I hatched an idea that is starting to give me grief. I would like to make a circuit to light up some bulbs or LEDs to show which gear my newly installed 4T60E has selected. I'm only interested in showing P-R-N-and D. My trans range switch sends a combination of grounded wires to the PCM for each gear. I want to tap into these wires to light up the bulbs/LEDs. Seems like a combination of AND + NOT gates will fit the bill. I googled logic gates but all the sites just give me the truth tables (which I understand) Guess what I'm looking for is some actual hardware specs. My understanding is that when I have the 2 inputs to the AND gate go low and then run the output of that gate to a NOT gate I will get an output to light my "fire". I believe that I have the theory down but not the practical specs to build the stupid thing.
HELP

do you have any info about the electronic access to this other transmission or car your talking about?

I assume you have the normal slotted gate for the auto shifter. Why not just black that out where it reads R N D 1 2. Then mount a single lite or led under that with a single hole drilled into the blacked out indicator. The indicator or a plate under it moves when you move the shifter (at least on some cars, dont know about Fiero for sure) so that light will glow thru the hole for whatever gear your in.

I'm trying to do away with the stock plastic shifter surround -no gear indicator on the surround

You would have to run the output of the gate to the base of a transistor to power the LED. The gate can not handle the current needed to light a standard LED. You can use the AND gate or simplify things and use a Hex Invertor like a 7404. It just inverts the binary signal. Good luck, that should be easy to do. You could also use different color LED's for different gears, like green for drive, red for reverse, etc..

Ive seen those in some newer cars ive worked on. Cant remember what makes, but scrounging a junkyard may find you all the parts needed. Seems like one was Honda.

quote Originally posted by rogergarrison: Ive seen those in some newer cars ive worked on. Cant remember what makes, but scrounging a junkyard may find you all the parts needed. Seems like one was Honda.

As far as I can find the cars that have the PRNDL lights ,the lights are controlled by the PCM - I'm still running OBD1 which doesn't seem to have that capacity.

Damn... About 3 years ago I built this circuit. I even ordered about 100 circuit boards to make them. I'll have to look and see if I still have the chip program on the computer. The (1) demo that I built I just had lighting an LED for each gear, but it could also be connected to a 7-segment LED to show "L" / "P" / "R" / etc.. I saw the circuit boards the other day while looking for something else.. I'll be home in a couple days, if you want to shoot me an email as a reminder I'll try and look for the stuff when I get home. (at the GF's relatives now, killing time in O/T...) I used an Atmel microcontroller instead of discrete gates. It was for my 4T65E but likely has the same input combinations.. < r i c e b u r n e r 9 8 @ c o m c a s t . n e t >

Riceburner, I am also interested in this. I just put a 4t65e in a originally manual fiero and built my own shifter surround with no gear indicator. would love some led's on the inst. panel telling me what gear im in. Would really like one that tells me what gear is selected and what gear trans is actually in so when OD is selected it will tell you 1st 2nd 3rd as it shifts.

quote Originally posted by Mike Gonzalez:Would really like one that tells me what gear is selected and what gear trans is actually in so when OD is selected it will tell you 1st 2nd 3rd as it shifts.

I've heard of someone doing that, but have no idea how you'd hook it up. I only looked into it as far as accessing the lines coming out of the PRNDL switch going to the ECM. Where would you get the signals of what gear the trans is actually in? I don't have any of my manuals at home.. Either of you guys have a scan of the "truth table" in the manual for the PRNDL switch? Would be nice to test out the circuit to see if it works before possibly sending one to someone. Even if I had easy access to the car (50ish miles away), I have a Getrag in there now.. Maybe I should just drive down and visit Phil. I've been there at least once already. How'd that truck in the garage come out?

Riceburner
Sent you an email with the truth table

quote Originally posted by Mike Gonzalez: Riceburner, I am also interested in this. I just put a 4t65e in a originally manual fiero and built my own shifter surround with no gear indicator. would love some led's on the inst. panel telling me what gear im in. Would really like one that tells me what gear is selected and what gear trans is actually in so when OD is selected it will tell you 1st 2nd 3rd as it shifts.

How about the main cluster where the 'mystery' cut out exists?

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Ol' Paint, 88 Base coupe auto.
Turning white on top, like owner.
Leaks a little, like owner.
Doesn't smoke....... OK, we're trying to quit.

What is the Mystery Cut Out ? Has anyone figued out gear indicator LEDs yet ? Would it be possible to tie in to the gear selection pins on the PCM of the L67 to feed the ground for the appropriate led ?

Haven't been checking back here in a while.. I sent out the circuit for Phil, I believe he's got it installed now.. I'll let him share any impressions about it. I think it came out pretty well, but the only instrument cluster I have right now is sitting on my desk.. Hopefully it works as well in the car. It taps into the Trans wires from the switch that go back to the PCM.

The "Mystery cutout" above the tachometer is an unknown.. The metal panel isn't cut out for anything, but under the metal panel there is an area with 2 light bulbs (not installed) in the cluster. They're "sort of" there on the circuit behind the cluster as well. (one has the pads for the bulb, the other is cut off) The one with the pads goes to a contact on the wiring harness plug, the other goes to a contact on the plug and a not-installed contact that would go to the tachometer board... Maybe one was supposed to be a red-line indicator? Or some other function that was planned for the tach but never built? Who knows.....

[This message has been edited by Riceburner98 (edited 02-01-2009).]

Well I got it installed and it works GREAT. I now have PRND321 lights in the mystery window above the tach. I haven't taken any pics yet because I had to change out my fuel pump and it was cold out in the driveway. Today was the first time driving the car. Doesn't affect the electronic shifting of my 4T60E at all. Now the wife just has to finish up my shift boot and all will be done.

Tho im late, these guys has tiny and cheap SBC's that are just perfect for stuff like this:

http://www.modtronix.com/

Some even have a CAN bus, could interface direct to the ECM that way.

Cool boards there, thanks for the link! A bit overkill for only the PRNDL job, but could think of lots of fun stuff to do with those.