Ammeter hook up

[vintovka]

Down to fun stuff like details. One issue is hooking up the cluster ammeter. Its converted to 12 volt already and has worked well with a 60 amp alternator in the past. The shop replaced the fusible link with a circuit breaker and made some other changes like adding a relay for the push button starter (left over from its hydamatic days). Thinking of eliminating the relay (90 amp button and 10 gauge wiring). In addition considering wiring the ammeter on the other side of the circuit breaker. What do you think?

[Foot Stomper]

The circuit breaker is there to protect your entire harness and truck. Wiring the circuit breaker AFTER the the ammeter does nothing to protect the wiring to the ammeter which is always HOT.

I'm confused about why you are concerned about where the circuit breaker is in the first place since it's in the correct place now??

There's more to this story so fill us in.

[dsraven]

fuse or circuit breaker before load to protect the circuit
relay isn't a bad idea for a starter.
are you looking to eliminate the starter button and the related wiring and just go with an ignition switch style for starter actuation? a relay is still a good idea to protect the contacts in the ign switch. small guage wire (with a fuse or circuit breaker at the source of the power for the circuit) is usually used in the switching circuit to the relay. larger guage wire (gauged to provide ample power for the load you are running) is used, along with a circuit breaker or fuse at the power source, in the load circuit. so in short, the switch circuit has a small load, just enough to turn on the little relay, so it uses small guage wire. in the cab and dash area this is a bonus because the harness is much smaller and flexible then. this circuit runs up to switch on the relay which can be placed somewhere near the load (the starter in this case). the larger guage wire is run from the power source to the relay and from the relay to the load. this way the large guage wire has a shorter run so less voltage drop issue and better load performance.
if you look in newer vehicles the cab wiring is usually pretty small wire and then under the hood is a fuse and relay box with larger wire running to and from it. it will likely be near the battery as well. less large wire running all over the vehicle.
dunno if that helped but it sure is cramping my typing finger, lol.
let us know what you are trying to accomplish and we can possibly help.

when I say larger guage wire it is actually a smaller number in the guage chart. a 22 ga wire is much smaller than a 10 guage wire.

[vintovka]

I'm an old timer and both stater relays and circuit breakers are new to me. A relay in the starter circuit seems redundant and a possible weak spot as Its power source is fused. It does work ok so may leave it alone.

I would like to wire in the cluster ammeter in the easiest way. Most diagrams show wiring it in just after the circuit breaker.

I'm so old i was shocked when i was discussing this issue with a young local gearhead and mentioned how i didn't miss generators. He looked straight at me and asked "whats a generator". I felt like an antique.

[_Ogre]

the original ammeter is 30 amps, most of us are running 60 to 100 amp alternators
while the ammeter may work for a while, why risk possible overload or fire in your project?
it can be rewired, but it also requires all power to the panel rerouted thru the ammeter

an ammeter has limited use in a vehicle and has been replaced by the volt meter
i converted my ammeter to a volt meter and did a write up in my thread and a separate thread

this is a mopar diagram but similar to any ammeter wiring

[1project2many]

A relay in the starter circuit seems redundant and a possible weak spot as Its power source is fused.

There are some benefits. As the starter solenoid ages it can require more current to engage the starter. Remember when starter "rebuild" kits came in 10 and 20 oz. weights with hammer handles attached? A separate relay can help. Also, reproduction ignition switches and buttons aren't necessarily good quality so reducing the current flowing through one can extend component life.

Although they seem like weak spots, many of the electrical connectors today are much better than the old ones for long life. 200K plus miles and two starters on my 2007 shop truck and the starter solenoid fuse is still intact.

[dsraven]

like ogre mentions, if you have a newer style engine and alternator then the original amp guage may not cut it. I don't think I have seen an alternator with that low of an output rating. on the other hand, a volt meter is nice to have because the alternator will charge up to a certain rating and keep the voltage fairly consistent the whole time. once the alt has met capacity then the voltage will start to drop. that is one way of checking an alternator output. a load is applied and the current output and voltage are watched and compared to spec.
long story short, if you have a 30 amp meter and you have enough stuff connected to draw more than 30 amps, or the capability to charge more than 30 amps, then the meter will not last and may cause a small fire in extreme cases. it would suck to do all that work and then fry the cab due to a missed step.
circuit breakers can be auto reset style so they will blow under load, then reset when they cool off. no fuse to replace that way. no dash to crawl up under, no skin to lose off the top of your head while trying to find the fuse box.
fuses and circuit breakers are there to protect you circuits and ultimately your investment. a short in a trailer plug, for instance, could fry the whole wiring harness from the battery back and may catch the truck on fire.
just a couple of thoughts to consider

[vintovka]

Thanks all. I think i will leave the starter relay the way it is and abandon the idea of using the cluster ammeter altogether. I already have a voltmeter is the aftermarket 6 gauge array and a 60-60 ammeter too. I will use Ogres diagram to wire the ammeter up. As an old flyer i like the idea of having duplicate/redundant instrumentation whenever possible. With the exception of the oil pressure gauge the cluster is for looks only at this point anyway. If i win the lottery i will get an all new cluster.

I should add that I'm using the original fuse block from the 84 GMC chassis and separate relays for each of the items drawing amps like heater, wipers, boat horn, electric fuel pump etc.