the harness
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08-03-2022, 09:53 PM | #10 | |
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Re: Wiring question
Quote:
Think of it like this. One point is closer to the battery, and the other to the alternator. The (as labelled) battery gauge reads the difference in the two voltages. If the alt is charging, the gauge will read charge because alt voltage is higher than battery voltage. To change the subject, not the fusible link in the diagram above and to the right of the battery. Make sure you have one, since without it a short can cause the harness to fry. |
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08-04-2022, 06:38 PM | #11 |
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Location: Kennewick, Wash.
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Re: Wiring question
I had my gauge cluster rebuilt and I had the Amp gauge replaced with a Volt meter. Everything seems to be working except the new Volt meter...any ideas?
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08-04-2022, 07:33 PM | #12 |
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Re: Wiring question
It's sort of bad form to hijack a thread, particularly when the subject is different.
A voltmeter would want one side 12V and the other grounded. |
08-05-2022, 05:28 PM | #13 |
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Re: Wiring question
You're fine man. Check out this thread: http://67-72chevytrucks.com/vboard/s...d.php?t=630289
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72 C10 lwb fleetside -stock 350/350 combo |
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