Rheostat on console...

[rothsean]

I am deep into a project to replace my evaporator, but I am fixing things along the way too.

My rheostat on the center console has never worked, or at least I never noticed what it does. It does not dim anything...


So, what does it do? Also, does it have a stop? Mine just moves around 360+ degrees in all directions, freely. I took it out and am testing resistance, nothing significant yet.

Has anyone every torn one apart to check inside? If so, do I just bend those little "o" ears up?


Thanks,

Sean

[Jonathan]

It is supposed to dim the instrument back lighting. Mine spins pretty freely as well, but I don't recall if there is a hard stop in either direction. Have not taken mine apart.

As I understand it, the LED bulb swap modification and subsequent relay change obsoletes the rheostat. Maybe someone else can chime in what this means if they have done it on their car?

What wires do you have connected to the underside of it?

Here's a photo of mine from last winter when things were apart.

21689

[DMCMW Dave]

I am deep into a project to replace my evaporator, but I am fixing things along the way too.

My rheostat on the center console has never worked, or at least I never noticed what it does. It does not dim anything...


So, what does it do? Also, does it have a stop? Mine just moves around 360+ degrees in all directions, freely. I took it out and am testing resistance, nothing significant yet.

Has anyone every torn one apart to check inside? If so, do I just bend those little "o" ears up?


Thanks,

Sean

It should dim the binnacle lights only. If it has been bypassed they are bright all the time. The rheostat should be connected per the schematic, between the red-white wire and a bunch of red-orange wires tied to the headlight switch.

There is a repair kit available to fix the internals so that it doesn't spin around like that. Yes you can open it up, the resistive disc is probably not spinning when you turn the knob.

http://store.delorean.com/p-7034-rheostat-stop.aspx

[rothsean]

It is supposed to dim the instrument back lighting. Mine spins pretty freely as well, but I don't recall if there is a hard stop in either direction. Have not taken mine apart.

As I understand it, the LED bulb swap modification and subsequent relay change obsoletes the rheostat. Maybe someone else can chime in what this means if they have done it on their car?

What wires do you have connected to the underside of it?

Here's a photo of mine from last winter when things were apart.

21689

Yeah, mine is set up the same way.

[DrJeff]

It is supposed to dim the instrument back lighting. Mine spins pretty freely as well, but I don't recall if there is a hard stop in either direction. Have not taken mine apart.

As I understand it, the LED bulb swap modification and subsequent relay change obsoletes the rheostat. Maybe someone else can chime in what this means if they have done it on their car?

What wires do you have connected to the underside of it?

Here's a photo of mine from last winter when things were apart.

21689

If you go with LED illumination the only way to dim is by using a PWM dimmer unit. It switches the LEDs on/off very quickly to simulate lower level lighting. However when I did mine the PWM requires connections to the +12v and Ground sides of the circuit. Since the ground is shared between the illumination bulbs and other instruments, I needed to wire in a dedicated ground return wire from the illumination to the PWM.

I wrote this up somewhere here? It was a bit if a pain but I really wanted 100%LED dash.

[Patrick C]

I have LEDs and Cliff Schmucker gave me a new rheostat that does dim the binnacle LEDs. It used the stock wires and took maybe 5 minutes to install. I'll have to take some pictures next time I take out my shifter plate and try to figure out what he used.

[DrJeff]

I have LEDs and Cliff Schmucker gave me a new rheostat that does dim the binnacle LEDs. It used the stock wires and took maybe 5 minutes to install. I'll have to take some pictures next time I take out my shifter plate and try to figure out what he used.

Any chance you got a photo of it. It can't be a rheostat, it must be a PWM or something similar. Dave (bitsyncmaster) may know, but I think there is a less common PWM circuit that drives through the 12v side rather than the ground side. IIRC driving through the ground side is considered the prefered method by 9 out of 10 cats.

[Patrick C]

Any chance you got a photo of it. It can't be a rheostat, it must be a PWM or something similar. Dave (bitsyncmaster) may know, but I think there is a less common PWM circuit that drives through the 12v side rather than the ground side. IIRC driving through the ground side is considered the prefered method by 9 out of 10 cats.

I'll take a picture. The stock rheostat knob even fits on it. You can't tell there is something other than stock underneath it.

[WelmoedJ]

Lucas offers a replacement Rheostat that works and fits like the Original.
It also works with bulbs and LED alike.

Mine came from AES in the UK (website autoelectricsupplies.co.uk).
Stock code is 083001 price GBP 41,43 excl shipment.

[SpudMurphy]

I'll take a picture. The stock rheostat knob even fits on it. You can't tell there is something other than stock underneath it.

Did you get the photo Patrick?

[Bitsyncmaster]

Any chance you got a photo of it. It can't be a rheostat, it must be a PWM or something similar. Dave (bitsyncmaster) may know, but I think there is a less common PWM circuit that drives through the 12v side rather than the ground side. IIRC driving through the ground side is considered the prefered method by 9 out of 10 cats.

FYI:
Driving the ground side requires less electronics because you forward bias the transistor or N-channel MOSFET. To forwared bias driving the 12 volt side requires a voltage above the 12 volts. Transistors 1 volt above, MOSFET 5 to 10 volts above. When driving the ground you only need 1 volt with transistors and 5 to 10 volts with MOSFETs. So my relays need a 24 volt internal supply.