1988 Xr3I Rev Counter Stop Working Help Mfi

[Guest Fordstevie77]

i all need help with my rev counter it does not work at all

speedo and fuel/temp ok

have had it out to check the wiring/multiplugs and that seem all fine????

any help in right direction appreciated

its the MFi xr3i

[gingergman]

green wire from the coil?

[Guest Fordstevie77]

is that the green wire that accompanys a red one that goes to little black box next to the coil?

[Guest Fordstevie77]

Right checked the green wire inside dash plug only getting 0.22 volts....?

what is no 138 on diagram - SUPRESSOR do would this be causing my problems see wiring diagram below:

[Guest Fordstevie77]

From coil negative the green/red wire goes to suppressor box then out suppressor box to green wire multiplug in dash to clocks

 

I am getting 12 volts give or take at coil negative before it enters suppressor

 

At suppressor out conector I am getting around 5-6 volts ( so suppressor is halfing the voltage)

 

At the mutliplug wire 2 green I am only getting about half a volt 0.5

 

 

[Guest Fordstevie77]

Am i supposed to be getting 12 volts at the plug or 5-6 volts that after suppressor is showing or more/less volts...?

If i by pass the suppressor and connect the 2 wires up the rev counter works but very strangly as idles at about 400rpm and wont rev over 2000-2500rpm when i hit the throttle

[Guest Fordstevie77]

Right sorted it at last it was actually Green/Red wire from my coil which goes to the (Black) speed sensor relay then to the Fuel pump purple relay then its a Green Wire that goes to the Instrument Panel Pin 2 = RPM

So I was looking in the wrong place got thrown looking for green wire when all along it was green/red wire from coil then past 2 relays and finally to its destination the instrument panel