Rheostat

[pupinabox]

Well, I am making progress with my interior project. Carpet set has been on order for about 3 weeks and I hope it will be here anytime. Seat covers arrived waiting to be installed. After spending most of the day speaking in tongues, I got the dash fascia in most of the way. Am having some trouble lining up some holes and a little problem with the center vents[xx(]. The dash paint looks great. Pictures coming when I get it all put together.

Anyway.......Need some advice. The rheostat was not installed when I bought the car. All the dash lights work, but I would like to install the rheostat anyway. I found the wiring. There are two red wires that have been connected together with a yellow wire. When I disconnect these the dash lights go out. My guess is that since there are four posts on the back of the rheostat that the reds go on either side and the yellow jumpers them together. Any thoughts?

[Cobber]

<b><font face="Comic Sans MS"><font size="2"><font color="black">Unfortunately the rheostat in these things is usually more trouble than it's worth, just about everyone ends up bypassing the thing altogether!</font id="black"></font id="size2"></font id="Comic Sans MS"></b>

80'Triumph TR7, 74'Jaguar XJ12 , 73'Land Rover (Ford 351. V8), 61'International AA120 4x4,
85', 69'Ford F250.
76' Ford F100
The Volvo 760 and one of the alfa 90's have passed on RIP!

[bmcecosse]

To add to this post - if I may - my dash lights don't work at all - is there a fuse just for dash lights ? Or is this likely to be failed rheostat syndrom ?

[Cobber]

<b><font face="Comic Sans MS"><font size="2"><font color="black">Probably yes put a test light or multimeter on the rheostat, if by some miracle the rheostat is working put the damned thing in a museum! Then check the earths and bypass the rheostat, [:p] </font id="black"></font id="size2"></font id="Comic Sans MS"></b>

80'Triumph TR7, 74'Jaguar XJ12 , 73'Land Rover (Ford 351. V8), 61'International AA120 4x4,
85', 69'Ford F250.
76' Ford F100
The Volvo 760 and one of the alfa 90's have passed on RIP!

[black_1980_tr7]

The wiper doesn't always touch the rheostat resistive winding, so they
these tend to be flaky in performance. I bent the wiper down into the
resistive windings to help insure contact.

I also replaced the light bulbs in the center switch console with
side illuminating, high intensite 8Cp Green LEDs TO1 3/4 sized
(much better illumination). I used 150 Ohm dropping resistors and
a reverse protection diode in series.

[Graham Robertson]

Hi, my rheostat similarly does not work, and the dash lights are fairly dim. Does anyone know if the brightness increases by bypassing the rheostat? (I'll give it a try anyway).

[KRenken]

pupinabox,

I will check my rheostat this evening to verify, but if I remember correctly the 4 terminals on the back are paired up. 2 terminals are the (-) side and 2 terminals are the (+) side. You shouldn't need or want to jumper any of the terminals together. My rheostat is working perfectly, but I will never want my dash lights set to anything other than full bright, so I'm thinking of bypassing it altogether. I'd like to use the spot that has been home for the rheostat for another ciggy lighter/power outlet.

Kimmit

[pupinabox]

This sounds like it may be more trouble than its worth. If I bypass the switch, do you suppose the lights will then be at max brightness by default?

[bmcecosse]

Yes - they will be max brightness. You could of course fit a fixed value dropper resistor in place of the rheostat - just make sure it's rated for whatever current is drawn by the panel lights.

[saabfast]

If you bypass the rheostat (just connecting the wires) it takes out the variable resistance and the lights will be a full brilliance. Not that that is very brilliant! I have tried and it did not improve things so never use anything less than max setting. TBH, I was thinking of linking it out and using the hole for a push button starter just for a bit of added fun.

Alan
Saab 9000 Stg 1
'81 TR7 DHC

[trrobbie]

Hey All, My device did work in the limerick.[;)] I took it out anyway(with proper bypassing) and used the hole for my driving light switch.[8D] I also use a push button starter.[:D](don`t remember what was in that spot orig.) Robbie(and the limerick) in wyoming

[richards]

I think only the two red wires go on the rheostat, there are however DEFINATLY only two wires on the back of it, Mine worked ocasionaly so i ripped it out!

Get a lifestyle
Get a TR7!

www.ttr7.co.uk

[Rblackadar]

I have got two rheostats and they both work!??? Holy cow!!! Call Ripleys!!!

[striker308]

Where should the wires be on the 4 terminals behind the rheostat?

Karl
1976 TR7
1982 VW Scirocco

[FI Spyder]

This should help. Rheostat in the centre.