Defi gauge problem (dimmer)
 

Yes I searched...

I went to FD3S.net and did the transistor and resistor thing and I still have the same problem....
My Defi BF gauge will flicker if the dimmer is in anything other than full up or down; it also dims opposite of stock gauges...This is drivin me crazy!!!

Here is how I have things wired from the control unit:

red--+battery terminal
Black---Neg Battery terminal
Orange---Ign II
White---to the collector terminal of pnp transistor
Base of transitor---3K resistor to the R/G wire (used the headlight washer wires as they wern't being used)
Emmiter of transitor----R/B wire (used the headlight washer wires as they wern't being used)

Any help is appreciated.

Thanks
Marshall

^^

Aww the transistor didn't work!!!!!\

Well free bump for a guy in need. Can someone give who has messed with the Defi system give him a hand?

thanks,
-josh

I'm not familiar with DEFI. However, for most gauges, you simply attach your illumination wires to BOTH of the ashtray light wires. This allows most gauges to work properly with the factory dimmer.

Well, this doen't work! Also, my voltage is not staying consistant--jumping around. Could be a bad volatge regulator?
I need the electrical GURUs....

Ok...my damn crappy autozone lifetime warrenty alt is crap--so I have to replace it---arrrgggg!! This might solve my problem with the flickering....The voltage is jumping causing the lights to go bright then dim, bright then dim etc... So I'll replace it this weekend and see if this solves the problem....The transistor should work....Stay tuned same bat time same bat channel!

Ahhhhh...... Marshall I had concerns about that alternator when you bought it. Thank god it has a life time warranty!!! Hopefully the next one will hold out longer than a month.

goodluck,
-josh

You can say that again! Well, at least I'm my own mechanic!

alright bringing this back up! The alternator is fixed...the wiring was checked 100000000 times and I have it hooked right according to FD3s.net...I also read this thread https://www.rx7club.com/3rd-generation-specific-1993-2002-16/some-defi-standard-gauge-install-%2Afacts%2A-239260-printthread/ and I am still stumped and no one is able to solve this problem...Is it that hard...I have Defi, my Circuits teacher, and an EE at my work trying to solve this problem...ARRRRRRGGGGGGGGGG!!!!!

The dimming opposite of stock gauges means you tapped into the wrong illumination wire. Been there, done that. Use the R/G wire instead.

I wouldn't think you'd need the diode and all that jazz. My Greddy gauges light up perfectly and dim perfectly with the stock dimmer system.

Dale

Trust me when I say it is not a wire reversal problem...If I connect the illumination wire to the R/B only, the gauge goes into dim mode and still flickers under certain condition explained above(the Control Unit box of the Defi unit controls the gauge). If I connect to the R/G wire the Control Unit box light opposite of the stock gauges(defi gauge still has problems)...The PNP transistor flips the signal and the Control Unit lights w/the stock gauges--BUT the defi gauge still flicker under conditions! Here's the deal...the Control Unit sees the PWM signal (on, off, on, off, on...etc)...the Control Unit Box, as with the rest of the stock gauges, flicker fast enough for our eyes to not see the on-off cycle...But(and here is my theory) the Control Unit processes this as on-off, again under certain conditions, and makes the gauge flicker and a slower rate and becomes visble by our eyes(something like that). So the problem is somewhat hidden...This is where the difficulty begins! Sure I can use the gauge under the "working" conditions but that is half arss in my book. So, if everyone with electrical knowhow puts their heads together then we can solve this problem!

Not sure if you connect the wire correctly but the Defi BF gauge use its own control unit to control dim.

BC

I am aware of that...The control unit itself dims with the stock gauges...it is here where the problem is as stated above!

makes me think twice about getting defi now..

don't get me wrong here the gauge works great...just me being very anal here! The flickering is only when the lights are on and the dimmer switch and control unit are in a certain position. I love the gauge!

Electrical Guru's needed...

The dimmer is controlled from the ground side. You need to have two wires for the dimmer to work properly. On the ashtray light: R/B is the positive wire. R/G is the negative wire. These wires can also be found on the main radio (12-pin connector) harness.

Joe

Ok...I've narrowed it down to 3 solutions: 1. Get Defi to modify the control unit to work w/the car's dimmer(highly unlikely)... 2. Make some kind of circuit to convert an oscilating (on/off) signal to a 0-12 constant voltage(I like this as I like messing around with complicated things)...3. Use a POT to dim the control unit(I don't want to do it as its just one more switch to adjust)...So as #2 looks like the solution any electronic experts out there willing to help me and anyone else with a Defi gauge or similar solve this....So basically we need to figure out how to convert the oscilating signal on/off (time ON varies with PWM switch postion) to a varying 0-12V(based on PWm switch position). So lets get to thinking!!

Well I finally got the official answer from DEFI. Here it is:

Hi, Alvin.

I assume as long as you have hooked illumination led from PWM affected line, you can not escape from this issue. Now I have asked our engineers about this issue. but they said that without reconfiguring the program inside Defi-Link Control Unit II, you can not change the switching timing of illumination LEDs of Defi-Link Control Unit II. This is unrealistic solution.

I'm sorry to say but, you should change the point to hook illumination signal that is not affected by additional PWM. Of course you can not change the brightness of the Defi-Link Control Unit, but not to flicker the gauge, this will be the most practical way.

Thank you and best regards.
Hiroshi Kagami
Defi

So now off to my other choices...

Sounds like some garage fun is in need. Call me because I need to rerun my gauges also. See ya this weekend!!! hahaha

-jjosh

sorry to bring this up..so which is the best way to wire these guages up than? which wire for the ilumination?

This is for Defi gauges (it may apply to others)

From FD3s.net

Let me expand on the reason for this: Mazda chose to use pulse width modulation (PWM) to dim the dash lights.

One side of the lights is connected to +12 volts when the light switch is in any position other than "OFF". The other side of the lights are pulled to ground with pulses: the longer the pulses, the brighter the lights and vice versa.

This is very effective but annoying for many electronic gauges that have a +12 power line, an illumination line, and a shared ground for both. If this is the case for your gauges, use a PNP transistor with the emitter tied to the switched lighting +12V signal, and a 1K - 5K ohm resistor between the base and the lighting PWM (pull down) signal. Then the collector can be tied to the illumination line of the gauge. I know this works because it is what I have in my car.

Nashman69g’s addition

This will eliminate the flicker when the dimmer switch in the car is in a position other than full bright or dim. In addition to FD3s.net, use a 1K resistor and a 47μF capacitor in parallel between the collector/illumination line and ground. The brightness of the Defi gauge is controled from the control unit. See the attached diagram.

Nash,
I am about to install the D-series gauge on my FD. what part number did you use for the transistor? Did you use a 1-5K pot for the base? Do you have any pics of the board & where did you stash it? I'll PM my email addy.

on my defi's i took my switch live from the ashtray illumination light and live from the stereo, its very easy to wire up - just pop the cover off the centre console.

i also had the opposite illumination effect - try swapping the guages output to the other output on the control unit - i had to use output 2 to get it to work good

my gauges work fine. try wiring to the ashtray!

Well I think the biggest issue is that I have the BF series...I'm not sure how the other series are affected.