1G Anybody know how to wire up MSD 8969 window switch

[ist dwa]

I have a DIS 2 with the tach wire mode to eliminate the need for a tach adapter. Disclaimer I bought the 8969 window switch used on EBAY. The system powered up and I can adjust it, I had it set to 2 cyl waste spark. Other weird thing was the unit powered up before I installed the ground wire for the 8969.

I tried attaching the 8969 white wire to the tach output on the MSD dis 2 (part of the tach wire mode pictured below) , but it didn't work.....well it did read but it read exactly double real RPMs which won't work. I then switched the 8969 white wire to the negative side of the coil brwn/whte wire at the MSD unit, and same result read double. I then on the 8969 cycled through the settings of available types of cylinders and then it killed the car and read 0, at that point I disconnected the damn thing as not wanting to mess anything up, after disconnection the car runs and drives normal as before. I have given up, did I do it wrong, do I need a tach adapter, or is the unit junk. The company MSD was randomly closed for no reason Friday when I called so no help there.

Help would be appreciated.

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[brads]

I have a DIS 2 with the tach wire mode to eliminate the need for a tach adapter. Disclaimer I bought the 8969 window switch used on EBAY. The system powered up and I can adjust it, I had it set to 2 cyl waste spark. Other weird thing was the unit powered up before I installed the ground wire for the 8969.

I tried attaching the 8969 white wire to the tach output on the MSD dis 2 (part of the tach wire mode pictured below) , but it didn't work.....well it did read but it read exactly double real RPMs which won't work. I then switched the 8969 white wire to the negative side of the coil brwn/whte wire at the MSD unit, and same result read double.

Change the settings on the window switch to 4 cyl, and hook the window switch to the white wire output from the MSD. Their instructions could use some clarification, but that would get you a correct number of pulses, and fix that issue with it reading double.

You may have killed the window switch when you hooked it to the coil output from the DIS-2. The instructions for the window switch say to use the TACH OUTPUT from a CD Ignition, or you can hook to coil negative on inductive ignitions. The CD Ignition puts out a pulse that is likely to damage a circuit that is designed to read a 12V wire or standard ignition coil signal.

I then on the 8969 cycled through the settings of available types of cylinders and then it killed the car and read 0, at that point I disconnected the damn thing as not wanting to mess anything up, after disconnection the car runs and drives normal as before. I have given up, did I do it wrong, do I need a tach adapter, or is the unit junk. The company MSD was randomly closed for no reason Friday when I called so no help there.

Help would be appreciated.

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[ist dwa]

For the record and I didn't say so in the op....and I knew I should have. On the original hook up when I was on the tach output from the MSD I did change it to 4 cyl, because exactly your thinking, 2 to 4 should drop the reading....it didn't work.

I really feel a tach adapter may be necessary for this to work but I have probably fried the thing now, I had a feeling it may be used junk anyways, so I went for random wiring guessing. I did not find any instances on the web for double the reading problems. Only MSD could take something so simple to wire and not give explicit wiring instructions. Web searches showed this thing is a nightmare to wire for 4 cylinder engines. Did I research it before? No...because it is a window switch, should be simple, guess not.

 

[brads]

Did you turn off the power to the window switch after adjusting that cylinder setting? Some ignitions/devices will only read those values at power on. It affects all the other calculations the device does, and shouldn't be changed after it is installed.

Edit: to clarify what I meant about "shouldn't be changed" is that people will rarely change it after install, so that is a reason why it doesn't need to be constantly read, and only read at power on.

 

[ist dwa]

Dude, you nailed it. I had it wired right but you do have to turn the 8969 off to make a settings change (does the instructions say that? NOPE). After I read your post I went out and reconnected the white signal wire from the MSD 8969 to the tach output of the DIS 2 how I originally had wired it, changed the settings on the 8969 to 4 cyl, then turned the unit off, then started the car and it reads exact, thanks so much, I was really dissapointed, now I have to go see if it actually turns stuff on and off when it says, thanks a bunch, you really helped me out!!!!!!!

 

[brads]

Glad to hear it is working now.

I really didn't expect it to still work after it was hooked up to the CDI coil output.