Blown Fuse - Diesel Forum

DAVID94IDIT · 09-24-2006, 09:45 PM

I have a 94 F350 Turbo diesel 4X4 quad cab with E4OD. Does anyone have a wiring diagram. I keep blowing a 10 amp fuse #18 (Electronic shift mode 4wd; speedometer...) It blew this weekend. My speedometer and odometer will not work. Transmission goes into limp mode. Two weeks ago I installed pyrometer, boost, and trans gauges. I removed those to double check I had not wired something wrong. They were working fine and were not effected by the fuse so the problem does not relate to my wiring. I disconnected the electronic sensor on top of the rear diff. (Speed Sensor?) It still blew new fuse with this disconnected. The problem may be under the dash and don't want to remove it again without a schematic.

cdnsarguy · 09-25-2006, 01:11 AM

Could be the PSOM (Powertrain speedometer odometer module)... Has the trans set any codes.........

Speedo info and wiring pic on the way.......

DAVID94IDIT · 09-25-2006, 06:55 PM

Where is th PSOM located? I found a small connector under the glove box labeld PSOM. I believe this is where you plug into it to program or allows you to change settings.

cdnsarguy · 09-26-2006, 12:57 AM

Should be center of the back of the cluster.......

Check out this post by jrcat......

http://forums.thedieselstop.com/ubbthrea...e=0#Post3044296

DAVID94IDIT · 09-27-2006, 01:07 AM

Tonight I removed the whole instument cluster and light switch. Put in a new 10 amp fuse. As soon as I turned the key it popped. I traced the wire (white w/ blue stipe? I'm color blind) from the fuse box up and behind the vent up to the instrument cluster. Continuity test confirms to #3 PSOM plug. It also has continuity from this plug to ground. Tomorrow I'll cut the wire behind the fuse box and run a wire to the plug. I hate to do this because there is very little room behind the fuse box to splice in a new wire.