wiring aftermarket gauges to dim like stock gauges?
 

I was wondering if it's possible (and relatively easy at that) to wire aftermarket gauges like water temp, boost, ect, to dim and brighten via that little spin thing you can use to brighten or dim the stock gauges...?

Oh and if so, how?

just take the + wire that feeds the light bulbs on your stock guages for their power source, and splice into that.

:doh: lol. Thanks

A Possibile easier solution could be to take the wire leading from the dimmer switch. That way you dont need to take the stock gauge cluster out. I could be wrong cause I have never done this, but it seems logical to me.

ZeroBanger, you read my mind. After I had posted, I was thinkin, man, to find and get to those wires, I gotta pull the cluster out, don't I?

I haven't tried looking for it, but I'm sure you can find the wire for the dimmer itself somewhere underneath it, in that mess of wires...

The interesting part comes when I'm trying to run wires for the center speaker pod gauges all the way around to the dimmer wire hehe

It is so easy to run wires from the center speaker to the dimmer switch. The key is to remove the oval center vent so you can reach the wire and pull around the center vent and bring it down near the dimmer switch. should take 10 minutes..

the only problem is that mazda engineered the stupid center oval grill so you have to remove the main dash to take it off. I pried mine off, the screws behind it break off. It still has clips on the side and top so you have no problem with putting it back on. It actually holds very tight.

Man...I can't remember how I ran the wires for the gauges there the first time around...but I coulda sworn you can basically drop 'em through the speaker hole, and grab 'em from the driver's footwell, around the vicinity of where the back of the stereo is. You know what I'm saying? Much easier than pulling the dash IMO (and when it comes to these hands, much safer for the car LOL)

I didn't take the dash off, LOL. Im saying to properly remove that stupid oval grill you are supposed to cause there are screws behind the dash to hold it in. I wasn't aware of this and I just broke the screws off. The center oval piece still holds very tight without the screws.

Thats how it worked for me, it took 5 minutes.

later.

lol..gotcha. My bad. Thanks for the info.

Splice your gauge light wires into the light for the ashtray. Then they will dim with the rest of the lights.

All you have to do is pop the center console off and you have access to the wires.

OOh...that sounds like a real easy way. Good lookin out DamonB.

I had the autometer gauge and I did that and it did not DIM.. While I would never argue with you....I'm pretty sure the ashtray light does not dim like the dash does.

My initial reaction when he said the ashtray light was "the ashtray light dims?!" lol but I wasn't about to argue, since I wasn't sure.

So what's the final verdict? (I don't have my ashtray in, I have the JDM armrest, so I couldn't check if I wanted to).

Im 100 pct certain.

I spliced mine into the power supply for the light on the cigarette lighter...

They say NOT to hook up indiglos to any sort of dimmer, BTW... So if that's what you have, you should consider that accordingly.

Light on the cigarette lighter...hmm...would that affect the power being delivered to the cigarette lighter itself??

Oh and my gauges aren't indigos. They're the defis, backlit amber like the stock gauges. But thanks for the heads up

no, the cig lighter is the most common place to wire the gauges to dim. Just about everyone uses that.
You can do this without completely removing the cluster, but its a little tight.

My understanding is that you must hook both the + and - wires for the gauge light to the ashtray light (or another pair of wires that control a dimmed stock part). My ashtray light dims, and this has been the recommendation for years as the easiest place to make the connection, so I imagine at least most cars dim the ashtray light. ZeroBanger, perhaps you only had one wire hooked up? I'm not certain how the dimmer circuit works, but I think you must connect both wires to a dimmed circuit -- connecting just the + from the gauge to the dimmed circuit and the - wire to a ground won't work.

Also, if you have an electronic gauge, this may (is likely to) mess up the way the gauge functions. I don't think the stock dimmer circuit has a proper ground, so if your gauge has one ground that is shared by the illumination and gauge function circuits, you may be out of luck.

Perhaps you could wire up a separate little knob (potentiometer) to the + wire for the aftermarket gauges to make them dim. Or perhaps someone will generously donate a circuit that will dim with the stock gauges, but allow you to only connect one wire to the dimmer for aftermarket gauges that have a shared ground between the illumination and gauge function circuits. Or you could open the gaueg and separate the circuits yourself, so that you could hook up two wires the stock dimmer circuit and have separate connections (i.e. an independent ground) for the gauge function circuit.

-Max

ZeroBanger and FDNewbie, the ashtray dims like DamonB says.
I'm 100% sure.
It does on my R1 and on a Touring '95, so it must dim on all models.

Max is correct, you have to tap both wires.

Proof is, last weekend, I helped my friend install his lighted RX8 shift knob on his car and it does dim.
We tap into the ashtray light for power source and the knob dims with the rest of the gauges(including ashtray).
I know it sounds stupid, but make sure you have tap the + and - correctly, if not it won't work at all.
Don't ask me how I know, please.
:D

Thanks guys for the info. Good point about the electronic gauges, max

Right now my gauges "dim" in a different kind of way... Don't ask me how, but the gauges work fine, and are backlit whenever I turn on the dim or low beams. Once I turn on the high beams, the gauges turn off, both operation (because they're electronic) and illumination. Go back to low beams, and they power up again lol....I've never seen/heard of that.

I guess thats why Mine didn't dim,LOL.

Dont listen to me, I dont know crap, LOL!!

To elaborate on what Max said:
It may help to picture the dimmer as a sort of electrical version of a "fuel pressure regulator". It pinches off the return line (ground), rather than changing the send line (+). Obviously you don't want to pinch off the return line to your electronics that expect the best ground possible.

It's actually a decent analogy, if you ignore the fact that the dimmer is actually a pulse/switch type, rather than a resistive type device.

I actually came up with a "design" for a lighting pulse inverter for my Defi Link setup, but as my projects usually go, didn't follow throgh with actually building it. :p:

Design-wise, it's nothing special (one transistor, if you find the right one + supporting parts)... I just didn't want to release something that would be a fire-hazard if improperly built, and used non-Radioshack parts. I was hoping to get my gauge set in, and working before tinkering with this.

Are you seriously interested? I might actually put a writeup together, when I finish my setup.

An update: I looked at the link unit PCB. The illumination isn't a simple passthrough from the illumination wire to the gauges. I didn't trace all the details, though. I noticed the unit powers on the illumination momentarily -- by itself -- w/out turning the illumination on. So, there is circuitry involved, which may freak out when connected to a pulsing dimmer. The install instructions say to connect to "12V", and a pulsed 12V isn't exactly "12V". I'm not going to bother with my setup anyway as I never use the dimmer. :p:

Max, do your digital gauges want a "12V" on the illum. wire, or will they accept a dimmer? ...or is it a mystery? :)

What about your setup Max? Still want a circuit?