Re: 1990 f350 No overdrive and no tachometer
A dead tach sender should/would send the automatic trans into a "failure management mode" (limp mode) with harsh engagements and firm shift feel and an abnormal shift schedule. It has no effect on a manual trans only the Tach readings.
Check the wires where they exit the big nut on the oil filler housing , known to short out due to bare wire.....
Replace the tach sender on the oil fill housing a big 1" nut with 2 wires. Ford only part Engine RPM sensor E5TZ-17B384-A about $50. You can remove and clean it but usually changed later too.
You can test it too, hold it in the air away from ferrous metal, using an ohm meter lead on each wire you need DC resistance between 2000-3000 ohms.
93 F250 7.3 IDI S/C XLT 4X4 E40D 3.55LS, Captains chairs, Tutone Mocha, Leer 48" Hiboy cap, FR & RR hitches, full DeeZee running boards. Factory ordered/delivered Jan 93
Toys: 2006 37' Triple E Embassy coach (powered by Cummins), 18' Sylvan Pro Fish with Mariner motors.
Proud Canadian BOOB man too!!
Please PRIVATE MESSAGE only!! ...
Please DO NOT.....visitor message me...