So.... anybody ready to start talking about alternative gauges for the FGT?

[Fubar]

The problem with the Optima and Odyssey (any other dry cell) batteries is that they can show a "good" voltage reading but lack the amperage to back it up. I'm not sure if this affects the chargers ability to determine correct charge parameters or not. I guessing that Shelby is right and the battery plays the biggest roll in gauge failure.

I have inspected a few gauges and found no mechanical or obvious electronic failure (the circuit board is not labeled so individual components could not be tested). It's a weird problem but I suspect replacement gauges would be a pretty big PIA. You would have to run wiring to all of the sensors for analog gauges or figure out a way to decode the CANbus. I would guess that Ray's people have already done that for the MoTec but I don't think they are using the stock gauge cluster anymore.

 

[Kayvan]

Sold 300 GTs

That's epic

 

[GT35065]

Shelby, thanks that is somewhat reassuring. Mine did have a battery that was drained to zero at one point a couple years ago. I had the factory trickle charger on the car, but it was mysteriously unplugged in my absence. Even though the original battery recharged and seemed to hold a charge, I replaced it with the Die Hard. Should have said the Die Hard is manufactured by Odyssey, not Optima in previous post.

A battery going dead is no excuse for failing guages, but so far that could be the link.

 

[hollywoodstunts]

Shelby, selling 300 GT's is epic. 10 out of 300, if my math is correct, is 3.3%.

When I spoke to a rep from Autometer, they said their failure rate is <.5%. So by Autometer's own standards, you have experienced a 5x greater failure rate than what Autometer allows. Again, that is if my math is correct. Since I get paid to jump off buildings on fire, there's a really good chance my math might be off.

But the question is, how many gauges have you replaced in other exotics?

I've never had a gauge failure in any vehicle I've ever owned, car or motorcycle. I love my GT, but I have two light-weight door stops manufactured by Autometer.

 

[Beach-GT]

There is a switch that goes on the Plus battery terminal and has a place for the cable to attach. A screw clamps two plates together to be the switch. Open the plates and the battery is disconnected from the car. I've seen this for the old round post battery. I'm wondering if it is a good idea to not have the car electronics maintained at the standby level though. Seems like a shocker to start from zero each time and then the car computer has to go thru the maping process again too. I'm not sure that would have any life lengthening affect on the gauges. I'm thinking about disconnecting the gauges altogether so they don't die and plugging in a dash-dac or something into the OBD that has all the gauges we need. Probably does not have a speedometer though.

 

[HHGT]

There is a switch that goes on the Plus battery terminal and has a place for the cable to attach. A screw clamps two plates together to be the switch. Open the plates and the battery is disconnected from the car. I've seen this for the old round post battery. I'm wondering if it is a good idea to not have the car electronics maintained at the standby level though. Seems like a shocker to start from zero each time and then the car computer has to go thru the maping process again too. I'm not sure that would have any life lengthening affect on the gauges. I'm thinking about disconnecting the gauges altogether so they don't die and plugging in a dash-dac or something into the OBD that has all the gauges we need. Probably does not have a speedometer though.

We can keep the tender on for safe measure and unscrew the clamp for safety. One would have to be disciplined to check the voltage of the battery before re-screwing the clamp back on. Thanks fo rthe info.

 

[mardyn]

That dash-daq device looks like an interesting solution.... if (big IF) it can interface with the GT's
processor.

The idea that our GT's gauge failure issues is a minor, isolated incident is absurd to me. If they had this kind of failure rate across
one of the major car lines, Ford would be issuing a safety recall right now.

Again, I'll mention I'm not seeking any kind of warranty parts or service for free from anybody... I just want some help (from the OEM level) to get my
Ford GT SUPERCAR(??) back in usable condition...

mardyn

 

[SteveA]

I'm not sure about the low battery theory. My '05 has never had the battery go flat dead, always on a tender, always started or driven at least once a month and when the battery first began showing signs of getting weak it was replaced with another factory battery. Result is I have had 2 fuel gauges fail. My second is a '06 which is in storage, has had the battery go flat 6 to 8 times, always charged back up to life while still hooked up, never been on a tender (until 4 months ago), had a complete dumbass install it's third new battery "BACKWARDS" (pos to neg & neg to pos) which I'm told arced like a s.o.b. blowing out the main in-line fuse link, plus 5 additional fuses (Kendall can verify). Result, not a single gauge issue. I have owned over 50 cars in my life and have only had one other car have a gauge failure, a '69 TR6 lost a Volt gauge. Like a few have stated I'm just driving with the dead gauge and guessing on my fuel level and happy it's not the oil or temp gauge.

