ISOA Tech Tips - 2002

Last updated February 9, 2005

The tech articles on this web site are written with the understanding that you have some mechanical and/or electrical knowledge, and that you know and assume the risks and responsibilities involved in working on your own car. If you decide to make a modification to your car based upon one of these articles, you assume total responsibility and risk for those modifications. In no event will ISOA or any of its directors or officers be liable for any direct, indirect, incidental, or consequential damages arising out of your making modifications to your vehicle based upon the contents of an article provided in this web site. It's your car, and it can affect the health and safety of yourself and others - work and drive safely and wisely! To put it bluntly, if you don't know what you're doing under the hood, then you shouldn't be there.

Quick Index

• Fuses - The Wrong One Will Burn Ya
• Fix Your Blinkers
• Repairing a Cubbie Box Bracket - also available as a 101kB .pdf file
• What's the Hub-bub About? - parts list for rebuilding your IRS hubs December 3, 2002
• Tach-Braaapp - an electric tach installation on a TR6 December 3, 2002

Since the ISOA Snic Braaapp article enhanced by Joe Pawlak and the subsequent reprint of it in the April 2002 Anniversary Edition of the Stag News, there has been quite a bit of discussion about what constitutes "proper" fuses for our Stags and Little British Cars (LBC's). I hope to do a bit of definition and correction from that previous article, and simplify, if that is possible, what actually is a proper fuse to use, where to locate them, and how to identify them.

CORRECTION / Clarification:
In the first article, I referenced IEC 5mm x 20mm fuses. Although these are IEC fuses with the correct interrupt ratings for your car, they will not fit in your fuse holder as they are too short. You need a longer fuse, more like 6.5mm x 29mm measurements, or about 1.125 inch long and up to 0.25 inch diameter. BUT, Size is not the only requirement! DO NOT JUST PUT A UL/CSA AGC style fuse in your LBC. Like the title of that article stated, the wrong one will burn ya, or your car. More on this in this article.

The first article issues:
To sum the information that was printed in the first article, the fuses supplied from Triumph were built to conform to British Standards (BS) for wire protection, NOT standards in the USA commonly known as UL/CSA for Underwriters Laboratories / Canadian Standards Association. British Standard Fuses basically conform to European Electrical Standards commonly known as International Electrotechnical Commission (IEC) Standards.

These standards organizations all have different ways of specifying the fuses that are used in their respective parts of the globe, mainly because the wires the fuses are designed to protect are not the same physical size in the size and composition of the wire; or the size, composition and type of the insulation actually covering the wire. As an example, BS wire might be 0.1 mm of wire cross section measurement where UL wire might be 0.1 inch of wire cross section. You should know that a millimeter and an inch are not the same units, so the protecting device (fuse) needs to be designed for the differences.

Lost? Well unless you are an Electrical Engineer or technician, do not feel bad. After all, this is a science, an electrical science that people go to the university then gain experience for a good part of their life before mastering.

Tell me SOMETHING I can Understand please!
Some electrical basics 101: Current is energy measured in units called amperes or amps. This energy translates into heat when it "flows" hence the word "current". Remember that current is energy and translates into heat. I won't go into volts, loads or resistance, but you do need to know that volts are what gives the current the ability to flow. The more volts, the more ability or potential for current flow and the potential for more heat. Lets stop there.

Lets see if I can get this fuse thing to a simplification of the base problem and parts. There are a myriad of fuses out there that will physically fit in your LBC.

The little glass fuse with the paper inside:
Originally, your Triumph was supplied with a small fuse with metal ends and a glass cylinder center piece manufactured by Lucas Electric. Inside the glass was a tiny piece of paper that said "Lucas" with two number ratings of the fuse, and a wire to carry the current. It measured approximately 1.125 inch long and about 0.20 inch in diameter.

The first number rating right after "LUCAS" is the number in amperes (current) that the fuse will "open", "blow" or "interrupt the current". In the paper fuse examples here above, you see a LUCAS 50A a LUCAS 35A, two no brand 35 amp with paper inside, a Clear Hooters 25 amp. The second rating in the Lucas style fuse was a number followed by the words "amps continuous" In the picture examples, you see 25 amps continuous, 17.5 amps continuous. This is the real important information, because that is the current rating of the normal use of the wire going to your Triumph accessories like your headlights, radio and instruments. Remember this second point for a few minutes.

