Speedometer Issues..VSS?

[Jsko]

I've been searching around trying to find answers and it seems there could be a few different possibilities. The cluster, VSS, ground, or a bad battery. I am looking for a second opinion if anyone had similar issues.

My issues was at first very random, once a week the speed would jump around from 30-130, all other gauges worked fine. Now since it has been colder in the mornings the speedometer will sit at 0, for about 8 miles or so. The odometer wont read or will turn to dashes during this time. After about 8 miles everything starts to work. If the speed does work and drops to 0 while I am driving I can feel a slight loss of power.

My battery is getting good voltage (12.7) so I think that is not the issue. I would think if it was a ground or cluster issue the other needles would not function. I used a OBDII Scanner to watch my speed and it also shows at 0. Would this confirm it is the Vehicle speed sensor? I figured if the cluster was bad and reading 0 the OBDII would actually display the correct speed. The scanner is not pulling any codes either.

If someone else had the same or similar issues I'd love to get confirmation or advice.

Typical Morning:

 

[FORDSVTPARTS]

You're only getting 12.7v at the battery while the car is running? Should be higher.

My first guess is a charging system issue, check grounds, check the battery cables, I've seen more and more issues with cables as the cars get older.

It's possible the cluster is going bad but not terribly likely.

Any other electrical glitches? Go out at night and fire up the car and turn on everything, lights, stereo, fans etc and see if all the lights start flickering.

-Steve



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[Jsko]

You're only getting 12.7v at the battery while the car is running? Should be higher.

My first guess is a charging system issue, check grounds, check the battery cables, I've seen more and more issues with cables as the cars get older.

It's possible the cluster is going bad but not terribly likely.

Any other electrical glitches? Go out at night and fire up the car and turn on everything, lights, stereo, fans etc and see if all the lights start flickering.

-Steve


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I got the 12.7 from OBDII scan not running.

I haven't noticed any other electrical issues with driving the car at night. I can turn everything on tonight and see what happens. The only thing I did notice on 2 separate occasions was my heated seat didn't get warm until the speedometer corrected itself. I looked at some circuit charts and they seem to share nothing in common, so I don't know what to think of that.

 

[Jsko]

I checked the visible wiring and it seems to be good. The positive side looked a lot newer vs the ground, it may have been replaced already. I did check the voltage with a multimeter and it appears to be lower than normal. The OBDII voltage reading wasn't accurate. I checked out the code of the battery, and it puts it at 11/03 so I am going to replace this due to age alone.

Off: 12.29
Idle: 13.80
Idle w/ Lights & Heat Blower: 13.72

 

[NitrousExpress]

Sounds like something in the charging system. I hope you find the problem quickly!
Good luck buddy!

-Garrett

 

[FORDSVTPARTS]

Check the other grounds, one from just above the alternator to the body and one from the negative cable to the body by the washer fluid reservoir.

The cables can be visually fine but the get corroded inside the insulation which limits the amperage that can flow through the cable kind of like a clogged water pipe in your home.

 

[Jsko]

Everything is working now. It ended up being the connector wasn't fully snapped into the sensor. I also checked out the charging system again with a new multimeter and everything is in normal range. Thanks for the help Steve.