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Triumph TR6 - Voltage Stabilizer AGAIN?

72 Triumph TR6. As per the previous thread "Smoke From Under Dash"; I replaced the temperature sensor and the voltage stabilizer. Everything has been working great for the last week or so (2-300 miles). Today, I went for a drive (everything working) stopped for a minute and then started the car again and no temp gauge OR fuel gauge! No smoke, no smell, just nothing from the guages. A quick check with voltmeter showed 12.5 volts on "in" side and 0.01 volts on "out" (gauges) side of stabilizer. What the *$#@? I don't get it. How could it be bad again already? It takes full battery voltage (that's its job) so what could make it fry? I'm baffled and afraid to put in another at $18 each without knowing if there is something in the car causing the failure or did I just get a defective (doubtful) one? Any thoughts (or tests) would be appreciated.

Matthew
M Moment

Mike Petryschuk: In the "Smoke From Under Dash" thread, you made the comment:

"Maybe your alternator voltage control regulators are failing or failed and you are getting too high a voltage in the circuit. It would manifest itself when you are running at higher engine RPM as the alternator will be generating higher voltages and current. Is your volt meter reading on the car gauge consistent with the reading you get at the stabilizer?"

Of course, now I am wondering the same thing. Would you please clarify the last part where you said; "... Is your volt meter reading on the car gauge consistent with the reading you get at the stabilizer?" I'm not sure what you mean by that. My car only has a C+ D- AMPS type gauge.
Thanks, Matthew
M Moment

Hook up the volt meter to the Stab. and rev the motor to see what the in side is.
Are you sure you hooked it up right?
Somebody sells a solid state model.
DON KELLY

Hi Matthew

I thought your car may have had the voltage style meter not the amps meter (mine is an amps meter like yours)and I was wondering how you were measuring the voltage.

I assume you have a volt meter. Fire up the car, let it run for a while until the battery is charged again. Measure the voltage leading to the voltage stabilizer. See what it is. It should be 12 to 12.5

Rev the engine and while you have it revving at 3000 rpm or so take the measurement again.

The voltage should be 13 maybe 13.5 or less otherwise your voltage regulator may be kaput.

Mike
Michael Petryschuk

Hi Matthew

In thinking a little bit more about this, another indicator is your ammeter. When you are driving at higher speeds- engine RPM around 3000, is your ammeter showing a strong positive the whole time? If the regulator is working properly, it should show hi positive amps (C side) until the battery is recharged and then drop back down to showing a slight positive + charge at high RPM. A high +C all the time would indicate an over voltage/amperage condition in your circuit that may be exceeding your stabilizer design capability.

Let us know what you find.

Regards
Mike
Michael Petryschuk

Mike:
Just got back from a weekend holiday and yes, I'm using a voltmeter; will run the suggested tests tomorrow and let you know what I find.

Don:
If I'm not mistaken, you can't hook it up wrong but yes, I was careful hooking it up and as I metioned above, everything worked great for a week or so. The original was not solid state but the one I replaced it with was (from Moss).

Thanks guys, Matthew
M Moment

Yea you can.
Input on the wrong side. there is 3 connections
DON KELLY

Don:

Ok, thanks, I will make sure to look carefully before I disconnect this one; I would think hooking up backwards would cause an immediate failure as soon as it was powered however, not a week later.

Matthew
M Moment

Mike:

OK, I took some quick readings to see if I could get a handle on this issue. With the key / engine off: voltage across battery terminals is 12.8 volts. Start engine, running it anywhere from 1000-3000/4000 rpm, voltage across battery terminals is 14.67 volts. So, what do you think? Is that too much voltage output to an already strong battery? I would swear I saw in Bentley manual that as much as 15.5 volts was ok, but I could be wrong. Should I take the alternator to an electrics shop and have it bench tested? The voltage regulator is an intergral component of the alternator on these cars, right?
Thanks, Matthew
M Moment

Mine puts out 14.4 or so ,according to my computer read out.
DON KELLY

Don:

Thank you; so, if 14.67 is not an "off the charts" reading, where the heck do I go from here? I'm not replacing a $20 part with only the "hopes" that it won't go bad again.

Matthew
M Moment

Chiming in late but I agree that 14 and a half is OK and the stabilizer should be able to handle that.

I would measure the voltage at the stabilizer "in" terminal doing the same test just to confirm.

The regulator is in the alternator.

In the last thread I asked if the fuel gauge was working accurately but I don't recall if you confirmed this or not. I would ensure that the fuel tank float isn't faulty as it is in the same circuit. Does it intermittently go to full (or to empty)?

If this all checks out, I would look for frayed or cracked insulation on the wiring from the stabilizer to the fuel gauge and temp gauge. Insure there is no bare wire. Vibration may be causing any bare or exposed wire to contact a ground. Pay particular attention where the female connector spades connect to the wire.


Michael Petryschuk

What was the problem again?
DON KELLY

Well here is an update of the current situation. Morris at West Valley Gauges suggested that when I install the new stabilizer, I should create a new "circuit" as well to eliminate the possibility of a short in that part of the harness. So, I put in a new voltage stabilizer, ran a new wire from the fuel tank sender to the fuel gauge, ran a new wire from the temp sensor to the temp gauge, and ran a new wire from the voltage stabilizer to both the temp and fuel gauges. Got every thing back together went for a test drive with everything working great. Came home shut it off. About an hour later, went to go to the store, started the car and again, no fuel or temp gauge. This is a record; this stabilizer only lasted 5 miles. This will make the third one to blow.