Fuses of the Colonists:
Back in the USA, we have the AGC / MDL little glass fuse with no paper inside (LittleFuse, Cooper/Bussman, what-EVER!), and a 35A AGC stamped on the side of the metal cap.

So, the first time something in your Triumph wiring went bad, it blew a fuse and maybe you had no instrument lights or tail lights, or headlights, or radio. Commonly, you may have stopped by an automotive supply store like PEP Boys with the blown fuse in your hand and the counter person gave you a box of these AGC fuses with the same rating as the bigger number printed on the Lucas fuse paper. If that happened to be 35A, they gave you an AGC 35 fuse to put in its place. After all, it looks like it fits in the clips, and the numbers are the same, so okay, you buy it. It is only $1.00 for the box anyway. This was the first mistake, because remember, USA fuses are designed to UL/CSA specifications. They protect DIFFERENT size wire, wire your LBC does not have in it. Remember this second point for a few more minutes.

Pardon me but don't "interrupt" me while I am working!!
Okay, so now you have power again to your lights, radio, etc and drive happily down the road. Next you start to smell plastic burning. If you were wise, you immediately stopped the car, turned off the ignition, jumped out and disconnected the battery ... right!

More probably, you kept driving, and your wiring ended up doing the job the fuse was supposed to do, that was "interrupt" the circuit, and your lights went out again. If you were even more unfortunate, the wire was in an area where there was additional things to catch fire, and you noticed flames and or heavy smoke. "Damn Lucas wiring" you screamed disgustedly and you ran for some means to put the fire out.

So why did this happen?
Well, remember the second point that the Lucas fuse we used as an example was a 17.5 amps continuous / 35 A. The Lucas fuse would carry those 17.5 amps all day long, and if the current exceeded 17.5 amps approaching 35 amps, it would "open" "blow" or "interrupt" the current flow to protect the wiring so it could not exceed 35 amps.

And remember the third point that you replaced the fuse with an American UL/CSA AGC 35A fuse? Well, that little fuse was working away, doing exactly what it was designed for, allowing up to35 amps, (and a little more like even 10-20% more) through the wire in your LBC, the very same wire that is not supposed to carry that 35 amps.

Now remember that current flow translates into heat, and the more current the more heat? That is why the wires melted or a fire started, too much current allowed through the wire.

The Right Stuff:
First, only buy fuses that are manufactured in England or Germany (Bosch), and only buy them from suppliers who buy them from England or Germany. This is the only way you be 99% sure that you have the proper fuse for your car. Do NOT use UL/CSA AGC/MDL style fuses in your car EVEN IF you know how to properly size them to protect the wire in your LBC. WHY? Because the person you SELL the car to may not know how to properly size the fuses, and may just end up making the AGC error most people make in their cars. This can also happen if you take your car for service and the mechanic errors with the incorrect fuse.

Where to buy the Right Fuses:
For starts, try British Wiring, Inc., 20449 Ithaca, Olympia Fields, Illinois 60461. Phone / Fax (708) 481-9050. These folks buy their fuses from the UK and know that you must use IEC rated fuses for your British wiring. If you source your fuses from other British Parts suppliers in the USA, ASK THEM WHERE THEY GET THEIR FUSES!! Also, you can get them from the UK, James Paddocks is our chosen supplier for Stag parts of all kinds.

Gotta Keep 'em S-e-p-a-r-a-t-e-d:
When you buy your fuses for your LBC, clearly mark them on the container that they are UK style IEC fuses for use in your car. Do your inventory, toss out any AGC style fuses, or those you do not know the source.

I hope this clears up some of the confusion from the last article and helps keep your LBC from being a burned pile of ash on the side of the road.

