1972 Fuse Box Decisions

[Dibbons]

I need to add an old school Sun tachometer and a new school air/fuel gauge to the '72 Satellite Sebring Plus (no a/c). The air/fuel gauge calls for connection to a circuit with a 10 amp fuse. The tach instructions don't specify.

So I have little brass tabs I purchased so I can connect the positive wire on the gauges to one or two of the glass fuses. I only see 20 amp and 5 amp in the factory labeled fuse box, so not sure what to do there with the air/fuel gauge that calls for the 10 amp protection. I guess the tach can go on a twenty for now.

I would like to know without testing all day long if one or more of the 8 fuses locations are not even being used for anything at the moment (i.e. "misc" left bottom slot, or "acc" right second from top slot) Does anyone know about how this was set up from the factory? Thank you

 

[pnora]

I need to add an old school Sun tachometer and a new school air/fuel gauge to the '72 Satellite Sebring Plus (no a/c). The air/fuel gauge calls for connection to a circuit with a 10 amp fuse. The tach instructions don't specify.

So I have little brass tabs I purchased so I can connect the positive wire on the gauges to one or two of the glass fuses. I only see 20 amp and 5 amp in the factory labeled fuse box, so not sure what to do there with the air/fuel gauge that calls for the 10 amp protection. I guess the tach can go on a twenty for now.

I would like to know without testing all day long if one or more of the 8 fuses locations are not even being used for anything at the moment (i.e. "misc" left bottom slot, or "acc" right second from top slot) Does anyone know about how this was set up from the factory? Thank you

View attachment 1972255

View attachment 1972258

Put the tap on the hot side of the fuse and install an inline fuse of the correct amperage for each item you add.

 

[Dibbons]

For future reference:
The 20A horn, 20A hazard, and 20A misc are hot all the time.
All of the others are switched on with ignition except for "instruments" which is switched on with parking/headlamps.

 

[Bird 426]

The A/F probably has a heater in it.

 

[Nacho-RT74]

You have an already fused source from accesories 20 amps fuse on a triple bullet female feed. Tan wire yellow mold close to the steering wheel column area (Circled in red on pic). Just get the power from there. Need a bullet terminal of course.

This feed mold is coming out from main harness tape, hanging around.

(71/72 gets in fact two of these molds where 73/74 gets just one… this is because Chargers got hidden headlights as option and needed more sources)

Use one of those molds and call it as a success. Don’t need to reinvent the wheel.

On pic you can see the red mold on pink wire which is around center speaker area, for batt source (also fused), orange mold, for gauge lighting (dimmered) located close to the A/C-Heater control area. Use that for the gauge light. Door ground jam switch source ( black mold yellow wire) around glove box area if my memory serves good. This one is barelly used for added accesories but used for the map light, ignition key courtesy light… and some other similar accesory but tipically factory ones.

The fuse box inserted terminals rarely are needed to be used. They are a straight buss bar sources.

On a side note, left side 5 amps fuse is for the RUN circuit dash functions. Seatbelt warning system uses that source, same as the brake light warning light on cluster, and JUST ON STANDARD CLUSTERS the voltage limiter serves from that source. On Rallye cluster, voltage limiter uses ACC circuit, not RUN. 71s don’t have this fuse but an empty cavity. Not even terminals for fuse there.

Power window relay is also triggered to activate the full circuit from the RUN circuit

The other 5 amps fuse (right side) is just for dimmered lighting system (orange circuit).

Both are divorced from buss bars.

All the rest are all 20 amps and linked to buss bars (either BATT or ACC).

The fuses located over the BATT terminal embossed into the fuse box are of course linked to the BATT buss bar, and so on the ACC side