HELP! My Speedometer Quit on Me!!
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,625
Likes: 0
From: Cut n Shoot TX
HELP! My Speedometer Quit on Me!!
I took my Vette out for a cruise over the weekend and at some point the speedometer just quit working. Now I know that a transducer that is going bad will cause the speedo needle to bounce, and mine did onece in a while. But what my questions are:
1- Will the transducer just go bad all at once?
2- How can I be sure it is the transducer that is to blame?
3- How the heck to you remove that transducer? I do not see how it is bolted in.
Thanks in advance!!
1- Will the transducer just go bad all at once?
2- How can I be sure it is the transducer that is to blame?
3- How the heck to you remove that transducer? I do not see how it is bolted in.
Thanks in advance!!
Drifting
Joined: Mar 2001
Posts: 1,411
Likes: 2
From: St. Louis, Missouri
Re: HELP! My Speedometer Quit on Me!! (VettePower)
1- Will the transducer just go bad all at once?
Yep.
2- How can I be sure it is the transducer that is to blame?
When you remove it, the input connection should spin freely, if it is binding, it can break the lower cable
3- How the heck to you remove that transducer? I do not see how it is bolted in.
There are two bolts on either side of the transducer that hold it to the mounting bracket. The outboard one is tough to reach but it can be done.
Yep.
2- How can I be sure it is the transducer that is to blame?
When you remove it, the input connection should spin freely, if it is binding, it can break the lower cable
3- How the heck to you remove that transducer? I do not see how it is bolted in.
There are two bolts on either side of the transducer that hold it to the mounting bracket. The outboard one is tough to reach but it can be done.
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,625
Likes: 0
From: Cut n Shoot TX
Re: HELP! My Speedometer Quit on Me!! (Neo Fender)
My cruise control also stopped working when my speedo stopped. Is this also a sign that the Transducer went bad. I'd hate to buy a new transducer when that isn't the problem.
Melting Slicks
Joined: Aug 2000
Posts: 2,310
Likes: 1
Re: HELP! My Speedometer Quit on Me!! (VettePower)
"My cruise control also stopped working when my speedo stopped. Is this also a sign that the Transducer went bad."
Not necessarily.
My speedo stoped working because the lower cable (from the trans to the CC transducer) broke at the transducer end. If that lower cable breaks anywhere, or the speedo gear in the trans loses teeth or otherwise breaks, you won't have speedo or cruise.
You should be able to get your hands on both connections on the transducer without taking it out.
I'd start by removing the upper cable from the transducer. Check the tip to make sure it's not broken off. You can then hook a variable speed, reversible drill to the cable (carefully :eek: ) and run the drill in reverse and see if the speedo needle moves. If not, your upper cable could be broken or the speedo itself could have problems. If the speedo does move, then it's time to move to the transducer and lower cable.
The next thing I'd do is remove the lower cable from the transducer and inspect the tip. If it's OK, I'd try to spin the cable with my fingers. If you can spin it, the cable may be broken or you may have a speedo gear problem. You could also hold the cable, get in the car, and drive slowly to see if the cable moves.
The transducer bolts, as stated already, can be a PITB to get to, but it's not all that bad to get out.
This should get you started. Good Luck.
Not necessarily.
My speedo stoped working because the lower cable (from the trans to the CC transducer) broke at the transducer end. If that lower cable breaks anywhere, or the speedo gear in the trans loses teeth or otherwise breaks, you won't have speedo or cruise.
You should be able to get your hands on both connections on the transducer without taking it out.
I'd start by removing the upper cable from the transducer. Check the tip to make sure it's not broken off. You can then hook a variable speed, reversible drill to the cable (carefully :eek: ) and run the drill in reverse and see if the speedo needle moves. If not, your upper cable could be broken or the speedo itself could have problems. If the speedo does move, then it's time to move to the transducer and lower cable.
The next thing I'd do is remove the lower cable from the transducer and inspect the tip. If it's OK, I'd try to spin the cable with my fingers. If you can spin it, the cable may be broken or you may have a speedo gear problem. You could also hold the cable, get in the car, and drive slowly to see if the cable moves.
The transducer bolts, as stated already, can be a PITB to get to, but it's not all that bad to get out.
This should get you started. Good Luck.
Melting Slicks
Joined: Jun 2001
Posts: 2,414
Likes: 1
From: Forest Hill Md
Re: HELP! My Speedometer Quit on Me!! (VettePower)
Add on question,
Does the transducer have any gear reduction inside or is it a 1:1. If I bypass the transducer with a speedo cable for a non cruise control car, will the speedo be accurate? ie: direct from the tranny to the speedo without the transducer gearing down or up? :crazy:
Does the transducer have any gear reduction inside or is it a 1:1. If I bypass the transducer with a speedo cable for a non cruise control car, will the speedo be accurate? ie: direct from the tranny to the speedo without the transducer gearing down or up? :crazy:
Melting Slicks
Joined: Jul 2002
Posts: 3,000
Likes: 22
From: Boulder Creek California
Re: HELP! My Speedometer Quit on Me!! (n8370c)
Question about the 'bouncing' you mentioned. After I've been driving a while my speedo needle starts to bounce quickly about 10mph on each side of true speed. It seems to be heat related (stopping for a while will cure it temporarily) so I had guessed the cable heated up, expanded and was grabbing the inside of it's tube as it spun. Am I wrong and it's a transducer problem instead?
Thanks,
Chris
Thanks,
Chris
Drifting
Joined: Feb 2002
Posts: 1,987
Likes: 3
From: Manchester, Dead Center in the Middle of TN 25 miles to Jack Daniels,10 miles to Geo Dickle, and .8 mile from the Liquor Store at I-24 Exit 114
St. Jude Donor '05
Re: HELP! My Speedometer Quit on Me!! (jerryp58)
Transducers are not just exclusive to the Vette. Cutlass, GP, and others also fit. I need to get a print out from thre Hollander computer on the Windshield Wiper motors, 81 ECM boards, transducers and other parts that interchange with many G-body or A-boy cars and put it in the Tech Section for the 77 - 82 years.
Let me know what the problem is and I'll try to get the info on a transducer for you.If it is a speedometer I have a couple of extras stuck back for a '78-'82. I am thinking the 77 is the same?
The ones I have are 85 mph. However, you can send one to Redline Tach & Gauge and he can put your 140 face on it or maybe even fix your speedo.
If he puts on one of his new faces and recalibrates an 85 mph to 140 it is only $57.00 I think he charges only $20 bucks or so to change your face out and recalibrate .
Let me know if I can help. JIM
Let me know what the problem is and I'll try to get the info on a transducer for you.If it is a speedometer I have a couple of extras stuck back for a '78-'82. I am thinking the 77 is the same?
The ones I have are 85 mph. However, you can send one to Redline Tach & Gauge and he can put your 140 face on it or maybe even fix your speedo.
If he puts on one of his new faces and recalibrates an 85 mph to 140 it is only $57.00 I think he charges only $20 bucks or so to change your face out and recalibrate .
Let me know if I can help. JIM
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