By: Glenn Merrell
Stag Owner & Enthusiast

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Triumph turn signal flashers are heat activated switches. Activating the turn signal switch allows an electric current to flow through a strip of metal in the flasher module which acts like a heating element. As the metal strip heats up it bends and disconnects the circuit. With the circuit disconnected it begins to cool down. Once it cools down it returns to its original shape and restores the current flow, repeating the cycle. This series of hot/cold cycles makes your signal lamps go on and off.

The higher the voltage across the heating element the faster the metal strip will heat up. A dying lamp or a bad connection somewhere in the circuit will cause the voltage to drop and the flashers will start to cycle very slowly or remain on all the time. The left and right circuits share a single flasher module. If your right turn signal works fine but your left turn signal blinks very slowly then you probably have a bad bulb or a bad connection somewhere in the wiring for the left side. If both circuits fail then problem is either in the portion of the circuit that is common to both sides or the flasher module itself is going bad. Sometimes a bulb will create a short circuit when it fails. A short circuit can cause a much faster blink rate and will not always blow the fuse.

My flasher modules were failing about every six months. The new modules all seemed to come from Asia and they were not of the same quality as the original Lucas flashers. I don't know if they're more susceptible to vibration than the old ones or if the metal strips are weaker and are failing after a certain number of cycles.

You should spend the time to replace old lamps and clean the electrical contacts but flasher modules will still fail eventually. The permanent solution to the problem is an electronic flasher module. Electronic flasher modules cost between $10 and $15 at most auto parts stores. They use a solid state timer to regulate the flash cycle and are not affected by low voltage. Flasher modules come with either 2 or 3 terminals. My TR6 uses a 2 terminal module located in the passenger foot well. A second 2 terminal module near the fuse box is used for the hazard flashers and can also be replaced with an electronic module. Other Triumphs uses 3 terminal modules so check yours before you head to Auto Zone. The only downside to using an electronic flasher is your blink rate will no longer change when there's a problem in the circuit. If you have an electronic module installed you should periodically check all the signal lamps to make sure they are working, but you do that anyway, right?

By: Erik "Iceman" Quackenbush

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Note - this ISOA Tech Tip is also available as a 101kB .pdf file.

I've written many a segment on major restorations but sometimes it's the little things that matter just as much as a frame rebuild or differential renewal. More often than not we are coming across small parts that have broken or worn and are made out of the rare material called "unobtainium". Sometimes you can get lucky and find a good used part, but many times they are broken or are in the process of failing in the same way. While it may be insignificant, the glove box or "cubbie" bracket is one of those items that can not be acquired and all of the used ones are broken in a similar way. While this bracket is specific to the Stag, I have seen similar items in other TR's.

This plastic bracket seems to always break at the mounting point that attaches inside the glove box area. I do not have the ability to cast plastic, but I do have a collection of tools to fabricate a similar piece using some common scrap sheet metal.

In the scrap box I had some stock that was about 0.07" thick which is around 15-16 gauge. I traced out the rough shape of the bracket mount and cut the stock. Since I don't have anything to "precisely" cut that thickness, I used a flat file to shape the mounting plate to the size I needed. From there I measured the two center points of the original mounting holes and marked those on the plate. A third center hole was placed exactly in the center of this plate.

For the two mounting holes I used a 11/64" bit. I then followed up with a larger bit to slightly counter sink the holes. This makes for a nicer look when using the original countersunk mounting screws. The center hole was drilled out using a 7/64" bit. The plate was then flipped and this hole was countersunk on the opposite side of the two mounting holes. Finally the plate was cleaned up, degreased, primered and painted with a semi-gloss black paint that matched the original bracket.

The next step was to trim off what was left of the mounting plate from the guide stud on the bracket itself. A little carving and some finish work with a fine file did the job. On a couple of the brackets, a portion of the inside of the stud is hollow. I mixed up some epoxy (or JB weld) and filled the void. This was allowed to dry and then was drilled to hold a small screw. Drill through the filler and into the plastic of the stud. Be careful not to come out the top! Look in your screw parts bin for a small countersunk screw that is not too long or too short. Enough that it will bite into the epoxy and up into a portion of the plastic of the stud. The size is of your choice, so use your better judgement. There is no need to spend money on the components for this little project.