 

[KJRGT]

I'm not sure about the low battery theory. My '05 has never had the battery go flat dead, always on a tender, always started or driven at least once a month and when the battery first began showing signs of getting weak it was replaced with another factory battery. Result is I have had 2 fuel gauges fail. My second is a '06 which is in storage, has had the battery go flat 6 to 8 times, always charged back up to life while still hooked up, never been on a tender (until 4 months ago), had a complete dumbass install it's third new battery "BACKWARDS" (pos to neg & neg to pos) which I'm told arced like a s.o.b. blowing out the main in-line fuse link, plus 5 additional fuses (Kendall can verify). Result, not a single gauge issue. I have owned over 50 cars in my life and have only had one other car have a gauge failure, a '69 TR6 lost a Volt gauge. Like a few have stated I'm just driving with the dead gauge and guessing on my fuel level and happy it's not the oil or temp gauge.

SteveA, like you my 05 has the original battery, but has never shown signs of getting weak, I think. What were those signs?
It's driven every 2-3 weeks and with 17,800 mi., never experienced a single gauge issue.

 

[ViperJoe]

As previously posted, about a year ago my fuel gauge failed and had to be replaced. Then about 6 months ago my volt meter failed. I've resisted replacing the volt meter because of the uncertainty as to what is actually causing the failures and hence the possibility of a recurrence. All this talk of battery options, chargers, etc., etc., etc., is plain shooting blindly in the dark. I've owned a hundred cars and never had a single gauge failure ..... and it's not my job to figure out what the problem is ..... it's Ford's job. The GT is arguable the greatest car ever produced in America and beyond and to say I'm disappointed is a gross understatement. As with many of you, my life is far to complicated and cramped to be forced to solve a problem that plain shouldn't exist. As I ponder the possibility of moving on, I realize the (ridiculously over-priced) gauge will need to be replaced regardless (I'll just hope that it holds up for a while). Who is the best source for a replacement gauge? Kendall? Rant not over!

 

[JAYGT]

My gas gauge acted up yesterday after i fueled up and started the car (stayed at quarter of a tank) turned off the the car and upon restart all was good again, thank god. I already replaced all my toggle switches on the dash except the hazarad because the led lights stopped working! Reminds me of the old lucas electronics on the british cars.........

 

[nota4re]

The best - but far from perfect advice that I would recommend to all: Replace your OEM battery with the Sears Platinum at the earliest opportunity. When not in use for longer periods of time (3 weeks or more between drives), keep a battery tender on the battery. With this done, replace any/all failed gauges and be happy. Although not (yet) statistically significant, I'm not aware of any gauge failures on a car using a "conventional" battery. Regarding the gauge replacement, I could walk you through the process or if you prefer my ace GT mechanic could fly to your location and do the replacement in your garage. We can source the gauges, no problem. I too am frustrated with the gauge scenario, but remember that probably 90%+ of the cars have not experienced a failure. With the above steps taken, I think you have a great chance of leaving the gauge problem behind you.

 

[dbk]

I knew he was collecting them, I just never saw any proclamation that Ford itself was involved.

What else would I be doing with them? :confused

I took the gauges, physically put them in the hands of the Ford GT Program Manager, and they were subsequently sent to Autometer for diagnosis. Wish I had more. From the way it sounds, there must be thousands of them. I've only managed to get ahold of what, 3?

 

[ViperJoe]

I've only managed to get ahold of what, 3?

That is disappointing and somewhat perplexing. I wll replace my voltmeter and sent it to you ASAP.

 

[SteveA]

What else would I be doing with them? :confused

I took the gauges, physically put them in the hands of the Ford GT Program Manager, and they were subsequently sent to Autometer for diagnosis. Wish I had more. From the way it sounds, there must be thousands of them. I've only managed to get ahold of what, 3?

That just kills me that you only have received 3 Dave. My first fuel gauge was replaced by the dealer and the second is still in the dash to be replaced at the rally and you will receive that one Dave.

Fellow GT owners, let's get these bad gauges to Dave asap before the problem is dismissed as a very minor issue by Ford and we're ignored!

 

[nota4re]

Quite a long time ago, I stated that my hypothesis was that the gauge problem was linked to the type of battery (Optima) used in the GT. In particular, I have noticed OEM batteries that were quite happy to "live" at voltages lower than the conventional lead-acid battery types. In particular, we have seen cars that cranked/started almost instantly and where the battery in these cars measured in the ~10.5V range... yet you'd never know there was a problem.

