Gauge failure


RADGT

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Aug 31, 2006
858
Connecticut
Well, I have joined the club. Took longer than most. Car is always on a battery tender. Tach was working yesterday but today
nothing.

Stu
 
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FlagstaffGT

GT Owner
Mark II Lifetime
My speedometer crapped out on the way to the rally, came back for 1500 miles, and went south again late on the first track day. Similar to sending unit failure experienced earlier ( returning from Vegas Rally), will replace sender soon and will advise.
 

427Aggie

GT Owner
Mark IV Lifetime
Aug 18, 2005
885
Frisco, Tx
Send your gauges to Dave. They are having an issue getting enough because guys want to keep them.
 

texas mongrel

GT Owner
Mark II Lifetime
May 3, 2009
1,661
Houston Texas
Someone at the rally told me they finally think they know the cause of the failures- something to do with an internal clock inside the electronics of each gauge; if it loses power/ gets insufficient voltage it won't always reset, thus causing the failure. Don't know the accuracy of this, but hope its true 'cos at least then there'll be a fix for the problem
 

1418

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Nov 14, 2005
786
south FL
Unfortunately my first post in quite a while is to report that 1418 has lost use of the tach. too. I wish I could bring myself to use our aftermarket solution but like some others I'd like to keep it original. I'm going to wait and see if a fix is in the works before changing it out.

Manny
 

twobjshelbys

GT Owner
Jul 26, 2010
6,053
Las Vegas, NV
Someone at the rally told me they finally think they know the cause of the failures- something to do with an internal clock inside the electronics of each gauge; if it loses power/ gets insufficient voltage it won't always reset, thus causing the failure. Don't know the accuracy of this, but hope its true 'cos at least then there'll be a fix for the problem

A clock used by a digital circuit should be able to be reset when the power is totally removed. Has anyone with a gauge failure simply tried removing the battery for an extended period of time? Maybe the association with the battery change isn't the battery itself but the fact that the whole car was unpowered for a relatively long time (changing a battery takes say 10-15 minutes).
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
...(changing a battery takes say 10-15 minutes).

Yes, for those of you with a 2006 Shop Manual. I started doing mine based on the 2005 Manual, which wants you to remove the splitter and pull the battery out the bottom!!!!!!!!!! Fortunately, after a removing the splitter and a looking at the car, I opened up the 2006 Manual and yes, it can be done in that time. :frown
 

FlagstaffGT

GT Owner
Mark II Lifetime
I removed my battery cable for about 1/2 hour, reattached, and had the
same jumping speedometer. Will try the sending unit next.
 

twobjshelbys

GT Owner
Jul 26, 2010
6,053
Las Vegas, NV
I removed my battery cable for about 1/2 hour, reattached, and had the
same jumping speedometer. Will try the sending unit next.

Oh well, it was worth a try. One more obvious fix eliminated.
 

FlagstaffGT

GT Owner
Mark II Lifetime
Speedometer still jumping, but then went to zero AND odometer and trip meter went to dashes. Couple of miles, then stopped and turned off car. Odometer came back and speedo was jumping again. Waiting for sender unit ($35 bucks). Disconnected sender and will try a softish short to the gauge (through maybe a 3k r, I've seen capacitors in timing circuits take a long time to discharge). Will reconnect sender and if anything happens will advise.
 
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Waldo

GT Owner
Mark IV Lifetime
Sep 7, 2005
767
Fort Worth, TX
Has anyone with a gauge failure simply tried removing the battery for an extended period of time? Maybe the association with the battery change isn't the battery itself but the fact that the whole car was unpowered for a relatively long time (changing a battery takes say 10-15 minutes).
My speedometer quit working after my one-year old Optima had been disconnected for about a week.

The speedometer worked as it should...
I disconnected the negative terminal on the battery...
I tinkered with the car for a week...
I reconnected the negative terminal on the battery...
The speedometer never moved off of zero again.
 

FlagstaffGT

GT Owner
Mark II Lifetime
Dodged the gauge bullet again. $37 speedometer sender unit. 7 minute replacement, pulling the air box and once I realized the mounting bolt needed a hex key to remove it. Second replacement to date, 1st under warranty after two years.The head of the sensor was worn at a slight angle, wouldn't have thought it should actually have made any contact, guessing it being an inductive or magnetic pickup. BTW, odometer works off this sensor too. Got a very needed bath too after several thousand insect removals and a substantial Texas squall.
 

johncn

New member
Jan 24, 2017
4
Did your odometer ever stop working?
My speedometer does not work but my odometer is fine.
I don't think it would be the sending unit.
What do you think?
Thanks.
I would get a sending unit if there was a chance that that would fix the speedometer.
John
215 493-0540
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,177
The odometers do not fail. We will offer a repair service for tachs/speedos here shortly. Watch for a thread on the topic.
 

2112

Blue/white 06'
Mark II Lifetime
Subscribing
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
The odometers do not fail. We will offer a repair service for tachs/speedos here shortly. Watch for a thread on the topic.

What is the most common failure mode of the OEM gauges?
 

NorthwoodGT

GT Owner
Jun 12, 2009
1,215
Michigan
Did your odometer ever stop working?
My speedometer does not work but my odometer is fine.
I don't think it would be the sending unit.
What do you think?
Thanks.
I would get a sending unit if there was a chance that that would fix the speedometer.
John
215 493-0540
the odometers are a separate module in the gauge cluster and you don't ever want to have to purchase one of those!
 

SteveA

GT Owner/B.O.D
Mark IV Lifetime
Dec 13, 2005
3,694
Sandpoint Id
The odometers do not fail. We will offer a repair service for tachs/speedos here shortly. Watch for a thread on the topic.

That would be great news Kendall. Outstanding!
 

Dwhite

Member
I see spedometers and tachometers on Fords website as replacements for insane money. Why are these guages so expensive? just limited #s produced.
 

twobjshelbys

GT Owner
Jul 26, 2010
6,053
Las Vegas, NV
I see spedometers and tachometers on Fords website as replacements for insane money. Why are these guages so expensive? just limited #s produced.

Limited supply is part of it but you should read the whole gauge story. Just search gauges. If there is a weak points in the car it is gauges. Original style small gauges are available directly from autometer but they haven't do everything the larger ones. For the larger ones you choices are Ford or maybe this repair or to replace the whole set with speedhut