I got my first truck today and it's a 1988 Ford F-150 and it runs great! The only issue is that the speedometer dosent work and I won't be able to register it until it does. I was wondering what I can try out to maybe fix the issue and if not, how I would replace it. Every other guage works, it's just the speedometer that isn't. The needle dosent move at all it just sits at a 0 all the time. Any help is appreciated, thanks!

 

welcome to FTE.
the speedometer in an 88 is cable driven.
there are a few ways to test it. one way is to pull the cable out of the back of the trans, hook a drill to it, and see if the speedometer moves. if it does, the problem is in the drive gear on the cable, or the drive gear in the trans. if it does not move, than the problem is either a broken cable, or a bad speedometer head.
usually the plastic drive gears wear to the point where they no longer mesh. or the cable breaks.

 

Where would the cable be located at? I'm not sure where too look and I don't really want to take anything apart until I know just so I don't mess up any other gauges

 

IIRC the VSS/vehicle speed sensor plugs into the drivers side of the transmission and the speedometer cable plugs into the VSS.

If the cruise control works the gear in the transmission and the gear on the VSS are OK, and you need to check for a broken speedometer cable or speedometer.

 

If you have 4x4, the speedo cable plugs into the transfer case. Not sure about the vehicle speed sensor, a lot of them where mounted on top of the rearend. The vss is not your problem, but like the other poster mentioned you may encounter it depending on what setup you have.

 

as Dave said, on 4wheel drive the speedometer cable goes into the tail shaft of the transfer case. on two wheel drive it goes into the tail shaft of the transmission.

 

Before I start a new thread on this... my '88 F800 has an electrically actuated, not cable, speedometer and odometer. The former works great, the later, not at all. Any ideas on what I should be searching for (as in google search) to try and get some info on how to fix this thing?

 

f-800 is a completely different animal than the F-150 through F-superduty trucks, and pretty much nothing on them is the same except for the ford name.

 

The speedometer works, the odometer doesn't? If that is the case, they are made together correct? The ones I have worked on, it was a gearing problem inside the speedometer.

The speedometer is usually a round metal drum with a magnet on it, and as it spends the magnet acts on the speedometer needle which is spring loaded. The faster the drum spins with the magnet, the more it pulls the needle up and around the scale. Coming off this drum is also a transmission of sorts, and it turns gears that are attached to the odometer numbers. I have seen them pop the gears out of position when a large load appears, which is usually a combination of 9's. When a bunch of 9's come up, several sections need to turn at once and this is usually when they stop working.

 

Hey guys my 88 f150 has no speedometer cable. It's a 4x4 with a C6 transmission. Just happens I have a an extra cable from a 91 f150 2w drive with a E4od transmission. Will they switch ???

 

probably not.

 

If you can find a parts store or a vendor that sells new ones, see if they sell the same part number for both trucks.