Speedometer acting funny - need some help
Thread Starter
Race Car
Joined: May 2005
Posts: 4,902
Likes: 13
From: The Bluegrass State
Speedometer acting funny - need some help
I did a search and of course it mostly covers the odometer gears. I am replacing the odometer gears on Wednesday, but noticed on a drive this AM that the needle stays at 0 until I hit about 15mph. When I hit 15 MPH the needle jumps from 0 to the correct speed of 15 MPH. The needle works perfectly through all speeds with no jumping or incorrect readings. It just jumps from 0-15 MPH from a dead stop to 15 MPH. If I slow down to 5 MPH and get in the gas the needle works fine also. So the issue is from a dead stop to 15 MPH. Since I am doing the odometer gear swap on Wednesday should I do anything else or should I check the sending unit since it is electrical and not gear driven. Also where is the sensor if I need to look at that? Thanks for all the help.
Mike
Mike
Instructor
Joined: Sep 2012
Posts: 204
Likes: 5
From: San Mateo, CA
Started having this same issue yesterday. Searched and found a few threads with similar problem but didn't find any that offered solutions so I thought I'd revive this one in hopes of some suggestions to correct it. Speedometer needle not immediately rising when accelerating from a dead stop. Odometer works fine. Speedometer works fine once the needle pops up to the correct speed.
I did flick the speedometer glass one time when this occurred which immediately resulted in the needled popping up from 0 to the correct speed of around 15 mph.
Anyone else have this problem and figure out the cause?
I did flick the speedometer glass one time when this occurred which immediately resulted in the needled popping up from 0 to the correct speed of around 15 mph.
Anyone else have this problem and figure out the cause?
Nordschleife Master
Joined: Jul 2007
Posts: 5,613
Likes: 52
From: DFW, TX
I suspect this might be caused by the f'd up odometer gear. I say this cause my odometer failed last wk (was professionally repaired only 3yr, 7k mi ago, WTF) and I noticed that now my needle is doing a bit of periodic jumping around behavior.
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Banned
Joined: Oct 2011
Posts: 5,464
Likes: 31
From: Oregon
I'm jus sayin...
EDIT
And here we are 6 mos down the road, and narry a peep!
Maybe it's just like his status as a "user". True to all aspects of the word/title/status
Last edited by nine9six; Apr 4, 2015 at 06:46 PM.
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Verdad Gallardo
Instructor
Joined: Apr 2011
Posts: 122
Likes: 1
From: Alexandria, VA
Mine did (is doing) this.
It began with a wobble in the speedometer while driving, then to the stays at zero before suddenly begin working, to be followed by completely dead.
I sent if off to North Hollywood Speedometer for repair. The technician said they replaced the circuit board. He said the gears were fine.
It's worked fine for about six months but is now acting up again.
Any ideas why the problem would reoccur?
The speed sensor was replaced a month before the speedometer repair.
It began with a wobble in the speedometer while driving, then to the stays at zero before suddenly begin working, to be followed by completely dead.
I sent if off to North Hollywood Speedometer for repair. The technician said they replaced the circuit board. He said the gears were fine.
It's worked fine for about six months but is now acting up again.
Any ideas why the problem would reoccur?
The speed sensor was replaced a month before the speedometer repair.
Banned
Joined: Oct 2011
Posts: 5,464
Likes: 31
From: Oregon
Mine did (is doing) this.
It began with a wobble in the speedometer while driving, then to the stays at zero before suddenly begin working, to be followed by completely dead.
I sent if off to North Hollywood Speedometer for repair. The technician said they replaced the circuit board. He said the gears were fine.
It's worked fine for about six months but is now acting up again.
Any ideas why the problem would reoccur?
The speed sensor was replaced a month before the speedometer repair.
It began with a wobble in the speedometer while driving, then to the stays at zero before suddenly begin working, to be followed by completely dead.
I sent if off to North Hollywood Speedometer for repair. The technician said they replaced the circuit board. He said the gears were fine.
It's worked fine for about six months but is now acting up again.
Any ideas why the problem would reoccur?
The speed sensor was replaced a month before the speedometer repair.
I'd give them a call.
Technical Guru
Rennlist Member
Rennlist Member
Joined: May 2002
Posts: 8,138
Likes: 122
From: USVI
Pull the speedometer and disconnect the wiring harness from it. Then take a look at the pins on the back of the speedometer. Are they mirror shiny or dull grey? You can clean them up with a pencil eraser (and then if you want, rub down with a contact cleaner like DeOxit, just don't rely entirely on the contact cleaner to fix this...) Our 993s are coming up on 20 years of age which is more than enough time for tarnish to accumulate on the pins causing all sorts of sporadic issues.
Instructor
Joined: Apr 2011
Posts: 122
Likes: 1
From: Alexandria, VA
Update:
My mechanic found an intermittent faulty ground on the connection to the speedometer.
He corrected the ground and appears to have solved the problem.
So far so good.
My mechanic found an intermittent faulty ground on the connection to the speedometer.
He corrected the ground and appears to have solved the problem.
So far so good.
Last edited by Jeff U; Jun 15, 2015 at 08:59 PM.