I mentioned in an earlier post that my alternator was putting out somewhere around 14.6 and 15 volts to a brand new battery but that didn't seem to concern anyone, should I be looking there? When I relayed that information to Morris he seemed to think the stabilizer could handle that much volage and more. Or, could one of the gauges be "bad" and causing the stabilizer to burn?

I am at a loss.
Matthew

Don, if you were serious, the problem is that the car keeps burning out voltage stabilizers.
M Moment

Matthew

Electrical problems have to be the worst in terms of solving and frustration.

Maybe try putting in another stabilizer but leave the fuel gauge disconnected, temp gauge connected and run it for a while (hours, days. weeks?). If the stabilizer lasts longer, then it may point to the fuel gauge circuit. If the stabilizer fails quickly, then maybe put another new one in and run it again with the temp gauge disconnected, fuel gauge connected (for hours, days, weeks). If it lasts then it may point to the temperature gauge circuit. If it fails quickly, then the problem is in another part of the circuit, or the alternator.

Only problem with above test is you will have to buy a few more stabilizers. But paying a mechanic $60 plus per hour to track down an electrical problem can add up pretty quick.

I know my ammeter shows 0 amps once the battery is charged back up regardless of RPM, so if you are getting a strong positive amp reading all the time, maybe the regulator is failed. The regulator is supposed to allow just enough amperage in the circuit to run all the electrical systems that are on and provide a small positive charge on the battery. If the regulator is not working, it can possibly be pouring in a lot of amps and the weakest link is likely the stabilizer.
Michael Petryschuk

Micheal:

Obviously, you know what you are talking about because what you just recommended is EXACTLY what Morris from West Valley Gauges in California suggested that I try.
Also, even though Morris told me that the voltage stabilizer could take up to 18V, I'm thinking he is possibly not yet familiar with the new solid state versions of that unit. The new style versions may not be so "forgiving".

As per the ammeter reading, mine goes to "D" on start up then returns pretty much to 0 after a few seconds.
This is really frustrating. I really want to like this car but after having it only two months, it has given me more aggrevation than my 1974 MG Midget has in ten years total!

Matthew
M Moment

Micheal:

Are you buying solid state stabilizers? One thing you might want to check is how much ripple there is in the output voltage from the alternator and in other parts of the circuit, the rectifier might be starting to fail. You might need to get an Auto Electrician to check your alternator unless you can get your hands on a CRO. One other thing you might want to check is for a loose connection around the voltage stabilizer, you might be disturbing it enough every time you change stabilizers to remake the connection which then fails after a driving session. Take out your current stabilizer out and the put it back again and see if it starts working again.


Colin
C J Norcott

Another thing to consider is that the solid state stabilizers may have used a batch of bad components. Why not try the original type if available?
Brent B

Matthew

Sounds like the alternator/regulator is doing what it is supposed to.

We are assuming you are connecting the stabilizer with the right polarity. One end is the power in and the other is the power out. If it is being connected backwards it most likely will fry the unit. I think there is a "B" and an "I" on it. "B" is power in, "I" power out. "I" connects to the gauges.

I have reviewed the electrical schematic and can't think of much else that can be causing your problem. But for the record- does your car have any after market add on's that are electrical? Like a CD player, sub woofers, air conditioning, electronic ignition, anything? If you do, I would investigate them and how they are connected in as well. Is the fuel float original? Have you tried talking to the previous owner of the car as to what if anything he/she changed electrically or if they experienced the same problem and when it started?

Correct me if I am wrong, but the failure seems to occur after you have turned the car off and then gone back to start it up again? A power surge when turn off of vehicle? How or why I don't know.

This must be able to be solved. Don't give up. There is something in your car that is different or acting up.



Michael Petryschuk

Matthew

I find it difficult to accept that you have fried 3 VSs. The purpose of this device is to stabilize the voltage to the 2 indicators. That is to say give a constant level of voltage to these items.

I am thinking that you have a "spike" of voltage (maybe at start up) comming from the alternator's regulator. This part of the Alternator controls voltage levels and since we (the older cars) have AMP meters you will not see this spike. It could even be faster (a shorter time period spike) than a volt meter would see. There is ofcourse an osciliscope that would see and capture this event but then this is not exactly the piece of equipment that most guys have in their garage. This spike could very well be your culprite that destroys the VSs.

The voltage regulator is definitely avvailable for our alternators as I just replaced mine this spring. Not expensive and replaced in about 2 minutes.


Rick
Rick Crawford

If your "frying" solid state VR's I'd switch to the old style and replace the voltage regulator also.
JT White

I just ordered a new voltage stabilizer AND voltage regulator; should have them in a few days. I wish I had noticed that the voltage regulator was available separately; I would have switched that out two stabilizers ago. Thanks for the input, I will post results when I get the new parts in.

Michael: the only add-on is a pair of fog lamps but I've never even turned them on except for once just to see if they worked. And yes, polarity on the VS is correct and the "B" and "I" terminals are hooked up correctly.

Matthew
M Moment

Matt
I think you will find the problem solved.


for sure, let us know.

Rick
Rick Crawford

This thread was discussed between 20/08/2010 and 26/09/2010

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