Malfunctioning SW Tach

[mgreene]

My SW tach in Unique COB9072 just all of the sudden started functioning incorrectly - it reads about 3000 rpm too high, and the pointer stays at 3000 when the car is turned off. Worked fine up until last week. Does this sound like a ground problem, or a problem with the tach itself?



Mike Greene

'66 GT-350H : '69 428SCJ Mach 1
'70 Boss 302 : '93 SVT Cobra
Unique 289 FIA (351C)

[427sc]

Mike - There are a number of us with similar problems with SW tachs. Check out a thread over in Club Cobra called Tach Accuracy Questions. The SW tachs seem to work OK for a time but eventually will start to read 'high', bobble, float, or just simply mis-read. I replaced a SW tach with a new SW only to have the same thing start a year or so later. No one seems to know exactly what causes this or how to fix it. I sent my tach to SW in El Paso for inspection/repair. I'll let you know what they found if anything. If you want to contact SW about your tach you can email them at rthibodeau@maximatech.com Len

[427sc]

Mike - There are a number of us with similar problems with SW tachs. Check out a thread over in Club Cobra called Tach Accuracy Questions. The SW tachs seem to work OK for a time but eventually will start to read 'high', bobble, float, or just simply mis-read. I replaced a SW tach with a new SW only to have the same thing start a year or so later. No one seems to know exactly what causes this or how to fix it. I sent my tach to SW in El Paso for inspection/repair. I'll let you know what they found if anything. If you want to contact SW about your tach you can email them at rthibodeau@maximatech.com Len

[mgreene]

Thanks, and yes, please let me know what they say. Are there other brands (Autometer, Smiths, VDO) that look similar but work better?

'66 GT-350H : '69 428SCJ Mach 1
'70 Boss 302 : '93 SVT Cobra
Unique 289 FIA (351C)

[mgreene]

Thanks, and yes, please let me know what they say. Are there other brands (Autometer, Smiths, VDO) that look similar but work better?

'66 GT-350H : '69 428SCJ Mach 1
'70 Boss 302 : '93 SVT Cobra
Unique 289 FIA (351C)

[clayfoushee]

Ditto what 427 said, but to add another data point, I talked to Maurice Weaver, who said he was having 50% failure rate with the SWs he's installed over the years. He also said he'd been fighting with them for years about fixing it.

My problem is sporadic, but I never do trust the reading. I'm counting on the 6K rev limiter to do it's job.

My tach also stops in the position it was reading when switching the car off. Try turning the key to the aux (left of off) position. On my car, that knocks it back down to 300rpm (equivalent to 0 on my tach).





Unique 9299, 427FE side oiler

[clayfoushee]

Ditto what 427 said, but to add another data point, I talked to Maurice Weaver, who said he was having 50% failure rate with the SWs he's installed over the years. He also said he'd been fighting with them for years about fixing it.

My problem is sporadic, but I never do trust the reading. I'm counting on the 6K rev limiter to do it's job.

My tach also stops in the position it was reading when switching the car off. Try turning the key to the aux (left of off) position. On my car, that knocks it back down to 300rpm (equivalent to 0 on my tach).





Unique 9299, 427FE side oiler

[mgreene]

Clay,

That's exactly what mine is doing now - when I turn the car off it reads the last RPM. When I turn the switch over to on, it goes back to around zero.

'66 GT-350H : '69 428SCJ Mach 1
'70 Boss 302 : '93 SVT Cobra
Unique 289 FIA (351C)

[mgreene]

Clay,

That's exactly what mine is doing now - when I turn the car off it reads the last RPM. When I turn the switch over to on, it goes back to around zero.

'66 GT-350H : '69 428SCJ Mach 1
'70 Boss 302 : '93 SVT Cobra
Unique 289 FIA (351C)

[Brent]

I heard a rumor that SW was going to replace the guts in this tach with the guts in their comp. tach and retain the current look?????????

OOOOOOOHHHH Alan.......Alan.....Alan....(-:

[Brent]

I heard a rumor that SW was going to replace the guts in this tach with the guts in their comp. tach and retain the current look?????????

