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TR2/3/3A Short on electricity, not short in.

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Crankshaft

Crankshaft

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As I followed the Tr4 thread re: "gauge nightmare", it reminds me of a question I've had. If I have the head lights on, there is not enough power to activate the turn signal flasher until I rev to about 1200 to 1400 rpms. Would that indicate an in-adequate generator, battery, flasher or something else? My headlights are pretty dim at idle speed.
 
That's one of those "weakest link" questions. It is normal for the system voltage to drop at idle, because the generator cannot produce any output at such low rpm. So the engine, headlights, etc. are running on the battery instead of the generator. The voltage at the battery drops fairly quickly from around 14 volts down to 12.6 or so (and then slowly goes down even further).

It's also normal for the flasher to be sensitive to the amount of current through it. This is supposed to be a safety feature, so you can tell from the light on the dash when one of the turn signal bulbs is burned out. But it seems like, as the thermal flashers get old, they need more current to continue operating. Also, as the turn signal bulbs age, they draw less current (and produce less light).

So, could be the flasher, could be the battery, could be the wiring, could be the bulbs, or even the turn switch. Jonmac had this problem only on one side, which he eventually traced to corrosion inside the wire insulation! About the only thing not suspect is the generator (as it isn't supposed to work at idle anyway).

I got tired of chasing the problem on my TR3A, and just switched to a "heavy duty" flasher, which is not as sensitive to load current. I couldn't find a thermal flasher at FLAPS that would work properly, so I bought an "electronic" Tridon EL-13. It works great, but of course does not look original. One caution, though, the EL-13 plastic case is not very strong. If you use a clip to mount it, make sure the clip is not too tight. The case on my first one eventually broke from the pressure. But the second one is still working great (now on the TR3).
 
As always, I agree with Randall, but I would like to add my two cents. You "could" have any of the problems listed. You could "solve the problem" by replacing all the components suggested. You might even be able to find a poor ground connection that would rectify the issue. Or, you could ignore it and know it's not going to go away, but will never be more of a problem than you let it be.

I have a brand new battery, properly working generator and regulator, new wiring harness, with all new fixtures and bulbs, new flasher unit, individual grounds at every light fixture, and I can't tell you if my flasher slows down at 900rpm, or not. The reason is I have the idle set to over 1,000rpms. This is just above where I have the regulator set to cut out. And even if I set the idle lower, and the flashers slowed down with the headlights on, I wouldn't worry about it. Perhaps if I drove only at night, or spent much time with the lights on in stop-n-go traffic with the turn signals flashing and the RPMs under 1200, I would consider another approach. But if you have a decent battery, and the generator is working, and you drive in 'normal' driving situations, I don't think you have a problem at all. The battery will discharge and recharge.

If anyone asks why your flasher slows down, tell then it's a special Lucas speed sensitive flasher.
 
TexasKnucklehead said:
As always, I agree with Randall
Click to expand...

Which causes me to reflect and ask--where can one man learn so much about Triumphs?

I had a friend who thought I knew a lot, and attributed it to my car breaking down so regularly that I seemed to face every auto related problem conceivable.

But Randall shames the best of us. I like to think Randall was a mechanic at British Leyland in the '60s, or the guy in the white coat in my TR Shop Manual.
 
KVH said:
I like to think Randall was a mechanic at British Leyland in the '60s, or the guy in the white coat in my TR Shop Manual.
Click to expand...
<blush>
No, no, nothing like that. It's a combination of a lot of things, really, starting with a long term love affair with the car, and driving a series of them for many years when I didn't have enough money to even think of taking it to a professional for repair; plus a life-long fascination with the underlying processes, materials and physics. I got pretty good at putting lawn mowers back together before I did my first car engine at 15 and my first TR3 engine at 19.

Part of it too is a willingness to type this stuff over and over. I'm a pretty good typist and my job is such that I get frequent breaks just long enough to answer a post or two. Lots of folks know far more about TRs than I do but don't have (or don't take) the time to respond. In many cases I am only repeating what I heard from them.
 
I, as many, sure do appreciate the advice I get from Randall (as well as a few others). A while back Moss maintained a forum and I would ask questions and always welcome the input received. However, I always waited for "Motor Bill" to give his input. Here and now I wait for Randall's take on a situation, except of course regarding body work. But I avoid body work like the plague.
 
I haven't been posting; just lurking. But I have saved lots of Randall's postings to use in the re-assembly of my TR3.
Thanks, Randall!
Bob
 
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