tach gauge

[joe0508]

I hooked up a tach to my 454 big block last night and the strangest thing happened.I hooked every wire correctly only thing i didnt hook up was the tach signal.I figured i would get at least some light to alluminate from the gauge for a test that i was getting power.When i started the engine the mph gauge started to climb and i started to smell the gauge.When i went to shut the engine down it wouldnt stop running even after i turned the key off.Finnally after about four or five seconds it shut off.The gauge never lit up but i could smell it.Smelled like i fried it.Cant figure out what went wrong or what made the engine act like this.After trying to hook the tach up and failing i temped to wire my vacuum gauge,I wired it up the same as i did the tach and it alluminted lite and is working.I am still confused what went wrong with the tach gauge.

[joe0508]

2500HDee wrote:
Did you accidentally connect the power for the light to the signal wire, and the signal wire to the power wire on the distributor?

No,Actually i left the green wire unhooked and only hooked the constant power,switched power and ground.I was just testing the gauge to see if it would light up before hooking the signal to it.

[joe0508]

LittleBill wrote:
actually sounds like he somehow back fed the ignition system through the gauge and it keep the engine running till the high amperage burnt out the gauge and killed the back feed and killed the ignition

You think it was where i hooked the wire for the switched current to the alternator fuse?Because when i hooked my vacuum gauge up i hooked it to the radio fuse and it works fine.

[2500HDee]

Did you accidentally connect the power for the light to the signal wire, and the signal wire to the power wire on the distributor?

[LittleBill]

actually sounds like he somehow back fed the ignition system through the gauge and it keep the engine running till the high amperage burnt out the gauge and killed the back feed and killed the ignition

[tvman44]

Probably a defective gauge. 😞

[joe0508]

joe0508 wrote:
I hooked up a tach to my 454 big block last night and the strangest thing happened.I hooked every wire correctly only thing i didnt hook up was the tach signal.I figured i would get at least some light to alluminate from the gauge for a test that i was getting power.When i started the engine the mph gauge started to climb and i started to smell the gauge.When i went to shut the engine down it wouldnt stop running even after i turned the key off.Finnally after about four or five seconds it shut off.The gauge never lit up but i could smell it.Smelled like i fried it.Cant figure out what went wrong or what made the engine act like this.After trying to hook the tach up and failing i temped to wire my vacuum gauge,I wired it up the same as i did the tach and it alluminted lite and is working.I am still confused what went wrong with the tach gauge.

I also hooked the wire for the switched power to the alternator fuse.Could this have something to do with the issue?