Speedometer problems?

[-Willow-]

Hey everyone I just got a 84 bronco ii XLT not too long ago, and the speedometer doesn’t work and I was wondering if it is a common problem and how to fix it.

 

[tw205]

First trace the cable at both ends and make sure it’s connected. A cable coming thru the floor by the gas pedal is the speedometer cable. A hand fumbling around under the dash a can easily disconnect it from the back of Speedo. People also would disconnect them to make the mileage lower. ( sneaky bastards) The other end should plug into the rear of the transfer case. Let us know what you find. I’ve had 5 BIIs and none had a broken speedo. f

 

[-Willow-]

So I looked and everything was plugged in right,and nothing was loose but I took it out on a drive today, and when I got on the highway through my town I got up to probably about 45-50mph, and the speedometer started jumping between 15 and 30 I think it might be the VSS sensor on the transmission by the driveline.

 

[-Willow-]

First trace the cable at both ends and make sure it’s connected. A cable coming thru the floor by the gas pedal is the speedometer cable. A hand fumbling around under the dash a can easily disconnect it from the back of Speedo. People also would disconnect them to make the mileage lower. ( sneaky bastards) The other end should plug into the rear of the transfer case. Let us know what you find. I’ve had 5 BIIs and none had a broken speedo. f

Also my blinkers work but the green lights in the cluster don’t come on when I turn on my blinkers

 

[RonD]

Bronco II's all use speedometer cables, if there is a VSS then it was used for cruise or computer, not speedometer

You will need to pull the Speedometer Driven gear out of transfer case and have a look at it
One bolt and you can pull out the speedo cable and with its Driven Gear

Looks like this: https://www.therangerstation.com/tech_library/images/speed/speedocable_withgear.JPG

If it also has a VSS then it will look like this: https://www.therangerstation.com/tech_library/images/speed/vss_withgear.JPG

The speedometer cable runs the speedometer either way

You can take an electric drill and spin the speedometer cable while its off, that will tell you if cable may be the issue, or speedometer itself
Use reverse-able drill, can't remember which way it spins, but won't hurt it to spin it backwards, thats what you do every time you back up, but no speed will show


Could just be burned out bulbs in the dash
Check speedometer first
Then if you have to pull the cluster you can check the bulbs

 

[-Willow-]

Bronco II's all use speedometer cables, if there is a VSS then it was used for cruise or computer, not speedometer

You will need to pull the Speedometer Driven gear out of transfer case and have a look at it
One bolt and you can pull out the speedo cable and with its Driven Gear

Looks like this: https://www.therangerstation.com/tech_library/images/speed/speedocable_withgear.JPG

If it also has a VSS then it will look like this: https://www.therangerstation.com/tech_library/images/speed/vss_withgear.JPG

The speedometer cable runs the speedometer either way

You can take an electric drill and spin the speedometer cable while its off, that will tell you if cable may be the issue, or speedometer itself
Use reverse-able drill, can't remember which way it spins, but won't hurt it to spin it backwards, thats what you do every time you back up, but no speed will show


Could just be burned out bulbs in the dash
Check speedometer first
Then if you have to pull the cluster you can check the bulbs

Okay thank you very much, this was very informative and also mine has a VSS but I don’t use cruise control so I’m not gonna worry about that then.
Also will transmission fluid come out of the hole where the speedometer gear is when I take it out?

 

[RonD]

No, no fluid would come out