early 1991 HDJ81 does not have RHEOSTAT anyone retrofit one from late model 80 or LX450? (1 Viewer)

[veiloctane]

not having a dashlight dimmer is really getting to me I was wondering if anyone has done a retrofit?

I have looked for an existing connector but none has been found to my knowledge was wondering if anyone has done this mod?

seems like I just have to find the wire that gives power to the dash lights anyone have pointers and or location wire color?

 

[mudgudgeon]

I'm pretty sure my '90 hdj81 had dimming, but it's too long ago to remember.

EWD pages for 91 HDJ80

 

[veiloctane]

I'm pretty sure my '90 hdj81 had dimming, but it's too long ago to remember.

EWD pages for 91 HDJ80

View attachment 3399085View attachment 3399086

Thanks for the diagrams looks like the dimmer is for DRL
usually DRL is both highbeam and low beam at 50℅ output.

I'm looking for dimmer for interior cluster and interior dash lights. This also includes the combo meter by the sunroof and all the dash light switches.

 

[mudgudgeon]

Hmm. You might be right. Also feeds to the clock circuit. I took that as being dash lights, but not sure.

 

[mudgudgeon]

There's chassis repair manuals in resources that will have EWDs in them

 

[veiloctane]

I've been staring at EWD for a while before I dismantle my dashboard

I have found this under illumination... I need some clarification as to which wires to tap into if the harness plug does not exist the diagram is not 100% clear to me there are 3 wires for the Rheostat switch/dial/knob

pin 1 goes to Green
pin 2 goes to White Black (ground)
pin 3 goes to Green or White Green

 

[landcrshr]

Here's what you need to know about the dimmer and why you can't just tap into existing wires without causing a short circuit.

The rheostat works by varying the voltage on the NEGATIVE side of the bulbs. The bulb "minus" is only at ground potential when the dimmer is turned all the way UP. Turning down the dimmer INCREASES the voltage on the bulb minuses, but your bulb minuses are all hard-wired to ground. Do you see the problem?

The only way to pull this off would be to un-wire all the bulb minus leads from ground, then tie all those leads together and connect them to the rheostat's white-green wire.

HTH

 

[veiloctane]

Here's what you need to know about the dimmer and why you can't just tap into existing wires without causing a short circuit.

The rheostat works by varying the voltage on the NEGATIVE side of the bulbs. The bulb "minus" is only at ground potential when the dimmer is turned all the way UP. Turning down the dimmer INCREASES the voltage on the bulb minuses, but your bulb minuses are all hard-wired to ground. Do you see the problem?

The only way to pull this off would be to un-wire all the bulb minus leads from ground, then tie all those leads together and connect them to the rheostat's white-green wire.

HTH

Yes thanks my mistake. I have to cut the ground and wire the rheostat

Looking at diagram. It’s the white black will ground thru the rheostat on pin 2

I just need to find the ground for all the dash lights and combo meter.

 

[veiloctane]

I think i might of found the wire i need to remove from ground wire is behind the instrumental pannel

looks like i remove C10 from existing ground and wire in the Rheostat

if im correct remove C10 from existing ground and wire it to pin 2 on Rheostat
pin 3 on Rheostat to ground
pin 1 on Rheostat to white green or green +12v to bulbs

 

[landcrshr]

That should do it.
You want pin 1 to go to the TAIL fuse circuit (green).