After doing some work on my truck all of my needles have stopped working. My truck is a 98 f150 w/ tach. Ive swapped clusters and still no dice. Also used my multi-meter to test some of the connectors and I think I may have narrowed it down to a bad ground however I dont know where the wires ground out to. Here is a picture of the connector I believe has the bad ground.... Also checked all instrument cluster fuses and they were good.



Has anyone had any similar issues before? I need some wiring diagrams to troubleshoot this more, any help is appreciated.

 

Not too sure what connector number that is, or if it has a ground in it ( might not ).

Here are the instrument cluster diagrams

















That looks like a 12 pin connector, but I am taking a SWAG by looking at it, trying to do pin layout.

3 of the pins are not used, but I do not have a way to tell which number they are ( it is left to right 1 to 12 or right to left ? ).

 

Thank you for the diagrams. From counting the connector it looks like a 13 pin to me. Its the connector that is just behind the tachometer. From the looks of it, i should have atleast a few needles working if it was a bad ground on the connector. Maybe there is a ground that they all tie into?? Maybe im missing a relay or something??

I know that Ive got lights on the cluster just no needle movement what so ever.

 

On diagram 62-2:
There is a single common ground for all the gauges, Pink w/ Orange Stripe wire.
The solid state control has a ground with Black w/ White stripe wire ( changes to a Black w/ light blue stripe wire after splice S208 ).

Cluster illumination is a different connector that has 2 grounds in it, both are black wires ( pins 1 & 12 in connector C236 ). This is shown in summary on 62-7, the details are in EVTM cell 71. Two different systems on the truck, so one can work without the other being operational.

Did you check for power on the pins on the back of the fuse with the fuses installed in the slots ?
- Keep in mind one is hot at all times, the other 2 are hot in run position. The PCM connection I do not have the diagrams handy at the moment, but this could also be a power source.

The gauge you swapped in for testing, is this a known good operational cluster ?

 

So we are talking maybe the vehicle speed sensor ground, which I can see now ties into all gauges on 62-2. Roger on checking the fuses, I was touching both sides with the multimeter for DC while the ignition was in the ON position.

Here is something im going to try-

Im just going to strip both of the ground wires as discussed above, then connect a jumper to a known good ground and see if that does the trick.

Also, the cluster is something I pulled out of a junk yard, and the part is guaranteed to be operational. However I myself have never seen it function.

 

The VSS ground is connected at the same point, but the ground for the gauges is on pin #5. The solid state control is on pin #8.

Instead of cutting apart the connector, why not use a meter to check from those wire colors / pin numbers to a known good ground. If there is continuity then the ground is good.

You are still at the point of you cannot be sure that you don't have 2 bad clusters ( how was the part actually verified to be operational in a truck ? ).

Start with checking for the power at the connector and checking the 2 ground pins to a known good ground for continuity.

 

My grounds are good for a fact. I just checked them and read 2-4 ohms. Now im moving on to power. Both #2 and #29 fuses are good for continuity and power, so must be a short on either wire 640/RV or wire 729 R/W those are the two wires that supply power for all needles from what I can see (correct me if I am wrong)

 

No power at Yellow White, Gray Orange wires. Y/W runs to Solid state from fuel pump module. G/O runs from inertia fuel shut off, not expecting power there--

I have power at wires; White Yellow (Fuse 19 10Amp), Red Yellow (Fuse 29 5Amp), and Red White (Fuse 2 5Amp)

Its got to be a common short or bad ground somewhere. How does the solid state control work? What voltage should it read? Is there an actual layout of pin numbers on these connectors? If so how are they numbered?

 

My battery is dead and doesn't hold a charge for sure too. Even though I have it hooked up to a charger and its sending 12v, is it possible that the cluster doesn't work even when its running, turns out my radio doesn't work along with my power windows. I noticed that my RPM gauge sometimes would jump under load...

 

SSCULLY,

After further inspection, my windows, radio, insturment cluster and wipers are not working. Is it a possibility my GEM is causing all of this trouble??

 

Could be the GEM, but did you check the fuses in the Engine Compartment fuse panel, with a meter on both pins on the back of the fuse while installed /
- This is + probe on a pin on the back, to a known good ground, then check the other pin.

Fuse #22 is coming to mind with the list you have ( feeds the cab fuse panel )

If that tests OK, might want to check the floor behind the driver's side kick panel for signs of water damage ( leaking windshield ).

 

I remember checking all fuses for both continuity and voltage but I guess it wont hurt to look twice, I am going to swap batteries tonight aswell. Then I will check for signs of water damage. Thank you for all of your help.

 

Fixed! Dead battery!! So I guess even when the truck is in idle and the battery is dead they still dont get power... interesting. Thanks SSCully!

 

What year did Ford F 150 begun using digital odometer?

 

1992-1996 were digital, then 1999 and newer.