TR6 Local source for TR6 3-prong oil switch ?

[Brosky]

Anyone ever use a local for the three prong unit and do you remember the part number?

Thanks,

 

[mrv8q]

Paul, GUZZUL wrote this on March 14:

Also, to answer another post about the TRF part number for a 3-prong switch, there are some variations, so you need to check your commission number. The one for my Spit is GPS113.

This switch is plug-compatible with a standard GM switch, as used on 1979 GM models with a 5L engine. Olds Starfire, for example. Standard's number is PS-64. NAPA number is OP6610 (Echlin unit). $10.50 versus TRF's $24.95 and readily available at pretty well all engine parts places.

If you do a Napa search for "oil pressure switch" you will also bring up the links to their OP Switch sockets. Again, these are generally available from parts stores, in the range of $6-10. Makes it easier to get 'em off.

 

[Brosky]

Kevin, thank you very much.

I'm a little bit tappy tonight, well maybe a bit more so than usual, in case you read my answer to building Triumphs again.

In any case, I should have remembered Tom's post about the cover. I did put my 2 cents in, but quickly forgot.

I will write that down and pick one up tomorrow, since I'll have nothing better to do with the cold weather and snow on the roads.

 

[mrv8q]

I will write that down and pick one up tomorrow, since I'll have nothing better to do with the cold weather and snow on the roads.

Paul, I'll do the same, except it'll be 65 degrees here tomorrow. Hopefully, I'll be taking my 7 year-old daughter to a local British car show Sunday. She's looking forward to the hot chocolate from Starbucks...

 

[Brosky]

I'll be drinking hot chocolate too, but because I'll be freezing my butt off!!!

 

[DNK]

Paul, I can't remember how stock your car is,or is it a rest-mod like Bills. I would think, if memory serves me right,that the other wires go to some kind of run on valve, hasn't that been a problem with batteries running down? is it possible to eliminate that wire and run a single wire style as in earlier models. I guess Dan is the guy to answer that.
Don

 

[tr6_easyrider]

Kevin, WHere is the British car show?
joe

 

[Guest]

Paul, I can't remember how stock your car is,or is it a rest-mod like Bills.

It WAS stock but now he seems to be coming over to the Dark Side. HeHeHe
<span style='font-size: 8pt'>~whispers in his ear~ Paul, aluminum flywheel. Aluminum, Paul. </span>

 

[tomshobby]

Bill and Paul,

All I got to say is you guys are a bad influence. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

Paul, when you get the correct oil send unit for your car could you post the part number?

Thanks

 

[Brosky]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]It WAS stock but now he seems to be coming over to the Dark Side. HeHeHe
~whispers in his ear~ Paul, aluminum flywheel. Aluminum, Paul. [/QUOTE]

I'm getting there. Pictures, Bill, pictures.

First step, triple carbs this summer and drive car like never before. We only have 54,000 miles over the past 33 years.

Second step. Find spare 74 motor that will get work done to it over the next winter and be ready for spring drop in.

My triple switch failed and that's why the anti-run on drained the battery. I need to replace it and reconnect the anti-run on, because without it the oil and engine lights don't work.

Luckily, this switch / valve conflict was explained to me in these two threads:

https://www.britishcarforum.com/bcforum/u...true#Post228124

https://www.britishcarforum.com/bcforum/u.../gonew/1#UNREAD

 

[DNK]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]

My triple switch failed and that's why the anti-run on drained the battery. I need to replace it and reconnect the anti-run on, because without it the oil and engine lights don't work.

I not to sure of this. If you run an earlier switch the WN wire that goes to the light than feeds the brake light . Take a look at Dan's schematic. Of course I am not an electric guru. Somebody look at the drawing an see if I am right.

 

[Brosky]

OOPS!!! Sorry, but my mistake. I should have said brake light, not engine light.

It's all Tinster's fault. He got me all upset with that nice weather and the fishing and, and...I screwed up.

 

[mrv8q]

Hey, Joe, less a British car show than a gathering... more a Healey thing, but all Brits are invited: Sunday, 9:00, Golden Cove Shopping Center, Rancho Palos Verdes. Quite a drive for you, and probably not quite worth it, but for us locals, something different...

 

[guzzul]

That should still not be the case, if your OP switch is wired correctly. I don't have a TR schematic in front of me, so I can only go by the Spitfire, but I suspect these are the same.

