Ron McDowell
New Member
Any suggestions men ...73 Newport
speedo not working
- Thread starter Ron McDowell
- Start date
Justin Plant
Well-Known Member
Try diagnosing the cables. If it has cruise, there will be two. One to the cruise unit and from it to the speedo. In my experience the lower one gives out first.
57fury440
Well-Known Member
Has it worked since you have owned the car? If not check to see if it has a cable and if it is attached to the transmission.
With the car on a safe lift, unhook the transmission cable from the transmission tail shaft. Use a narrow blade screwdriver to see if the speedo driven gear will turn or not. If it turns more than just to the normal slack from the two gears meshing, then that gear is worn and will need to be replaced. If it is still tight, then try to rotate the inner speedometer "cable". If it turns freely, then the cable might be either broken inside of the casing or still intact. Possibly the resistance felt can give a hint of these things?
Then re-index and install the cable into the speedo driven gear and put things back together. Then find where the speedo cable goes into the back of the speedometer head. Is the cable still tight or does it move freely. If it moves freely, the cable is broken.
IF the car has a cruise transducer under the hood. Then you can unhook the cables there and check them from there. Bottom one (to the transmission) should not turn, but the upper one (to the speedometer head) should turn freely. If you have an electric drill motor, you might install the unhooked cable end into the drill to see if the speedo needle moves. At the cruise transducer end, I suspect the cable will need to turn CCW for speed to register?
Please keep us posted on how things progress,
CBODY67
Then re-index and install the cable into the speedo driven gear and put things back together. Then find where the speedo cable goes into the back of the speedometer head. Is the cable still tight or does it move freely. If it moves freely, the cable is broken.
IF the car has a cruise transducer under the hood. Then you can unhook the cables there and check them from there. Bottom one (to the transmission) should not turn, but the upper one (to the speedometer head) should turn freely. If you have an electric drill motor, you might install the unhooked cable end into the drill to see if the speedo needle moves. At the cruise transducer end, I suspect the cable will need to turn CCW for speed to register?
Please keep us posted on how things progress,
CBODY67
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