Let's discuss rheostat repair again.

[2wrench]

Couldn't find the thread re rheostat.

My rheostat works on dim only. Somebody commented that
an answer to this could be to put a jumper wire from
one electrical connection to another. This, in effect,
would be bypassing the function of the rheostat dial and
putting the lights full on at all times.

Now the particulars: My rheostat has four paddle
connections. For discussion, I'll number them 1 through
4. My red and white striped wires that connect are going
to paddles 1; 3; and 4. Paddle 2 has no connection.
Anbody know if a wire is missing that should be there
ill affecting the op of the rheo or if this aspect is cool?

Next, can somebody explain with greater specificity where
to place wires as jumpers to place the thing full on?

I think what I need to do is to place wire end connectors
onto the ends of a small piece of wire and connect two
electrical paddles (presumably at either end of the rheo)
together.

Could buy another rheo, but if other issues are at play,
a waste of time and money.

Thoughts, gentlemen -- or ladies as the case may be.

2wrench

 

[guzzul]

The rheostats have 4 connectors, but I think you'll find that each side is a 'u-shape' connector that is common, so really you only have 2 sides to the rheostat.

Just pull the wires off the back of the rheostat and jumper them together to bypass it and have 'full on'.

 

[tomshobby]

 

[DNK]

Get rid of it and put in a Smiths clock or a starter button or switch.

 

[Paul Johnson]

Get rid of it and put in a Smiths clock or a starter button or switch.

Or take it out, clean the wires and contacts and then have a fully functional rheostat once more.

 

[DNK]

Still would trust it. Too many have turned to car-b- que

 

[Keoke]

It appears 2 Wrench, your rheostat is wired incorrectly based on Tom's picture if the connector contacts are numbered consecutively ; 1,2,3,4 from left to right.--Keoke

 

[2wrench]

You know, I think I'm okay. He seems to be holding his
unit turned, like, 360 or something. I'd say it's just
what I've got. Mine's a lot more dusty, though.

Very observant of you, though. Thanks for willingness
to help.

Best of everything to ya,

2wrench

 

[2wrench]

Your feelings are rather strong about this issue. I can
tell you're a strong fan of rheostats.

I just want to goof a bit and have to be careful here.
Anbody that says to put in a clock has got to love
this part of the car.

Thinking about taking the time to clean it up and see
what happens. I'm still a baby new TR6 owner and want
everything to work as it should.

If it fries, I'll remember you told me so.

Thanks for the time to respond.
2wrench

 

[2wrench]

Do have one what looks like a ground wire that
seemed not to be connected. Think I'll screw that baby
down and see if it will affect the op of the rheo
to the good... but then, that would be too easy.

2

 

[tomshobby]

When I posted the picture I was really busy and so did not include any text.

I took the picture when I took my rheostat out so I could be sure and get the wires back in order. Mine works fine after reinstalling it.

Some on the forum are quite opinioned that the rheostat is a danger or that it does not give sufficient brightness to the dash lights. These are all good people and some have become friends, but that is their opinion and great for their cars but not for mine. And I suspect there are others that seem to favor the rheostat as I do. And that is our opinion and great for our cars.

When I drive at night I actually have my rheostat set at about mid position. I prefer not to have "bright" dash lights which I find distracting. All I want from my dash lights is to be able to glance at the gages and see where the needle points. I do not need to be able to read the numbers. And I do not need to illuminate my shirt buttons. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

 

[guzzul]

There is no 'ground' wire on a rheostat. It has no circuit of its own.

All a rheostat is, in fact, is a variable resistor. It is inserted in the lamp circuit to provide a voltage-drop to the lamps, making them dimmer.

As Tom notes, some folks are pro and some are con about this part. (And then some us, like me, are completely ambivalent.) The rheostat is not totally useless, and if you want originality then replace it or fix it. Alternatively you can bypass it and just keep the switch mounted in the dash. Mine is bypassed, but I have theft the switch and dash knob mounted - so if I ever feel the need to twiddle something, its right there.

The instrument lights, as you will know, were never all that effective in these cars to begin with. And over the years they tend to get dimmer still - partly the bulbs I suppose, and partly some internal resistance buildup in the wiring harness itself. So after 30 years, the standard lamps don't put out a whole lot of light at the best of times.

You can try to repair the rheostat. It comes apart. Just be careful how you disassemble it, make sure to keep all the fiddly bits. Unfortunately, the main component of this is a printed circuit board. And what tends to happen is the circuit material on this board delaminates, wears out or just burns. Its difficult to repair, but not impossible with some brush-on circuit board repair material.

Replacements are pricey (about $77 at TRF these days). If you want to look at alternatives, you could try going to your local electronic components shop and finding one. You are looking for around a 10-ohm variable resister that will handle the wattage in your instrument lamp circuit. Maybe somewhere on the web someone has already found something that will work.

MG used to use a wire-wound rheostat (pre-68 I believe), which might offer another option. The wire-wound ones I've seen are even more expensive than the printed-circuits, but I think they would last longer. Of course, these would not be competely original either.