Hood/Heat Extractor lights

**robcas47** · 10-24-2010, 10:45 AM

Ok so I want to do the hood lights on my TA and since I've got the WS6 style hood with heat extractors I am wanting to route the lights to both front nostrils and to both heat extractors. I plan on using amber lights to give off the impression of a fire under the hood. What I am wanting to do is have the lights always on but at a dim setting and to progressively get brighter in sync with the rpm's and to dim as well. I am not sure but I think another member has done this before and so I'm wondering how it was pulled off. If not does anyone have any ideas? I was thinking of a window switch type setup but then there is probably a smarter way. I've asked this on both tech and a local Fbody board but didn't get as much help as I hoped. I know there's got to be an electrical guru out there that can figure this out.

**gotws6** · 10-24-2010, 03:41 PM

i have no idea. but thanks for your service! my son is in the army ft leonard wood.

**robcas47** · 10-25-2010, 08:30 AM

Originally Posted by gotws6

i have no idea. but thanks for your service! my son is in the army ft leonard wood.

No problemo, hope your son enjoys Army life as much as I do.

**robcas47** · 10-25-2010, 08:39 AM

Soooo any one got a suggestion/idea/refrence....
I tried the search too but the can only find the install sticky.

**ls1camino** · 10-28-2010, 03:55 AM

The one way I could think to do it would be to hook the power side of the lights to Throttle Position Sensor (TPS).

The computer uses that sensor to monitor how far open the throttle is, and I'm not sure what kind of damage would be done if you started tapping power from that wire.

**robcas47** · 10-28-2010, 04:53 AM

Originally Posted by ls1camino

hook the power side of the lights to Throttle Position Sensor (TPS).
I'm not sure what kind of damage would be done if you started tapping power from that wire.

This is what I was worried about. I initially thought I could easily splice into the wire that sends the signal to the RPM tach on the dash. But then I thought it might weaken the signal and give a false reading.

When you hook up and after market tach with shift light do you just rewire to go only to the tach or are you able to keep both working? If you can keep both without any issues then I may be able to go that route since the signal seems to increase/decrease in strength the way I want it to do with the lights.

**ls1camino** · 10-28-2010, 11:51 AM

Originally Posted by robcas47

This is what I was worried about. I initially thought I could easily splice into the wire that sends the signal to the RPM tach on the dash. But then I thought it might weaken the signal and give a false reading.

When you hook up and after market tach with shift light do you just rewire to go only to the tach or are you able to keep both working? If you can keep both without any issues then I may be able to go that route since the signal seems to increase/decrease in strength the way I want it to do with the lights.

When you wire up a tach, you tap into the signal wire that goes to one of the coil packs from the PCM. Then on the aftermarket tach, you tell it how many times per revolutions that coil fires. So for the LS1 engine, which has 8 coils for 8 cylinders, each coil pack fires 1 once every two revolutions, and the tach goes by that. The coil pack also has a separate 12V wire that is always hot and only fires the spark plug when the signal tells it to, so there is no interruption in the spark.

The TPS is different, it's going from the sensor TO the PCM, and requires a certain current to measure the opening of the throttle.

**robcas47** · 10-28-2010, 06:02 PM

Is the stock tach wired up the same way as an aftermarket? Will it work tapping into te signal wire or is it back to the drawing board?

**Smittro** · 10-28-2010, 09:11 PM

IMHO, what you need to maybe simplify things is a voltage regulating switch with a rotating contact.. LIKE the one used for the TPS rather than tapping the sensor wires. All you would then need to do is figure out a way to rotate it with the throttle. A ground wire could be ran down to the hood hindge. Just my oppy and a way I'd think of doing it.. You could possibly go to radioshack and ask them for a 12v varible voltage switch..

**robcas47** · 10-29-2010, 06:31 AM

That's a fresh idea, Thanks. I'll look into it, not sure how or what to hook it up to as far as a rotating component. There's plenty to choose from.

**nichoLaS1** · 11-16-2010, 04:31 AM

Somehow my Pioneer CD player in my jeep can read the RPMs and displays a fake tach on it..Unfort I don't know exactly where it is drawing the signal from, but if I can figure it out, I'll let you know.. doing something similar would prevent you from having to tap into any important wiring..

**robcas47** · 11-16-2010, 06:16 AM

G-Tech makes a perfomance meter that can read your tach just from pluging it into the lighter. Not sure how this is possible but they meake it work, I want one just for shits and giggles.

**KMdef9** · 11-17-2010, 07:16 AM

Originally Posted by nichoLaS1

Somehow my Pioneer CD player in my jeep can read the RPMs and displays a fake tach on it..Unfort I don't know exactly where it is drawing the signal from, but if I can figure it out, I'll let you know.. doing something similar would prevent you from having to tap into any important wiring..

Originally Posted by robcas47

G-Tech makes a perfomance meter that can read your tach just from pluging it into the lighter. Not sure how this is possible but they meake it work, I want one just for shits and giggles.

These horribly inaccurate readings are read from vibrations I believe.

This will probably be a difficult task no matter which way you approach it. Smittro's idea of attaching some sort of voltage restrictor onto the throttle body would be very interesting. The only hard part would be finding a resistance wiper that would somehow attach to it without interfering with the rest of the components. I'm sure it exsists, as there are millions of eletrical components out there. Also, that signal would have to be low voltage driven, unless you find components that are electrically guarded from everything, b/c the voltage source will be at the throttle body and this can propose obvious dangers. If it's low voltage driven, the signal would then have to be amplified to drive the lights, even if LED lights are used.

It would almost seem easiest to tap into the RPM signal, then amplify it to power the proper amount needed to drive the lights. No mechanical parts needed and should be the safest way to approach this. Just need to find a 12V signal amplifier for your application.

**robcas47** · 11-17-2010, 05:51 PM

Originally Posted by KMdef9

It would almost seem easiest to tap into the RPM signal, then amplify it to power the proper amount needed to drive the lights. No mechanical parts needed and should be the safest way to approach this. Just need to find a 12V signal amplifier for your application.

This was my initial appraoch to the idea but not sure if it will interfere with the correct readout of the RPM gauge. I'll look into to getting it done this way or might try sound activated leds and just stack them accordingly.

**KMdef9** · 11-17-2010, 08:50 PM

Originally Posted by robcas47

This was my initial appraoch to the idea but not sure if it will interfere with the correct readout of the RPM gauge. I'll look into to getting it done this way or might try sound activated leds and just stack them accordingly.

It shouldn't interfere with it, since you'll have to use an amp circuit to drive the lights, the the current draw should be minimal.

And...

When a new tach is hooked up to a car, it doesn't drag the stocker down. A new tach works with an amp circuit, so I'd imagine the stocker does as well. So, it shouldn't effect it.

If you try and hook up the lights directly to the tach line, it probably wont fire the LED's too well (unless your only hooking a few of them) and also may have an effect on the tach read out in the car.

**robcas47** · 11-18-2010, 09:18 AM

Ok thanks a lot KMdef9, I think I'll go that route and post results when I can get this done. Now I've got to read up on this amp circuit and find one that will work with what I've got planned.

**KMdef9** · 11-18-2010, 02:13 PM

Originally Posted by robcas47

Ok thanks a lot KMdef9, I think I'll go that route and post results when I can get this done. Now I've got to read up on this amp circuit and find one that will work with what I've got planned.

Not a problem. Please post the results and hope it turns it out well for you.

Also, radio shack is good for that kind of stuff and if you have any other further questions, let us know.