95transamlt1

iTrader: (6)

I have a 98 trans am and my tach on my cluster went out but everything else on the cluster works. so we thought it was a short in the white wire from the pcm to the cluster but i took it to a reputable wiring shop and they tracked the wire down and its perfect . it just seems like the pcm is not sending the signal through that wire. but when you connect the scanmaster to the car it reads the rpms but for some reason the tach dont recongnize it. so i bought a monster tach and tried to connect it and it dont work either because the wire is not sending the signal. so what im wondering is if there is another way to connect the monter tach like to a coil or other wire so i can at least be able to read my rpms screw the tach on the cluster. so please help guys . post up your thoughts .

Eurospec2

iTrader: (2)

troubleshoot problem, if its PCM sell monster tach, buy new PCM, if its your dash, sell monster tack and buy another dash?

95transamlt1

iTrader: (6)

trouble shooted already and the cluster checks out perfect and so does the tach. so i dont wanna buy another pcm cause then i have to get it re tuned again. so im just looking for a way to get the monster tach to work screw the cluster . thanks

Eurospec2

iTrader: (2)

while i really doubt its the PCM, you woudnt have to have it tuned again if it is, just have your tune copied over. If everything else checks out good and it is the PCM id seriously think about replacing it soon anyways, if that part of the PCM somehow died then the rest may be soon to follow.

Eagle02

iTrader: (20)

You can also get tach signal from the coil packs, but it would be a bit of a hack job to not figure out why the dash tach isn't working.

Are you sure you've tapped the correct white wire for your external tach? Here's a link to a pic I took during my N2O install which shows the correct wire on the passenger fender.

I am unsure of the wiring to the cluster, but I don't think the white wire on the fender has anything to do with the wire that actually sends tach signal to the dash. Finally, its obvious the PCM still knows what RPM the engine is at if a scanner can still display it. Having some tuning experience, I'm also unaware of any way to disable the tach signal at the PCM... so either its a broken wire somewhere, or the connection between the bulk connector and the PCM output pin itself is failing for some reason...

OH OH, one last thing... you check the connections between the PCM and the bulk connectors yet? I had some very odd behavior when I got some water in between the PCM and those connections... Yeah, that was bad.

HTH,
-Eagle

95transamlt1

iTrader: (6)

can you give me directions to do it from the coil packs i just need a tach thanks .

Danger731

iTrader: (3)

I believe the PCM wire on a 98 and 02 are different. Any ways there is a wire also over the pass. side fenderwell at the 3 connectors there, forget the one. I'm not home now to look at the pics on file. Also a fyi, there are some PCM's with a 1/2 strength volatge signal, that could be the reason the tach isn't picking it up. Some were done that way to decrease noise. Anyways I can pm you later. also check LS1.com do a search there for tach wires, or under nitrous. I think there are the fenderwell pics posted there somewhere. Derek

95transamlt1

iTrader: (6)

anyone know how i can get my monster tach to work by taping into an ignition coil cause my white tach wire dont work . can someone give me step by step instructions on connecting it to a coil . thanks

95transamlt1

iTrader: (6)

help needed please

Danger731

iTrader: (3)

over the passenger fender there are 3 connectors. The middle one marked "G" is a tach signal.

95transamlt1

iTrader: (6)

i checked everything the pcm looks good all the connections are good and the white wire is in tach . i am starting to think that it may be the damn cam sensor how do i check if its the cam sensor and if the cam sensor went out would that cause no tach signal through the white wire?? please help

Eagle02

iTrader: (20)

If it was the cam sensor, you'd likely throw a SES light real fast...

I'll have to see about finding directions on tapping the coil pack for tach signal... dont recall how to do it off the top of my head.

-Eagle