Further, we know as a fact that a low voltage condition may occasionally cause one or more gauges to not be initialized properly and to remain off for that ignition-on duration. Finally, we have Shelby's observation that when he has seen cars with gauge failures, he can almost always link this to car which have had a low battery. So, I guess I have a question to any EE-knowledgeable members.

Let's say that a particular gauge wants to consume a certain amount of electrical power (P). We know that P = VI. Let's say at key-on (before cranking and engine-on), the gauge control module and the gauges "see" V=10 volts. So, the first (naive) question is if the current will be higher than expected because the voltage is lower than expected? If so, can this be harmful to electronics that may have been designed to "see" 12v? The second (naive) question is what happens to these electronics - who could be mid-stream negotiating with each other, and the voltage suddenly jumps to 13.8v as the car starts and the alternator instantly kicks on? This is a scenario that I think happens a lot to our cars with the Optima battery.

 

[2112]

What else would I be doing with them? :confused

You seem to have a lot of connections regarding the GT including the GT guys. Without a direct statement that the factory was looking into it, I chose not to assume that is was indeed, the factory. :bored

 

[dbk]

I mentioned it in multiple prior threads.

First, the primary thing that anyone can do to help the gauge issue get resolved is to get their gauges to me so I can give them to SVT. If you'd rather, I can get an address from SVT to have you send it direct to Allen Park, though if they come to me, I can just walk across the street to Jamal's house and physically put it in his hands to ensure he gets it. They have not received a suitable amount of gauges at this point. When we've tried to corral some in the past, we haven't had much success getting them.

So please, if you have a bad gauge, PM me and I will get with you to get the gauges into their hands.

I need more gauges to give to SVT. I gave them the ones I got from Shelby, but out of all the gauges that are supposed to have failed otherwise, they've only been handed one. Can't make a diagnosis without having a larger sample to look at, although there is already a theory. So if you've got a bad gauge laying around, please send me a PM so I can get it from you and hand it off to SVT.

At this stage, I'm beginning to think that either a) the problem isn't nearly as widespread as some people hypothesize or b) some people are more inclined to live with it for an opportunity to complain on the internet. I would be extremely bummed if I had a gauge go bad (like I was when my halfshaft bolts broke at a busy intersection at 4 p.m), but on a 5 year old out of warranty car, unless people attempt to be more proactive getting it fixed, it never will. Or at least if not fixed, diagnosed. I've heard a couple guys rumbling "oh well I know this guy at Ford and he said..." Forget that. This forum has a good relationship directly with the guys at SVT that built the car. They frequent our events. They answer any question about the car they can when they can. We're trying to get traction with the source of the car, but at this point, we don't seem all that credible when I harass them and say "tons of gauges are bad" and they say "give us some" but after months of prodding I can only produce 3!

 

[SteveA]

SteveA, like you my 05 has the original battery, but has never shown signs of getting weak, I think. What were those signs?
It's driven every 2-3 weeks and with 17,800 mi., never experienced a single gauge issue.

The battery was 5+ years old and I had noticed it was cycling on and off more often and staying on longer over the winter. Not very scientific I know, but I just didn't see any reason to try and push it another season.

 

[FGT1987]

Hi Kendall, first a disclaimer - I don’t have a clue how car gauges work but I do have many years of experience designing circuit boards so for what it’s worth I’ll try to answer your questions.

To your first question about the power draw of a gauge I think the way to look at it is: each gauge would have a certain amount of resistance, which is constant and does not change with fluctuations of the voltage supplied, so from ohms law V = I x R and R being constant then the current draw from the gauge would actually be less when the supply voltage dropped R = V/I and consequently from your equation P = V x I the power would also be less.

As far as I can tell there would be 2 parts, the first being the electromechanical part i.e. the movement of the gauge itself and the second part would be the circuitry to interpret the input signal and drive the gauge mechanism accordingly. I can’t really comment on the electromechanical part but from my experience in designing circuits with microprocessors I have never seen a chip fail from too little voltage, what would normally happen as the voltage falls out of spec the chip would start to act erratically until the voltage got so low it would just cease to run – but, with a proper reset (power down then up) and correct voltage supplied the processor will always start back up.

In my experience the vast majority of failures are caused by overvoltage such as voltage spikes caused by the power supply, or static electricity, which can come from numerous sources.

The chips that are used in the auto industry tend to be very robust meaning they typically have all sorts of protection built in, as the electrical environment of an auto is considered very harsh.

Does anyone know exactly what part of the gauge is failing? If anyone has repaired one by replacing circuitry then that would be a good start in working backwards from there to determine the exact cause of failure.

Anyway, there are a lot of more knowledgeable people on this topic then myself – hopefully someone will figure it out.