OOOOOOOHHHH Alan.......Alan.....Alan....(-:

[427sc]

Mike (and others) - except for a red pointer, a #2499 Autometer is very similar in size and looks to a SW. I believe Autometer also markets two lines that replicates Smiths and SW, although I don't have any part numbers. Those two lines are made at their industrial facility in Utah. Perhaps someone here can dig up those part numbers for us. Len

[427sc]

Mike (and others) - except for a red pointer, a #2499 Autometer is very similar in size and looks to a SW. I believe Autometer also markets two lines that replicates Smiths and SW, although I don't have any part numbers. Those two lines are made at their industrial facility in Utah. Perhaps someone here can dig up those part numbers for us. Len

[pgermond]

In the "for what is worth category" - Alan provide me with Autometer gauges (car delivered in August) due to the problems with SW. The car isn't running yet, but the gauges (including reverse speedo) look good in the dash [^] I suppose time will tell [?]

Phil

427 Roadster, #4279436
Southern Automotive FE
Toploader

Roseville (N.Cal)

[pgermond]

In the "for what is worth category" - Alan provide me with Autometer gauges (car delivered in August) due to the problems with SW. The car isn't running yet, but the gauges (including reverse speedo) look good in the dash [^] I suppose time will tell [?]

Phil

427 Roadster, #4279436
Southern Automotive FE
Toploader

Roseville (N.Cal)

[clayfoushee]

The Weavers confirmed to me what Phil, 427SC, and others have said here, that the Autometers are more accurate, don't fail very often, and I'm thinking of switching too. Maurice Weaver also said that SW was planning to change the "guts" and retain the original SW face.

Right now, I'm just happy when the SW moves up and down in the proper direction with the engine RPMs. As I said before, I'm counting on my MSD with 6K rev limiter and my ear to keep my side-oiler from expelling it's innards.

Unique 9299, 427FE side oiler

[clayfoushee]

The Weavers confirmed to me what Phil, 427SC, and others have said here, that the Autometers are more accurate, don't fail very often, and I'm thinking of switching too. Maurice Weaver also said that SW was planning to change the "guts" and retain the original SW face.

Right now, I'm just happy when the SW moves up and down in the proper direction with the engine RPMs. As I said before, I'm counting on my MSD with 6K rev limiter and my ear to keep my side-oiler from expelling it's innards.

Unique 9299, 427FE side oiler

[WBofTN]

I too have tach bobble - thinkin of changing over to autometer - here
is what Autometer sent me.
WB

Here is a picture of the 427 series, Cobra, vintage style gauges. The
model #'s are:

201004 - 4" Tach. 8,000 RPM
201005 - 4" Speedo. 180 MPH
201006 - 2" Oil Press. 100 PSI
201007 - 2" Water Temp.
201008 - 2" Oil Temp.
201009 - 2" Voltmeter
201011 - 2" Fuel Level 240-33 Ohms
201975 - 2" Fuel Level 16-158 Ohms

Here are some phone numbers to three of our distributors:

Factory Five Racing, in Ma.: 508-291-3443
Tri State Motorsports, in Pa. : 717-859-5487
Finish Line, in Il. : 847-608-7800

http://www.uniquecobra.com/uploaded/wboftn/AMcobraCover.jpg

'93 Unique 427/351W/4sp

[WBofTN]

I too have tach bobble - thinkin of changing over to autometer - here
is what Autometer sent me.
WB

Here is a picture of the 427 series, Cobra, vintage style gauges. The
model #'s are:

201004 - 4" Tach. 8,000 RPM
201005 - 4" Speedo. 180 MPH
201006 - 2" Oil Press. 100 PSI
201007 - 2" Water Temp.
201008 - 2" Oil Temp.
201009 - 2" Voltmeter
201011 - 2" Fuel Level 240-33 Ohms
201975 - 2" Fuel Level 16-158 Ohms

Here are some phone numbers to three of our distributors:

Factory Five Racing, in Ma.: 508-291-3443
Tri State Motorsports, in Pa. : 717-859-5487
Finish Line, in Il. : 847-608-7800

http://www.uniquecobra.com/uploaded/wboftn/AMcobraCover.jpg

'93 Unique 427/351W/4sp

[pbrown]

Is it me or is that water temp guage have the wrong scale? Can one specify Autometer gauges in the Deluxe Palet Kit? I think that's the way I would go when I have enough pennies saved.

