Need help please to identify the problem!!

[72Z/28]

Originally Posted by blitzer454

I agree you may need a pull-up resistor if you're using an LS ECM for tach signal. But I think the recommended value is a 5K 1/4 watt resistor so you might want to verify that value for the ECM that you're using.

Perhaps you won't see anything on the speedo at slow speeds until after you get the speedo calibrated. So maybe focus on getting the tach to work first then wait until you get the car on the road before worrying too much about the speedo.

Actually I ordered 1K ohms 1/4 watt resistor as it was recommended in some forums. Hopefully it will work. I have not connected it yet to see if the tach will respond or not.

As you said, may be I need to wait till I get the car back on the road to check the speedometer.