79 speedo trouble shooting
Thread Starter
Intermediate
Joined: Jul 2016
Posts: 35
Likes: 2
From: Charlotte NC
79 speedo trouble shooting
My speedo is in op. vehicle has cruise control. Started to trouble shoot at the dash input to the transducer. Ran a drill and the needle works. Disconnected the cable at the transmission. Ran the drill and needle did not move. Installed a new cruise control transducer by the numbers and expected the needle to jump off the peg during a test drive...no joy. Dejected after working in such close quarters with the old and new transducer removal and replacement. Does the cable from the transmission To the transducer have a plastic bit on it? I found a plastic bit in side the old transducer, removed it and placed it in the new assembly then reinserted the cable from the transmission and tightened it down. Was this an install mistake and should I have left that out. My speedo cable is relatively new. Is the end of it suppose to have the plastic thread attached or could this be the problem and I need a new lower cable to my transducer.
A lot of words but a lot of work so far with negative results. Prior to failure the needle was sometimes jumping around and not holding steady.
Thank you
7ron9
A lot of words but a lot of work so far with negative results. Prior to failure the needle was sometimes jumping around and not holding steady.
Thank you
7ron9
Instructor
Joined: Jun 2015
Posts: 178
Likes: 34
From: Calgary Alberta
I'm certainly no expert, but I just replace the cruise transducer on my 81 last month. I did not move any plastic bit from the old transducer to the new one.
Is it possible that the old transducer sheared off part of the old cable from the transmission to the transducer and that is what you are seeing? You may want to have a good look at the cable ends.
Is it possible that the old transducer sheared off part of the old cable from the transmission to the transducer and that is what you are seeing? You may want to have a good look at the cable ends.
Thread Starter
Intermediate
Joined: Jul 2016
Posts: 35
Likes: 2
From: Charlotte NC
I'm certainly no expert, but I just replace the cruise transducer on my 81 last month. I did not move any plastic bit from the old transducer to the new one.
Is it possible that the old transducer sheared off part of the old cable from the transmission to the transducer and that is what you are seeing? You may want to have a good look at the cable ends.
Is it possible that the old transducer sheared off part of the old cable from the transmission to the transducer and that is what you are seeing? You may want to have a good look at the cable ends.
Thank you will keep trying...maybe a blow up of the part on line will answer the question.
7ron9
Thread Starter
Intermediate
Joined: Jul 2016
Posts: 35
Likes: 2
From: Charlotte NC
Pro
Joined: Aug 2007
Posts: 707
Likes: 31
From: Pitman NJ
I think the problem is the lower cable. As the transducer wears, it puts more and more tension on the lower cable until it fails. Since you replace the transducer, the new cable should do the trick.
On my 79, ended up with one cable. The old transducer is there for a later time...
On my 79, ended up with one cable. The old transducer is there for a later time...
Thread Starter
Intermediate
Joined: Jul 2016
Posts: 35
Likes: 2
From: Charlotte NC
79 speedo trouble shooting
I think the problem is the lower cable. As the transducer wears, it puts more and more tension on the lower cable until it fails. Since you replace the transducer, the new cable should do the trick.
On my 79, ended up with one cable. The old transducer is there for a later time...
On my 79, ended up with one cable. The old transducer is there for a later time...
7ron9
Melting Slicks
Joined: May 2011
Posts: 2,753
Likes: 119
From: Springfield Missouri
some replacement (universale cables) are cut to length and then heated up and the plastic piece is pressed on, cable allowed to cool and thus you have the right length, only problem is they break off!
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Thread Starter
Intermediate
Joined: Jul 2016
Posts: 35
Likes: 2
From: Charlotte NC
Speedo inop
7ron9