new LS3 swap - RPM signal to Ultima RPM gauge not working

[2001ultima]

All,

Swapping an LS3 into a 2001 Ultima. There is an RPM reading/gauge issue, no reading. Do you recall with any recent LS3/7 builds the ECU wire used and did you connect to the Ultima RPM gauge directly with no issue? Did you need to configure the RPM gauge anyway or is there and adaptor needed?

Thanks,

Jim

[SchimmS]

2001ultima said:

All,

Swapping an LS3 into a 2001 Ultima. There is an RPM reading/gauge issue, no reading. Do you recall with any recent LS3/7 builds the ECU wire used and did you connect to the Ultima RPM gauge directly with no issue? Did you need to configure the RPM gauge anyway or is there and adaptor needed?

Thanks,

Jim

Hi Jim,

there should be 2 wires on the engine wiring harness that connect to the RPM and speedo (usually white for RPM and green for speedo). If you have no RPM you to use a pull-up resistor (I think around 1 kOhm) from a +12V source to the RPM wire and you should be OK.