JSVD
Full Access Member
On our 89 f250 recently the OD light came on and stays on (dim). The tach stopped working and the tranny is in limp mode. I've researched it and know it could be the EEC relay, the tach sensor, or the ECU for the transmission. I suppose it could be the connections on the transmission, but I feel like the tach would work then?
I've tested the relay and it clicks. Also tested the tach sensor and it has good continuity. I then tested the hot wire comming into the EEC relay and it reads 0 with the truck off. I then tested all the slots where the relay sits for ground, and they all ground out. Never dealt with burnt out wiring, but that leads me to beleive I have a big short in those 4 wires. Am I on the right track?
Is anything else wired with those wires? I'd like to test and see if anything else is grounded out. Also if the ECU isn't getting power would my tach not work?
Anyone have a wiring diagram for an 89 f250 7.3 with the e40d?
I do not have a code reader... could rig up a test light but i'm pretty sure it's in the wiring.
Thanks,
Jared
I've tested the relay and it clicks. Also tested the tach sensor and it has good continuity. I then tested the hot wire comming into the EEC relay and it reads 0 with the truck off. I then tested all the slots where the relay sits for ground, and they all ground out. Never dealt with burnt out wiring, but that leads me to beleive I have a big short in those 4 wires. Am I on the right track?
Is anything else wired with those wires? I'd like to test and see if anything else is grounded out. Also if the ECU isn't getting power would my tach not work?
Anyone have a wiring diagram for an 89 f250 7.3 with the e40d?
I do not have a code reader... could rig up a test light but i'm pretty sure it's in the wiring.
Thanks,
Jared