Stereo & Electronics - Autometer Gauges

For anyone that has installed gauges, particularly Autometer gauges that have a red wire for the 12V connection, a white wire 12V to connect to dash and the black negative, have you either forgotten or purposely not added a 1 amp fuse to the red wire connections as recommended? I forgot to add the fuse on the red wire and the gauges were working with a temporary ground but after I hooked up the permanent ground they quit working. Is it possible in that short test run the 12V source damaged the gauges?

I have (5) AM Ultra-Lite Gages - never added an additional fuse to the power wire - don't even remember that being in the instructions.

They've all been working fine for 3 years now...

If the gage power wire is sliced into an existing 12v circuit that is already protected by a fuse, why would you need to add yet another?

The purpose of a fuse in most cases is to protect the wire that they are tied into from over current. Installing more than one fuse on a line does not regulate the amount of voltage that can pass thru the wire. Fuses do not act like 'valves' in a water system. The gages should operate on a voltage range (e.g. 12-14v or so) is your alternator putting out more voltage than the reccommended voltage range of the gages?

I've never added a fuse, I've run the wires through the fuse pannel so if something shorted out it would blow the fuse.

If the gage power wire is sliced into an existing 12v circuit that is already protected by a fuse, why would you need to add yet another?

I've never added a fuse, I've run the wires through the fuse pannel so if something shorted out it would blow the fuse.
You should add a fuse anytime you go from one gauge of wire to a smaller one - even if it's the third or fourth fuse in the line. One of the purposes of a fuse is to protect from an overcurrent condition heating a wire to the point of causing a fire. Obviously, a thicker gauge wire can carry more current without overheating than a smaller wire can. So, suppose you tap a 22-gauge wire into an existing circuit that uses 14-gauge wire. The original fuse was designed to protect that 14-gauge wire. It is quite possible to have an overcurrent condition that would overheat the 22-gauge wire and cause a fire without ever blowing the fuse in the original circuit. Fuses only cost a few cents - never, ever, ever connect a wire without making sure it is properly fused!


Fuses do not act like 'valves' in a water system. The gages should operate on a voltage range (e.g. 12-14v or so) is your alternator putting out more voltage than the reccommended voltage range of the gages?
This is true - fuses don't restrict elecrical flow like valves in a water system. However, it has nothing to do with voltage. You could run 50 volts through an automotive fuse without blowing it as long as the current never reached the point of melting the fuse filament. That said, the electrical system doesn't push current to the device (gauge, radio, amp, or whatever) - the device draws whatever current it needs. So the fuse would have nothing to do with any problem unless it blows. Even then, the fuse isn't the source of the problem...it's just reacting to a problem someplace else.

I got a small fuse block from autozone. It holds 6 ATO fuses, and has a central power hook up lug. A guy at autometer recommended that I put fuses on the gauges, so I took his advice. I spent a lot of money on gauges and I figured Ide protect them. I think I used 3amp fuses for each gauge.

It also made it easy for me just run one bigger gauge power wire to the fuse block, then just single wires down to each circuit.

Justin

:hijack:

So, I'm looking to install 2 Autometer gauges soon, so what would be the best way to wire it? Obviously the empty IGN slot on the fuse block, but would I just run two fused 18 gauge wires into that one slot? Or could I fuse each gauge, the run those together into one wire to go into the slot. Kinda like a Y.

You can do it like a 'Y' but you should use 16 gauge wire for the common section. The IGN port in the fuse box is protected by a 15 amp fuse so 18-gauge might be a little too small.

What I did was run 14-gauge wire from each of the IGN, ACCY, and BATT ports on the fuse panel to fuse/junction blocks in a more convenient location under the dash behind the console. That way, whenever I need to wire up an accessory I have power easily available and can put the appropriate fuse in the fuse/junction block. Those fuse blocks are just a couple of dollars at any auto parts store.