--Patrick

[pbrown]

Is it me or is that water temp guage have the wrong scale? Can one specify Autometer gauges in the Deluxe Palet Kit? I think that's the way I would go when I have enough pennies saved.

--Patrick

[clayfoushee]

Yep, the pic of that Autometer temp gauge shows a Celsius model....I'd be shocked if they didn't have a Fahrenheit version. Anyone, know off hand what a set of those cost?

Clay

Unique 9299, 427FE side oiler, top-loader (close), 3.31 rear

Annapolis, MD

[clayfoushee]

Yep, the pic of that Autometer temp gauge shows a Celsius model....I'd be shocked if they didn't have a Fahrenheit version. Anyone, know off hand what a set of those cost?

Clay

Unique 9299, 427FE side oiler, top-loader (close), 3.31 rear

Annapolis, MD

[pgermond]

You are correct - the oil and water temp read in "C", not "F". I don't know if they carry the "F" version, but I'm fine with the European version [^] - goes well with the reverse speedo. I got mine with my Deluxe Pallet Kit at the same price as the SW's.

Phil

427 Roadster, #4279436
Southern Automotive FE
Toploader

Roseville (N.Cal)

[pgermond]

You are correct - the oil and water temp read in "C", not "F". I don't know if they carry the "F" version, but I'm fine with the European version [^] - goes well with the reverse speedo. I got mine with my Deluxe Pallet Kit at the same price as the SW's.

Phil

427 Roadster, #4279436
Southern Automotive FE
Toploader

Roseville (N.Cal)

[427sc]

WB - Thanks for the information on the 'vintage' style Autometer gauges. If I were building a Cobra today I would definatly use these guages. They look great! You could also directly replace a Smith's set with these, hence the 'C' temp gauge instead of 'F'. However, they would not be a direct replacement for SW guages due to the size difference. I believe Enzo is also offering the Autometer set. Check his site for price. Does anyone know of a replacement guage set that replicates a SW set in size and looks? Thanks!

[427sc]

WB - Thanks for the information on the 'vintage' style Autometer gauges. If I were building a Cobra today I would definatly use these guages. They look great! You could also directly replace a Smith's set with these, hence the 'C' temp gauge instead of 'F'. However, they would not be a direct replacement for SW guages due to the size difference. I believe Enzo is also offering the Autometer set. Check his site for price. Does anyone know of a replacement guage set that replicates a SW set in size and looks? Thanks!

[Tony Radford]

It looks like one of the members over on ClubCobra purchased and installed the MSD Tach Adapter and solved his eratic tach behavior. I'll probably do the same thing during the winter. I started that thread after I spoke to MSD techline following my engine replacement.

427SC, Torch Red / white stripes
427 Windsor Stroker from Southern Automotive
Delicious example of Beauty + Power.

[Tony Radford]

It looks like one of the members over on ClubCobra purchased and installed the MSD Tach Adapter and solved his eratic tach behavior. I'll probably do the same thing during the winter. I started that thread after I spoke to MSD techline following my engine replacement.

427SC, Torch Red / white stripes
427 Windsor Stroker from Southern Automotive
Delicious example of Beauty + Power.

[clayfoushee]

Tony,

More details or a link to that ClubCobra site would be appreciated if you have them.

Clay

Unique 9299, 427FE side oiler, top-loader (close), 3.31 rear

Annapolis, MD

[clayfoushee]

Tony,

More details or a link to that ClubCobra site would be appreciated if you have them.

Clay

Unique 9299, 427FE side oiler, top-loader (close), 3.31 rear

Annapolis, MD

[Tony Radford]

Clay, go to www.clubcobra.com and look in the "shop talk" forum. There's a pretty long thread about this tach issue.

427SC, Torch Red / white stripes
427 Windsor Stroker from Southern Automotive
Delicious example of Beauty + Power.

[Tony Radford]

Clay, go to www.clubcobra.com and look in the "shop talk" forum. There's a pretty long thread about this tach issue.

427SC, Torch Red / white stripes
427 Windsor Stroker from Southern Automotive
Delicious example of Beauty + Power.