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Speedhut Gauges- And IGN Warning Lamp

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Jim_Gruber

Jim_Gruber

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Someone has been down this road before. I need some help,


Red Generator/Alternator IGN Warning Lamp LED on Speedhut Tachometer, Negative Ground Setup


So I was asked this question today and I don't know the answer. I asked for an IGN / Warning Lamp to be added on my Tachometer.


Purpose if Generator/Alternator fails, stops charging IGN Lamp glows Red


So does a IGN Lamp need to be Ground Activated or 12V Activated,


I realize that I need to have some sort of 12v Incandescent Bulb in there to Trigger the Alternator Charging On/Off Circuit but would I need a single wire / 3 wire Alternator?


And is it Ground Activated or 12V Activated. How do I set the Wiring up on this one.


Thanks Guys
 
Back to the top guys anyone got an answer to my question. I received this note in another forum: When using a three wire alternator the bulb Is powered by the white wire which I live when running. The other side of the bulb goes to the brown/yellow wire of the alternator. And I posed the following response. "So do I need a 12v or a Ground Activated Lamp. That becomes the question. I'll assume the lamp is not illuminated when in normal alternator working fine state. That setup would attach to a 12VDC Bulb which provides a load on the circuit and triggers charging. The LED cannot attach directly to the alternator as it does not draw enough load to trigger the Charging Circuit IIRC. So only wire coming off of the LED Lamp in the Tach would go to the Yellow/Brown wire and the other side to Ground. Or could I wire in parallel to the 12VDC Bulb. or take other other side of the LED directly to Ground." Can anyone help?
 
I'm using a single wire alternator on my Bugeye. But, if I was you I would contact SpeedHut and ask for one of their technical guys for advice!

However my Caterham has a three wire Alternator with LED bulbs in the gauges, their not SpeedHuts but the principals are the same. What I did was put a resister on the light wire in order to make the light go out when the alternator started charging. The resister is attached to the bottom of the aluminum bracket on the back of the alternator.

P1010256.jpg
 
As above, you need a resistor in parallel to the LED for an alternator installation. I cannot say what is required when a generator is installed.

The charge warning light gets 12V from the ignition switch when the key is in the run position. Current from the switch flows through the bulb and down to the windings in the alternator. The path to ground is through those windings. Current must flow through those windings for the alternator to start producing electricity. When the alternator starts making electricity, it brings the voltage "up" on the terminal where the warning light connects to the alternator. At that point, there is no voltage drop from the ignition switch to the alternator terminal so the warning light goes out.

The reason the LED will not work by itself is that the LED cannot allow enough current to flow through the alternator windings for it to start making electricity. Current must flow through those windings for the alternator to start charging. The resistor in parallel to the LED allows sufficient current to flow to start charging. Various resistor values will be found on the web. The last one I installed was something like a 10 Watt, 40 Ohm resistor.
 
Cool, sound like a Resistor in Parallel would be sufficient resistance to make it work. Sounds like I definitely need just a standard 12V Bulb in there not a Ground Start Setuup for the bulb. But I'll check with Speedhut guys.
 
nd a 1 wire or a 3 Wire Alternator would work just fine.
 
So here's Bugsy's Late Arriving Christmas Present. The Austin Healey Script came from MOSS Motors site BTW. Just a .jpg file that the Team at Speedhut was able to add for me. Little details, And sorry these are sideways, simply rotaye your Monitor 90 degrees and they will show up correctly. LOL.

View attachment 46938View attachment 46939
 
Those look really nice! Do post more pictures of them when the dash is done.
 
Pretty pleased with the way they turned out.
 
Dang Jim, I tried rotating the monitor but it knows it has been rotated and counter-rotates the image so still sideways. I finally had to lay down sideways on the desk to see the photos. A bit of a pain but they sure do look nice though.
 
LOL I wasn't about to open them back up and retake the pictures.
 
Dash comes after Front end and Rear end rebuilds and aligns with install of new wiring harness. Will reach a point however of how much I can get done before Drive time starts April, May. I don't want to miss another driving season this year. I want the 1,326 installed along with 5 speed but solving brake and steering and suspension issues comes before the engine install. If I get things back and drivable, the 948 w Cooper S Head and cam, and HS-2's is pretty fun to drive by itself. Engine work could get done when I pull things back apart for paint.
 
Jim, i should have an opportunity to get that aluminum for the spacers later this week. I should be able to get them into the mail early next week.
 
It's a Cooper Big Valve Head based upon Casting #. And since it sports a lumpy cam and a set of HS-2's and pulls like a train the assumption is that it has the larger Valves, same size as a stock 1275. This car was Auto-Crossed during its life and some work was put into this engine. Cam wise I do not know but it does have a bit of a lumpy idle. Doug, I do have a '67 1275 Hi Comp Head available that is currently a very heavy object in the corner of my basement that I keep accidentally kicking. I will not be using. I was intending to use it on my spare '69 1275, but that has now been replaced with a Rebuilt 1,326. Too many engines, one Sprite is enough to fill my one car garage.
 
Thanks Trevor, that will work. Front End Rebuild won't finish up until at least the 12th. A quick trip down to Marathon Key, FL for 5 days starts this Friday, back on Wednesday will provide a quick break from the cold. A carpe diem moment, from my sister , " Hey Jimmy, we've got this 4 BR House rented for a week...want to join us?"

In the meantime steering rack and tie Rod Ends are drying and Black Gloss Paint is getting hard in the corner of my basement.
 
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