please help with rpm window switch

boosttoy

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Hi guys i have a msd window switch that a has been modified for my 97 gts.I can not get it to work.Could some one tell me how to wire it on my car?Please give me wire colors and or ecu specific wires to hook to on a 97 gts.I have a factory service manual if this will help.Thanks in advance.
Frank Ward
 

HP

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For a tach signal - you need to access one of the coil wires -
check out illustrated upgrades - shift light install.
 

Jack B

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The shift light uses the tach leads. These can be picked up at terminal block C1 (below PCM) or at the tach terminals in the dash. Almost impossible with a Gen II.

The window switch utilizes any coil pack drivers picked up at C3. They cannot be interchanged.


SHIFT lIGHT PICK UP
96Shift_Light_Connection_3LR-med.jpg



WINDOW SWITCH PICKUP
96Window_Switch_Connection_at_C3LR.jpg
 

HP

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Jack - I can see that you haven't reviewed the shift light install
in the illustrated upgrade section. You must have the only shift light made
to access the tach signal - most won't work off it.
Anyway - the picture in the upgrade section uses the A-1 wire YL/GR(coil driver
#4) - you're using A-3 (coil driver #3) for your window switch.
Any coil driver(there are 5) will work for most shift light AND window switches.
The tach signal - for most purposes, is useless(obviously there are exceptions).
Theoretically any electronic output that gives off a pulse proportional to
actual RPM could be used for both - it just depends on the options available for your shift light, or Window switch.
 

Jack B

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HP:

I did not look at the the install directions, however, I have done this on both a Gen 1 and Gen 2. I have both an Autometer shift lite and window switch. The shift lite does work off of the tach pulse and the Autometer direction direct you to that pickup. The window switch does not work off of the tach pulse, I mistakenly tried that. The directions for the window switch are to use the any one of the coil pack drivers, not the output. A pulse is not a pulse, gate width and magnitude must be considered. What is perceptible to one device might not actuate another device.
 

HP

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For any add on part that requires a RPM signal - the manufacturer will give
you the options for input signals. Any of the 5 coil trigger wires(grounding
wires controlled by the PCM) will give you 2 pulses per RPM - so you have to
take that in consideration. Dual firing coils are not that common, and
the reading, as compared to a single firing coil, will be double of the actual
RPM. Just follow the instructions supplied with the part, there are various
options to allow for different signals. Unfortunately there are some performance ignition related parts that will not integrate with the Viper -
so do your homework first.

To limit your search, check on the brand and type of RPM switch that
someone else(ie Jack) has had success with, and copy their setup.
Options could vary, from brand to brand.
 
OP
OP
B

boosttoy

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Ok guys the install instructions are very vague.On old style single coil inductive ignition systems it says to hook the rpm input wire to the negitive side of the coil.On cdi ignition it says to hook the rpm input wire to the tach output on the multple spark discharge box.There are no instructions on multiple coil distrbutorless ignition system vehicles.I hope this helps you guys to help me.Thanks very much for trying so far.Someone who has hooked up a msd window switch before please help.
Thank again,Frank
 

MES

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There are 3 connector plugs on the PCM Remove the one closest to the front of the car, find the red wire with a yellow stripe. Tap into this wire (do not cut it) attach to the white wire on the RPM window switch. Once you get this working you most likely will need a MSD relay as the RPM switch can't handle the current needed to turn on/off your nitrous system. Use MSD part number 8901 single pole 30 amp relay. Wire it in series with your main on/off toggle switch.
 

Larry Macedo

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The tach signal can be picked up at the PCM, but you will need to make sure MSD calibrated your window switch for 2.5 pulses or it won't work even if it's correctly installed. The usual scenario is you purchase the window switch, then it must be sent to MSD for calibration in order to function on the V10. Make sure you specify Viper V10 or they will send it back calibrated for a Triton V10, which is 5 pulses... Already been down that road with MSD.
 

Jack B

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Joe:

for your info, the shift light comes off of the tach signal. The MSD window switch comes off of the coil pack drivers. It is so simple I have the colors, numbers, terminal location and wiring diagrams for both in "My Gallery", someone wake up the point-to-point diagrams are posted.
 

Joseph Dell

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The pic up above worked just fine. Grey with the light blue stipe. Port #30, methinks. Tapped it in and it worked just fine!

Now, if only I could find a switched power source that does NOT go off when the car is switched from ON to START... next project is finding the "correct" power source for the autometer electric boost gauge...

JD
 

J DAWG

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I have the new MSD digital window switch and tapped into pin #31 on C3(grey) and now the tach doesn't work and neither does my LM1 tach signal. The pic above is now a red x.



Where should I put the white wire?


John
 

J DAWG

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Jack I guess the grey is considered C1. C3 must be the black one on the pcm toward the front of the car.


Anyhow I attached the white wire to pin#3 (red/yl) on the black one(C3?) and all is well. Still have my LM1 reading off the tach signal(pin #31) and works fine.


I am using the new MSD digital rpm window switch. No need to send it to MSD, one just chooses what rpm to turn on the spray and then what rpm to turn it off. Goes in 100 rpm incriments(sp). Then choose the cylinder type and it is done. I could have used the vec, but I am not sure if I will continue using the vec.



John



ps - sent you a pm Jack.
 
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