All that is left is to fit the painted plate to the bottom of the stud. The countersunk center hole of the plate will allow the screw to fit flush with the plate and fit nicely when attached to the glove box. Use the two original screws to mount the bracket and that's it. Looks pretty nice and is better than a piece of wire holding the glove box door from flipping down.

By: Joe "Stagmeister" Pawlak

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If you’re planning on rebuilding your TR4A IRS / TR250 / TR6 / Stag / 2000 IRS hubs during the winter, you may want to start ordering the parts now so you’ll have them when you’re ready to do the job. ISOA has the hub tool needed to separate the drive flange from the hub, but you’ll need to supply the following parts:

Triumph   Description     Quantity  TRF Price   Moss Price
Part                       per hub  (from 2002  (from Moss website)
Number                              price list)

GHS 131  Inner Grease Seal    1     $  2.95     $  2.95
GHS 133  Outer Grease Seal    1     $  2.95     $  3.20
138272   Collapsible Spacer   1     $  2.95     $  2.95
139057   Locking Plate        1     $  2.50     $  2.75
           (Tab Washer)
GHB 101  Inner Bearing &      1     $  7.95     $  7.50
           Race Assembly
GHB 265  Outer Bearing &      1     $ 19.95     $ 14.95
           Race Assembly

In addition, if your hub has a nyloc nut instead of a castellated nut & cotter key, you’ll need to replace the nyloc nut since they should never be reused:

138563    Nyloc Hub Nut       1     $  4.95     $  2.95

You may also want to replace the wheel studs while you’ve got everything disassembled. Note that wire wheel adapters use shorter studs than are used with steel wheels:

132317    Wheel Stud for      4     $  2.95     $  2.95
            disc wheels
142799    Wheel Stud for      4     $  3.95     $  3.90
            wire wheel
            adapters

While the seals, spacer and locking plate may be unique to Triumphs and must be purchased through Triumph parts vendors like TRF, Moss, Victoria British, etc., the bearings are not. The bearings and races can be purchased at your local Berry Bearing / Motion Industries branch location if you can’t get them through your normal Triumph parts vendor. Use the following Timken numbers when specifying the inner and outer bearings and races:

Timken P/N       Description  Quantity  Motion Industries
                              per hub   list price (2001)
LM 29749 (cone)  Outer bearing   1       $ 10.30
LM 29710 (cup)   Outer race      1       $  7.23
L 44649 (cone)   Inner bearing   1       $  7.31
L 44610 (cup)    Inner race      1       $  3.09

Your prices may vary for these bearings. You may want to check with your industrial parts buyer at work to see if they can get them for you at a better price.

By: Tim "Toolman" Buja

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Something was just not correct with the original factory tachometer (or rev counter as they say on the other side of the pond). In conversation with other ISOA TR6 owners with non-overdrive TR6’s indicated that at highway cruising speed (60MPH) the tachometer on their car indicated about 3100 RPM’s. The tachometer on my TR6 was reading about 4100 RPM’s. If this is correct, my engine would have blown up years ago.

Hooking up my multimeter with a tachometer attachment confirmed my suspicions. The tachometer on my TR6 was off by about 1000rpm . At idle it was fine but as the revs increased the less accurate it was. The TR6 has a cable drive tachometer so how it could be so far off, I do not know. It must be that the tachometer itself is internally worn out.

A quick search on EBAY found a used TR6 tachometer that sold for about $70.00. But would it be any better than what I already had. What I did find was a SUN Mini-Tach from Summit Racing for about $35.00. It was an electric model with a 2-5/8 inch body.

If you remove the drivers side vent (do they really work anyways?) the opening is 2-1/2 inches. You can open this up to accommodate the Mini-Tach and mount it flush or angle it and leave the body partially exposed like I did. I did not want to take a file or hacksaw to the metal dash support. The SUN Mini-Tach has a switch to work on 4,6 or 8 cyl cars and was really easy to hookup. It even lights up with my dash lights. The bottom line is that it is much more accurate than the original tachometer. I left the original tachometer in place still hooked up for originality but with the engine at speed side by side you can really see the difference.

By Ed Krakowiak

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