I'm really pissed off at the moment, first i tried a NOS window switch my cousin had laying around free right but i wasn't sure if it worked. I wired it up and it wouldn't work. Now if i took the on pill out an put a jumper in there the system would work but if i put an RPM pill back in it, it wouldn't work.

So i go buy an MSD window switch, i found a few different ways to wire these things up on here so i tried another way AGAIN it would not work. And again it would work if i put a jumper in place of the on RPM pill. It's like it's not seeing the tach signal and i have the wire running to PIN 10 on the PCM. I cut that #10 wire just to see what would happen and the car started and all the gauges worked the only thing that didn't work was the TCS light came on is that right? If it's a tach signal shouldn't it affect the tach in the car?

Can someone throw me some help please i dunno what else to do, also i have an early 99 so i thought maybe the tach signal wire was where the 98's were......Nope there's no wire in pin 35 at all

 

Are you sure it was number 10? It should be a white wire. With it cut the tach should not work. Sounds like you got the wrong wire.

 

No i got the right wire it says 10 on it i know it's the right one

Here just to prove i have the right wire

 

https://ls1tech.com/forums/showthrea...+window+switch

And that's how i have the system wired before anyone says i have it wired wrong too

 

no one else can help

 

Figured it out from some research, i know you have to wire an aftermarket tach in an LS1 ignition as a 4 cyl. so i cut the red an blue wires on the switch so it was a 4 cyl. switch. That and the yellow wire from the window switch can only handle 1.5amp's apparently the FPSS puts out more then that and by some luck i bypassed it and it worked amazing i kinda feel smart now .

 

plz tell how u bypassed the yellow. i spent an entire day trying to get the tack signal to work. even pulled the relay off and wired everything direct. no go.
then stole the window switch of my daughter car thinking mine was shot...still no go...

 

I didn't bypass the yellow wire i just bypassed the FPSS. What kinda window switch are you using. I tried my cousin's NOS switch but there was no setting on it to make it for a 4 cyl. so it would have never worked.

Here's a diagram of how i wired mine since it wouldn't work the window switch connected directly to the FPSS.

 

thanks bro. gonna head out to buy another relay tomorrow...hopefully it will work...

 

I thought that was my problem too but it wasn't. Hopefully it'll work for ya, mine ended up being the switch wasn't set on 4 cylinder operation kinda stupid i have to do that.

 

yeah i've already clipped the wiring for 4cyl mode..
thanks again,
peace

 

why does it have to be on 4 cyl mode i hooked mine up and the tach worked just fine and i changed it from 8 cyl to 4 cyl. or does this not pertain to 99 ta just wondering i am going to finish installing every thing tonight

 

If its is an NX system you should not run the fpss in this manner. To many amps for that switch. THE FPSS can go on any low amp wire, split the YELLOW, windows black, or red, even the wot wires but not the solenoid wires. You could weld the contact together making that switch not work in the future.

old image but I think you get the idea.
Ricky