Autometer Gauges and Fuses

twfurst

Daily Driver
Apr 12, 2011
12
0
0
Norwich, CT
Question regarding fuses. In the Autometer instructions they "recommend" adding a 3A fuse (4A for Tach) inline on the power wire to each gauge. I am trying to determine what would be the correct fuse rating to use if I wire all the gauge power wires in parallel, and place the fuse before all of the gauges. I may be wrong, but I suspect it is not as simple as saying there are 6 gauges on this string, so (4x3) + (4x1) = 16 amps. If it is that simple, I suspect is would want to use a 15 amp fuse, not a 20 amp fuse. Any help is much appreciated.
 

LS6 Tommy

MalibuRacing Junkie
May 15, 2004
15,847
1
38
North Jersey
Ohms law for parallel circuits basically says the sum of the individual loads in the circuit, so if you have (4) 3A loads and (1) 4A load in parallel, you have a 16A total load for the circuit. Are they electric gauges, or is the circuit just for lighting? If they're electric gauges, I'd fuse each one separately. If it's just the lighting circuit, I'd use one fuse.

Tommy
 

twfurst

Daily Driver
Thread starter
Apr 12, 2011
12
0
0
Norwich, CT
I took basic electronics classes in the USMC about 15 years ago and couldn't recall the Ohms law principles. I'm talking about the gauges themselves, the lighting I will be tapping into the cars factory gauge lighting circuit. My reasoning for the desire to single fuse the set is
1. Accessibility. If I can run one fuse, that I can reach from down near the pedals, should something go wrong, I wouldn't need to rip apart the dash to swap a fuse.
2. When I am creating the harness, I would think it would be much cleaner and space saving to not have multiple fuse holders dangling around.

Thanks for the info.
 

twfurst

Daily Driver
Thread starter
Apr 12, 2011
12
0
0
Norwich, CT
Got all the fuse holders over the weekend, now to just get an uninterrupted afternoon to put together a harness.
 

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