55.2-59 What is this red light?

[RostaRob]

This used to be mounted on the steering column. Can anyone definitively tell me what it is? Can I disconnect it by tracing the wires back and removing with no harm or issues coming up? This is a 1958 Apache. Thanks. Rob.

[dsraven]

that is a light used for identifying an accy circuit usually. like fog lights,engine cooling fan or anything like that. if you trace the wires back to the source you will find what the circuit was and if it is still relevant. some guys will also connect them to a gauge switch, like an idiot light, so if the unit has, say, an aftermarket gauge cluster that reads actual oil pressure or engine temp but no visual indicator in the dash, a secondary low oil pressure switch or high engine temp switch would be wired to that light. that way if you are cruising and not watching the gauges the light would draw your attention and alert you to check the gauges.

[mr48chev]

Can't add a cotton picking thing to what Dsraven said above, he nailed it.

If you haven't done so follow the wires and see where they go.

[1project2many]

DSRaven managed to nail almost every circuit in the truck. lol. The only other thing I'd be interested in monitoring is the park brake. The location the light is installed is actually a notch for a column mounted shifter rod to pass through. There was never a factory light installed in that location.

Do you have a red push/pull switch on the shifter? Maybe the light indicates the electric supercharger is engaged like Mad Max?



(Small side note: I have a '79 Monte with Buick 455 and switch pitch THM400 which I built in my teens. I used a floor mounted dimmer to switch between low stall and high stall converter modes. In order to indicate the "switch pitch" converter was in high stall, I connected the "fasten seat belts" light to the output of the switch. It seemed cool at the time... lol.)

[57tailgater]

Yup - not stock as that's where the OEM column shifter rod goes through. You'll have to follow the wire(s) to see where they go.

[58CameoAZ]

That Light goes On when you are driving threw a Red Light District. :/ Lol.....

[mr48chev]

I just want to know where the other ends of the wire went now.

[1project2many]

Originally Posted by 58CameoAZ

That Light goes On when you are driving threw a Red Light District. :/ Lol.....

As if there's nothing in the scenery to alert you to it?

[RostaRob]

Ok here's what I found. There were two wires going to this light. One went to the acc post on my ignition switch and the other went all the way back to this plug on my alternator. So now I'm even more confused. Can I remove it with no harm? The wire in question is the brown one. Any info would be much appreciated. Rob.

[dsraven]

that is the "charge light" indicator wire. the old trucks didn't have that indicator, they had an amp gauge. some guys will install that light as the indicator usually found in the dash. the old "idiot light". it will be illuminated when the key is turned on, then shut off when the engine starts and the alternator is charging. on some alternators the engine will need to be revved up off idle to "excite" the alternator into charging mode to get the light to stop lighting up. basically there is power fed through the bulb to the alternator, which acts as the ground for the bulb. then when the alternator starts charging that wire is also powered positive so the build gets power from both sides and stops lighting up..

[RostaRob]

I have noticed that the light would go away if I revved the engine so I was leaning towards some kind of oil pressure light before I traced the wire down. Do you think I can just unplug that from the alternator and get rid of it with no issues?

[1project2many]

You can unplug it from the alternator with "sort of" no issues. That light provides power to the stator to excite the alternator. Without power from the light the engine will need to be revved up kind of high to start the alternator charging. You will also have dim lights until the alternator charges when they'll get very bright. Once the alternator starts charging you're good until the next trip, but it's still annoying for some people.

I installed a diode that allowed power from the key to the alternator but blocked power from the alternator backward to the ignition. This way the alternator charges early but my electronic ignition doesn't think the key is still "on" because the alternator is powering it up.

[dsraven]

https://smithcoelectric.com/blogs/te...wiring-diagram

[dsraven]

http://www.oldengine.org/unfaq/10si.htm

[mr48chev]

That light works in place of the diode that 1project2many mentioned. I'd leave it as is because it works and when it goes out you know that the alternator is charging. It does a job and you don't have to feed it or carry water to it so life is great.

[dsraven]

with all that said, you don't need to use that particular light in that particular location. you could opt for a smaller light mounted in a better location as you wish. it just needs to be a bulb wired in the circuit or a resistor wired in the circuit.