AEM 6100 LQ9 Tach | AEM
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Raysupra
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Joined: 08/24/2014 - 12:03
AEM 6100 LQ9 Tach

AEM 6100 box: 3.2v  02V02

Hello,  I'm in a older car 1985 mkii, the gauge cluster was modified to receive a 7m 12v square wave signal IIRC.

So Its esentially a 1988.5-1992 mkiii Supra cluster that would receive a 7mge 7mgte Ignitor Signal.

 

5M/7MGE = direct coil voltage
7MGTE = 12V wave
Most JZ and standalones = 5V wave (but may require pull-up or pull-down)

 

I am Running a 2jzge Distributor on LQ9 coils.    so 16A and 38A Are both TACH outputs? 

I'm trying to figure out what is the difference between these two pins and what the Output signal is?

5v Wave?

currently I am on 16A switch LS7 on Stock Tach output.  and Did not get any rpm

Does this just mean I am receiving a 5v wave signal to my cluster that requires a 12v Wave?

Anyway to get a tach signal to my cluster?

 

I also Have NO Fuel Pump ECU, so I cannot use Pin 22A to control a Relay with only a 5V signal.

Will I have to use a Ground output to Control a Fuel pump Relay?

which pin should I use and how should I set that up so my computer can safely control my fuel so its not just a Switch (Acc pwr relay)

 

thanks

AEM_NS
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Joined: 06/06/2014 - 09:31
Yes, 16A and 38A are both LS7

Yes, 16A and 38A are both LS7 which has a 12v pull up to be used for a 12v square wave tach signal.  A tach that's expecting a coil primary signal input may not work with a 12v square wave signal.  You'll need to test it to see.  If it doesn't work you'll either need to change the tach or add something to the circuit to generate a coil primary signal.  There's info online about how to do this using a coil from a relay.  Also, FWIW, it seems that most tach signals are 12v, not 5v.

Regarding the fuel pump relay, here's what the instructions say: If an aftermarket fuel pump relay will be installed, wire it to be controlled using a spare low side output (for instance, LS9 is available on pin 68B). Be sure to configure the output to use the Fuel Pump function using Tools>>Configure Outputs.

Raysupra
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Last seen: 2 years 5 months ago
Joined: 08/24/2014 - 12:03
Appreciate it..  So the Ecu

Appreciate it..  So the Ecu will be fine controller a Fuel relay just using a low side output(Ground control) and just configure it as such.. 

Same thing for a fan relay just tell it low side output...

So the AEM should be able to control my Tach then if it as a 12v signal.. I'll have to inspect the tach and wiring and check my settings. appreciate the help.
 

AEM_NS
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Last seen: 31 min ago
Joined: 06/06/2014 - 09:31
If the tach was originally

If the tach was originally hooked up to an ignitor, it may not work with a 12v square wave.  The ignitor would give a coil primary signal which would generally have a voltage spike in it that reaches hundreds of volts which a "clipped" 12v square wave won't have thus it may not trigger the tach.  And yes, any low side can be configured to trigger a relay for nearly any purpose.  You'd just set it up in Configure Outputs.