AFTERMARKET TACHOMETER CONNECTION TO AN RB20DET

[Storminn45]

My son has a 1990 240sx, I put an RB20DET into. I am trying to get a SunPro aftermarket Tach to work. I can't It is connected to the # 7 pin. Lights work, no signal on the tach. What should I do? I changed the tach twice. Still the same thing.

[Sil240]

Put a multimeter on there and see if you get any kind of signal out of there.If not then you need to do like me.You need to get a Dakota Digital Tach Adapter.It takes the signal direct from the coil packs.The cheapest I found it was Phoenix Tuning in GA.

[lanerjo]

the easiest way to fix this issue is to go to radio shack and get a 10k ohm resistor... a pack of 5 is $0.99 wire the resistor from the power wire to the signal wire... This is called a pull-up resistor... [IMG][/IMG] [IMG][img=http://img206.imageshack.us/img206/866/ ... lk2.th.png][img=http://img206.imageshack.us/images/thpix.gif][/IMG]

[Carl H]

pull up resistor will not work on a single cam tach and have yet to prove that it works on a twincam.

[pepegurr]

most sunpro tachs will not work without some form of signal converter, bad thing is most of the converters cost more than the sunpro tachs . your best bet is to find an autometer that will work with the rb. a friend of mine that runs my local autozone let me try all the ones they keep in stock (sunpro, faze and autometer)and NONE of the tachs they keep in stock will work without a converter. hope this helps.

[Carl H]

you must be doing it wrong because i have used several different sunpro tachs to verify tachometers on cars...i even have a sunpro gauge from the straight up 70's that reads the nissan generated ecu tach signal.

[pepegurr]

im sure im not doin it wrong, i think its just the selection of tachs the local stores here have are just severely lacking. my local stores cater more to the distributer compatible cars . would you happen to have a model number for one of the known usible ones cuz im still looking for one for my swap.

[Carl H]

i can modify the stock tacho to work properly for about the same price you'd pay for one of the ugly aftermarket ones.

[lanerjo]

pull up resistor will not work on a single cam tach and have yet to prove that it works on a twincam.

the diagram is how to get the signal from the rb ecu to have enough strength so that an aftermarket tach will work... It is simple costs next to nothing

[FinkenS14]

the easiest way to fix this issue is to go to radio shack and get a 10k ohm resistor... a pack of 5 is $0.99 wire the resistor from the power wire to the signal wire... This is called a pull-up resistor... [IMG][/IMG] [IMG][img=http://img206.imageshack.us/img206/866/ ... lk2.th.png][img=http://img206.imageshack.us/images/thpix.gif][/IMG]

Im having this exact problem with my RB25 S14 right now. Got a SunPro tach, lights turn on, tach jumps to 0rpm with key on, but no movement or signal when the car is running. I tryed ECU pin #7, and got nothing. So my next thought is im going to try this resistor trick. How exactly is this resistor fixing the problem?

[FinkenS14]

the diagram is how to get the signal from the rb ecu to have enough strength so that an aftermarket tach will work... It is simple costs next to nothing

Nevermind, that just answered my question, thank you. Ill get back to you guys if this s*** works.

[jacksonbrown]

MSD DIS Tach Driver PN-8913, have it on my sons RB25 that had same problems. Works great at about $90.

[FinkenS14]

the diagram is how to get the signal from the rb ecu to have enough strength so that an aftermarket tach will work... It is simple costs next to nothing

And your sure of this?