dakotaguy1999
NAXJA Forum User
- Location
- Fairbanks, AK; Kodiak, AK
Hello there,
My friend has an '86 2.5 XJ and we have installed a full-gauge cluster from an '89 4.0. Once we got the speedometer cables swapped out - everything worked great, except the tachometer was reading lower than it should. I suspect this is because the cluster came off of a rig w/ the 6cyl.
I have done the swap on a 91-newer XJ, and I know the tach signal came directly from the PCM. I've swapped in a tach from a 4.0 into the 2.5 on one of the 91-later models, and the tach was more or less accurate. I am not sure about the 84-90 clusters though - it appears the tach signal comes directly from the ignition module.
I was looking at the back of the tach cluster, and there is some sort of resistor mounted in the printed circuit board behind the tachometer. Does anyone know if this resistor has anything to do w/ the tach calibration? If so what will I need to replace it with in order to get the tach to read correctly for the 2.5L? Or is there some alternative way to calibrate the tach?
Any help would be greatly appreciated! Thanks in advance!
My friend has an '86 2.5 XJ and we have installed a full-gauge cluster from an '89 4.0. Once we got the speedometer cables swapped out - everything worked great, except the tachometer was reading lower than it should. I suspect this is because the cluster came off of a rig w/ the 6cyl.
I have done the swap on a 91-newer XJ, and I know the tach signal came directly from the PCM. I've swapped in a tach from a 4.0 into the 2.5 on one of the 91-later models, and the tach was more or less accurate. I am not sure about the 84-90 clusters though - it appears the tach signal comes directly from the ignition module.
I was looking at the back of the tach cluster, and there is some sort of resistor mounted in the printed circuit board behind the tachometer. Does anyone know if this resistor has anything to do w/ the tach calibration? If so what will I need to replace it with in order to get the tach to read correctly for the 2.5L? Or is there some alternative way to calibrate the tach?
Any help would be greatly appreciated! Thanks in advance!