Click here for a free trip to Rio [Rheo, geit it?]

[2wrench]

Okay, gentlemen, one more time on rheostat and dash stuff,
cause I'm there and kinda stuck.

First off, there is no trip to Rio, just wanted to get
your attention. I want to discuss Rheo, you know,
rheostats and dash stuff. Dang, this is a car forum,
not a game show!

Anyway, started hooking up dash stuff. Plugged in the
headlight switch; turned them on to see where I'm at.
My rheostat is suspect, becasue when I was driving the car way back when, lights dimmed brighter; then lighter, etc, untill next to no light at all. A red and black wire coming from the dash area that lights up the little plinth panel, when moved, changed the lighting somewhat, when moved
in conjunction with the rheostat knob.

I think the rheo has been going; going and now's gone.

Three wires red/white stripes connect the back of the
rheo. Made a jumper from those three to one and connected it to one end -- and then the other -- testing if I could
bypass the unit. Got no different result in either case.

Dash is loose and hanging in the "service position." Not all bulbs have been put in place. One or two bulbs might have previously been burned out or missing. Are things not
working because everything is not plugged in? Because bulbs
are burned? Because grounds are not happening?

Grasshopper is seeking advice from the teachers. What
do you suggest? Help me Obe Wan Kanobe, you're my only
hope.

 

[DrEntropy]

First order of business is to be ~SURE~ you have a completed circuit (i.e. the grounds are in place). Have you got a 12V test light at least? That would be a good diagnostic device in a pinch with this.

 

[2wrench]

Yes, sir, I do have a test light, somewhere. Where do
you suggest I start? My headlights work. Better than
nothing, huh?

 

[DNK]

That would be interesting, BUT, the rheo doesn't control the headlamps. That is a B/W or B/R wire. The R/W wire controls the dash lamps only.

 

[2wrench]

Guess I'll go to the Master's book. Check back later.

Pulling out the enlarged schematic, cause my eyes ain't
so good. Be following the red lines, etc. Still
wondering if bulbs are unplugged, does it stop stuff
down line and like that?

 

[Tinster]

2fer-

The rheo is an ugly wothless thing anyway.
Trash it and install a nice rocker switch
that is on/off. It will fit exactly into
the rheo hole.

The gauges are so dim anywhay, who would
want to dimmer them any more?

d

 

[guzzul]

Unplugged bulbs do not make any difference.

I do not have a TR wiring diagram in front of me, but typically the only commonality between the headlamp circuit and the dash lights is the headlamp switch itself. In the middle position, it will switch on the dash lights as well as the side marker lamps (usually). In the next 'on' position, of course, it will switch on the headlamps as well as side and dash lamps. So if you have headlamp problems AND dash and sidelamp problems, it could easily be the headlamp switch. (Note: the actual headlamp circuit is not red or red/white.)

If you have side-lamp problems as well as dash-lamp problems but NOT headlamp problems, it could still be the headlamp switch.

Another common point of failure between side markers and dash lights could be the fuse. The red-wire circuits (solid red and red/white) usually come off one side of a fuse (in the Spit it is the middle fuse). Sometimes the fuse connection can be bad and will cause problems in all the light circuits downline, and this could give you problems in both the side-marker lamps as well as dash lamps, but not the headlamps. So if your headlamps work fine, but your sidelamps and dash lamps are wonky, and the headlamp switch is ok, then try checking and cleaning the fuse connections.

If your side-marker lamps and headlamps are working fine, and its only the dash lamps that are a problem, then it is probably not the fuse connection or the headlamp switch, but the rheostat.

If you have jumpered around the rheostat and you still have problems, then I would carefully check the dash-lamp (red/white) wiring itself, the dash-lamp ground wiring (black wires) and the dash lamp-sockets themselves.

 

[2wrench]

Thanks, Ross

Wiring can be fun, can't it?

Okay. Bypassed the rheo. Speedometer, a couple speedo
lights work -- red and white wires. The couple that do not work seem to be funny colors: Brown with yellow stripe; black with white stripe (or maybe purple, can't tell which).

Got a schematic for my car, a '74 TR6. I do not see anything about these funny colored wires. I think these
buggers came out of the speedo top side two out of the four
light holes there.

Then a purple wire, with another white and purple wire as well, which I beleive to be a courtesy light just under the dash on the right side of the driver blew a fuse when I put a light in -- shot from the hip and put one in that looked right -- shows how novice I can be, I guess. So, either the
way wrong bulb there or a nasty short between there and
the fuse box, I suppose.

I wonder if my car was actually wired for, like, a '75
car year or something to explain the funny colored wires? I'll check the Dan Masters reference and see.

Thanks for your consideration.

 

[DNK]

Those bulbs are not dim able. They are idiot lights.

 

[Tinster]

Re: Click here for a free trip to Rio [Rheo, geit

2wrench- Here's a close up of the correct color coded
wires that come out of the steering column.

I removed every single wire in my TR6 and replaced them
with correct Dan Masters wires. I also had great problems
getting all my lights to function. Poor grounding at the
light sockets was the problem.

I installed a new ground wire onto every light bulb in
the dash, front and rear end. Every light bulb in my car
now has it's own ground wire going to bare metal of body or
frame. Overkill? Every light bulb in my car now functions.

Hope this helps.

d

 

[guzzul]

The couple that do not work seem to be funny colors: Brown with yellow stripe; black with white stripe (or maybe purple, can't tell which).

These are not 'dash lamps' as such. The brown/yellow wiring is probably coming from the alternator to your Ignition Warning light, mounted in the speedo. As noted in another post, this is an 'idiot light'. It is not dimmable and it does not go through the rheostat circuit, nor the same fuse as the fascia lamps.

Could the other wire at the speedo be blue with a white tracer? If so, it is probably your high-beam warning light.

Then a purple wire, with another white and purple wire as well, which I beleive to be a courtesy light just under the dash on the right side of the driver blew a fuse when I put a light in -- So, either the way wrong bulb there or a nasty short between there and the fuse box, I suppose.

That is indeed a footwell courtesy lamp. The solid purple wire comes from the fuse. The purple/white wire comes off the lamp socket and connects to one side of the door-switch. The door switch provides a ground for the circuit.

The purple circuit is different from the red circuit, and comes off a different fuse from the fascia lamps (the bottom fuse in a Spit, not sure about TR). The purple wire circuit will support the horn, courtesy lights (such as the footwell lamps and boot lamp), the ignition-key lamp, the cigar lighter, and seatbelt warning light.

Back to your original post, these are not circuits that are affected by the rheostat. It sounds like the red-wire circuit is working ok if the illumination lights in the speedo and tach work.

 

[2wrench]

Gentlemen: I am exhausted; but have acheived, once again,
sweet success.

You blokes have been great! Yeah, finally saw brown/yellow
as ignition bulb going to the speedo; verified courtesy
lights as suspected, etc, etc.

Everything works! A couple bad grounds; one missing wire;
one missing ground altogether, yadda, yadda, yadda.

Bypassed altogether the rheostat. Are we going to rheo???
No! We're not!

But it sure was fun a-thinking about it.

With great appreciation,

Sincerely,

 

[guzzul]

....once again, sweet success......

Aaahhhhhh......

Well done.