The OP light and the Brake/PDWA light get their power from a terminal on the ignition switch. All the OP switch is doing is providing a ground when the oil pressure drops below about 5-8 psi. When the pressure increases the switch opens and the light goes off. The Brake light ground is provided either by the pressure-differential switch or by your handbrake switch. But it does not depend on the OP switch to operate.

The only difference between the three-prong and single-prong OP switch is that the three-prong toggles the ground between the OP light and the anti-runon switch. When OP is low and the ignition is on (in "run" mode) you have power to the OP light, and a path to ground through the OP switch. But there is no power available to the anti-run on valve.

When you turn the igition switch off, power cut from the ignition circuit and from the OP light, but is applied to the anti-runon valve. The valve has a ground available through the OP switch because there is still oil pressure while the engine is turning through its last few cycles. This circuit energizes the anti-run-on valve, which applies a little vacuum to the carb float bowl, enough to stop the engine from drawing fuel.

As the engine comes to a stop, the oil pressure drops below 5-8 psi and the switch flips to open the run-on ground and close the OP light ground. So the run-on valve should now de-energize. Voila.

So if you do have a short to ground in that white-purple wire coming off the anti run-on, when you turn the ignition switch off you have a live circuit, which would keep the valve on (and drain the battery).

You need to make sure your three-prong switch is wired correctly, as per Roman H's post. If not, you can get some funny results which could account for your brake light problems.

Also, if one wanted to move to a single prong switch, you could do that. The single prong grounds itself I believe, through the body of the switch. So you would just disconnect the anti-runon and ground wires from the current switch (I don't believe any other circuits use that OP switch ground, don't know whythey would). The single terminal would be use to connect to the OP light and provide a ground for it before the pressure built up.

Sorry to be so long winded......

 

[DNK]

I get it, duh , The power goes thru the valve and then to the oil pressure switch. I had tunnel vision instead of looking at the big picture.

 

[guzzul]

The power goes thru the valve and then to the oil pressure switch.

Yupper. When the igition switch is "off" (not in 'run'), power goes from a terminal on the ignition switch to the valve (via a Brown/Red wire in a Spit). The valve itself has no polarity. A White/Purple wire comes off the valve and goes to the OP switch, which, when oil pressure is high, toggles this connection to ground.

So you need to be ignition-off and oil-pressure-high for there to be a circuit.

Unless of course the White/Purple wire has found it's own ground somewhere else, in which case you've created a battery-drains-when-not-in-use circuit.

 

[Brosky]

Looks like I have a bit more to check. It was wired correctly, as checked by two of us, but the darn thing kept either making the A/R valve stick or the valve is bad. But I was told it wasn't and I know that I had dead batteries and a A/R that when disconnected, stopped the problem.

 

[Brosky]

Ross, I forgot to mention that it's been too cold here to work in the garage on wiring, as I'm sure you know, being in Ontario. I have not had the time to go through the process to see if I have a chaffed or grounded wire as suggested in the links that I posted.

That repair will be done as soon as it gets warm enough to work out there or in the sun in the driveway, now that I got the valve cover and a few other odds and ends done.

I want everything in tip top shape when the carbs get here, which should be in a few more weeks. As the weather goes, it doesn't really matter.

 

[RomanH]

Paul,
A quick way for you to check the A/R valve is to disconnect the lead wires from it and jumper it straight from the battery. If you hear a "click" when you make the circuit and another when you break the circuit then the valve is functional.

 

[guzzul]

It was wired correctly, as checked by two of us, but the darn thing kept either making the A/R valve stick or the valve is bad.

My last two-cents here....

As RomanH noted, you can easily check the valve operation. But you can see how there should be no circumstance where the valve can operate when the ignition key is in Run. Unless the ignition switch is faulty or wired wrong, there will be no power to the valve unless the ignition is 'off'. Even if the OP switch is wired wrong you should never get a condition where the valve has both power AND ground when the ignition is 'On'.

Also, if the valve itself is faulty and is mechanically sticking open, that by itself would not drain the battery. However, it would be pretty difficult to start the engine, since you would have a permanent vacuum bleed to the float bowl. (...ask me how I know....)

As for winter....well we just have to ignore it for a little while longer...polish the wrenches one more time...reread Triumph World... stare at the snow...hang around the forum....