Flashy71RR
New Member
Seems to be no power at the 5 amp fuse under dash ... fuel guage quit and the cluster lights started working after years of being out?? Could use some info or advice.
Fuel Gauge Problem
- Thread starter Flashy71RR
- Start date
what car?...what year....need some info
Flashy71RR
New Member
Sorry I didn't put enough info.... 71 Road Runner .. 383.. auto ... under dash wiring is a scary mess.... have scematics, but cant seem to find what powers the 5 amp instrument fuse?...
440roadrunner
Well-Known Member
The inst fuse is only for "instrument lamps" IE the cluster and radio lamps, etc that are controlled by the dash dimmer control. It is the only fuse on old Mopars that will have NO power until the light switch is turned to either park or head.
The dimmer gets power from the tail fuse at the headlight switch, goes through the dash dimmer, and then (tan) to the fuse. The output of the fuse (orange) feeds all your dash lights
Now to your problem.....There IS NO fuse on the "stuff" powered by the ignition switch by what is known as "IGN 1" or "ignition run." Traditionally dark blue, the wire is hot only with the key in run
It feeds power to the cluster guages and warning lights (oil, brake, etc) and out through the bulkhead connector to power
ignition
regulator power
On 70 / later cars
also feeds alternator field (blue)
electric choke if used
throttle idle solenoid if used
dist. retard solenoid if used
some other smog doo dads on some cars
What gauges do you have, and what does not work?
The temp, fuel, oil if you have it are fed power from the dark blue THROUGH the instrument voltage limiter
There are several things that can cause your gauge problem, depending on what does and does not work.
Bad connections at the cluster harness connector
bad instrument regulator
bad connections at the regulator socket
bad connections at the gauges
bad connections in the sender wiring, IE
temp and oil go through the bulkhead connector,
fuel gauge goes through the rear harness connector in the kick panel.
The dimmer gets power from the tail fuse at the headlight switch, goes through the dash dimmer, and then (tan) to the fuse. The output of the fuse (orange) feeds all your dash lights
Now to your problem.....There IS NO fuse on the "stuff" powered by the ignition switch by what is known as "IGN 1" or "ignition run." Traditionally dark blue, the wire is hot only with the key in run
It feeds power to the cluster guages and warning lights (oil, brake, etc) and out through the bulkhead connector to power
ignition
regulator power
On 70 / later cars
also feeds alternator field (blue)
electric choke if used
throttle idle solenoid if used
dist. retard solenoid if used
some other smog doo dads on some cars
What gauges do you have, and what does not work?
The temp, fuel, oil if you have it are fed power from the dark blue THROUGH the instrument voltage limiter
There are several things that can cause your gauge problem, depending on what does and does not work.
Bad connections at the cluster harness connector
bad instrument regulator
bad connections at the regulator socket
bad connections at the gauges
bad connections in the sender wiring, IE
temp and oil go through the bulkhead connector,
fuel gauge goes through the rear harness connector in the kick panel.
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