Driving today I noticed that my speedometer and odometer stopped working. I replaced the blown fuse (#18) and turned the ignition on and it worked for a second then blew the same fuse again. Checked for codes and there are no codes in the KOEO/KOER. The #18 fuse reads 12.2 with KOEO and 14.2 with KOER on the hot side and zero on the other side (no fuse in). The VSS looks good (unplugged and inspected/not sure how to test it and don't want to change parts for nothing) and the ABS light is not on. My truck has the M5OD so the only thing that fuse #18 powers is the speedometer and the Air Bag Restraint (according to the fuse block). Fuse #8 is working fine (Tested with meter) and all associated items work (dome/cargo lights, radio memory for my XL) EXCEPT the speedometer (but again that fuse is good). Any guidance on what to test first/next is appreciated.

Speedometer/Odometer quit working at just under 180k

Fuse panel position/ID

Fuse panel description (#8 and #18 are of concern)

 

Instantly blowing a fuse is a major symptom of a shorted wire.

 

Shagg,
That is what I was thinking and I was also thinking that it is weird that all of a sudden it just shorted out. My question is now, where do I start looking; behind the fuse block, in the steering column/ignition?

 

Yeah, I had a funny "burning" smell in the cab of my truck yesterday morning and then I noticed my tach stopped working. Didn't blow any fuses though, but if I remember correctly, the last time I had the gage cluster out putting in LED lights, I had some issues with the red ribbon connector so I'm going to take a look at that. Dashworth, maybe take a look at your gage cluster and see if there are any obvious issues...

 

C6,
I am going to start to tackle this today. Might as well start with the gage cluster and see how it all looks. I did not smell any burning when I noticed my speedo not working so hopefully that is a good thing. Thanks for the reply.

 

I removed the cluster and took it all apart. I did not see anything that looked burnt, bubbled, or black (of course I am not sure what to look for). Below are some pics of the back of the cluster for anyone to provide guidance if they see any possible issues. Does anyone have a complete wiring diagram for a 95 F150? My Haynes manual has a crappy and incomplete diagram. I checked continuity from fuse to odometer plug (backside and it was good) Obviously no voltage due to fuse not being in. Put everything back together put in a fuse and turned the key to the ACC position and the odometer came on but as soon as I turned it to start the truck I heard the fuse pop. Guidance and thoughts appreciated.

Back of PSOM

Driver Side Close up of Cluster

Passenger Side Close up of Cluster

Zoom in of harness insertion. I see discoloration between circuits but everything was and is working.

Zoom in of harness insertion (other side) with some discoloration also.

 

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Steve,
Thank you for the reply and the great information. The link you have for BBB Industries no longer offers Tech Support/Information/wiring diagrams Great information. Do you have a wiring diagram for a 95 that shows the ABS and speedometer/odometer information? I checked the RABS voltage and
it appears to be okay between 0-3.4v as speed increases. I am going to start going through the ABS parts (grounds/wires) for issues. Thanks again for your help and guidance/wisdom.
BBB no longer offers TSBs and wiring diagrams. We apologize for the inconvenience.

 

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Steve,
Thank you again for your knowledge and guidance. I pulled the ADM after unplugging it (and no fuse blowing) to find the white/black fusible link/capacitor is bad. The rest of the unit looks okay. What years/model of vehicles can I look for to pull a couple of these out of? Why the price difference on Ebay ($18-$89 varying years with 95 and older being more)?