lost my tach after ebrake indicator fix??

[Souls]

Hey everyone,

So I've installed my own little LED in the spot on my cluster where the ebrake indicator is. ( history -> I've disabled my DRLS for HID, with the ebrake switch, which is easier than all the relays to keep stock function. )
The LED is not installed on the circuit board itself, but over top the existing, with a piece of tape over the original SMD, notched out a path for the wires (used old stripped LAN cable) on the cover that separates the indicators lamps. and ran it down to the ebrake area. ( I hope this makes sense without pics)

So I finally get around to sending power to the LED, I look up the resistor value and open the ebrake trim to get power. hook up a fuse, connect GND, and tap the power the to leads to see if the new LED will light, it didn't, so I swap resistors and try again... nothing, 3rd time and my tach moves up to 2000rpm and drops??? WTF? I know that absolutely nothing is touching anything on the circuit board (cluster) for this to occur. now my tach will only move from 0 to 500 rpm ! F'n hell.

any ideas? I wasn't even gonna put in a new LED in there, since I drive my car mostly and don't forget about the ebrake being engaged. but I wanted to get stock function back to that one thing.

SOB :flaming the only thing that comes to mind is maybe since it uses CANBUS signals (which I have no idea what signal protocol is used) when I briefly hit power , the tach picked up a signal of some kind? which I could understand since I used UTP wire, but to lose functionality completely doesn't make any sense.

[Noisy Crow]

I'm confused... where did you connect the LED +ve and ground?

If you connect the the +ve of the LED to the e-brake wire and -ve to ground, that's just like applying the brake (grounding the wire from the PJB) and the LED will light if the PJB can supply enough current. If you hook the -ve to the PJB wire and the +ve to 12ou are probably reversing the current flow into the instrument cluster, which could result in all sorts of bad things happening.

If you want to use the e-brake switch to light up the LED when the brake is on you need to add an isolating diode inline in the wire between the e-brake switch and the PJB, and then connect the -ve of your new LED to the brake switch and the +ve to a switched 12V source.

BTW, don't forget that by hiding the e-brake indicator you are have also remove the brake-failure indicator.

[sas]

The CAN bus is well protected from errors , with noisy signal you would have an error immediately.Check if your LED is really so well isolated. Wondering, there almost always are empty windows for leds, why over another led. Possible the needle was installed incorrectly, there is used a stepper motor with zero position sensor. Before assembling the control panel ,you have to connect panel without needles to reset the position of motors. After ignition was switched off put needles to point on the mark, look carefully there are special marks on the border of the scale. Put them, then enable and disable the ignition to check that needles are really were set correctly.And remember, that any connection and disconnection of control panel should be done with disconnected battery. These experiments with control panel might be very expensive.Resistor for LED should be 1 -1.8 kOhm.

[Souls]

I'm confused... where did you connect the LED +ve and ground?

LOL I see your confusion. I made a fresh connection, I snipped the ebrake wire and connected that to one of the ebrake bolts to maintain the ground (DRLs off, but indicator on), then took +ve from the ciggy lighter and re-used the ebrake switch as my new switch having it break the -ve (since it's bolted to the ebrake arm)



BTW, don't forget that by hiding the e-brake indicator you are have also remove the brake-failure indicator.

yeah I know



The CAN bus is well protected from errors , with noisy signal you would have an error immediately.Check if your LED is really so well isolated. Wondering, there almost always are empty windows for leds, why over another led. Possible the needle was installed incorrectly, there is used a stepper motor with zero position sensor. Before assembling the control panel ,you have to connect panel without needles to reset the position of motors. After ignition was switched off put needles to point on the mark, look carefully there are special marks on the border of the scale. Put them, then enable and disable the ignition to check that needles are really were set correctly.And remember, that any connection and disconnection of control panel should be done with disconnected battery. These experiments with
control panel might be very expensive.Resistor for LED should be 1 -1.8 kOhm.

response from bolded ubove
- good to know

- I wanted to use the same indicator symbol

- entire cluster was fine after I installed the LED, and it (LED) sat for 2weeks unpowered), I did follow the procedure from "Commie's" post in Mz3.com about cluster lights

- when I connect the cluster all needles move and reset themselves, even now, the tach tries, but no go. I'll prob have to pull its needle off and reset again. I hope that works. if it does, I'm leaving it alone - indicatorless

[sas]

Check, also, inside of the needle cap have to be a counterweight.

[Souls]

Check, also, inside of the needle cap have to be a counterweight.

LOL, I can assure you that your reply, though well intended, has nothing to do with my electrical issue :chuckle

[sas]

Most like something was fried there. Look ,e-brake led is near from tachometer motor.
I think the positive wire touches one of those pins.
http://i709.photobucket.com/albums/ww96/sas2000_album/controlpanelbrakeled-1.jpg

[Souls]

wow, great shot... I'm just about to pop it open now actually!

Thanks for that, 'cause there are lots of solder points that I wouldn'ta known what they were for. after seeing your pic, I'm am suspecting that there was contact - at the 1o'clock point next to brake LED in your pic , which makes me PO'd 'casue I was very careful about that.

will post in a bit, my findings

[Souls]

well SOB :flaming :bang that one tiny little point may have been in contact with the lead of the LED. the tach is reset to zero, but still doesn't give a reading, only moves slightly. What I don't understand is why the needles all twitch after being pulled and put back in - odd, definitely built different from my old VR6 cluster.


grr.. I've disconnected the battery, I hoping that there's a far shot that everything will reset once reconnected.

fingers crossed :(

[sas]

Eeh, I’m afraid that applying 12v to 5V circuit is fatal and couldn’t be restored.These are multilayered boards, and the tracing where the circuit from this pin comes is almost impossible. I have no idea about exact construction of this motor .Logically , these 3 separated pins are outputs from position sensor. For longevity of such motors often are used a hall sensors which are sensitive to an over voltage. There is a chance that the motor replacement can fix it.There are only few control points where motor knows the exact position from sensor, remaining positions are pre-calculated by controller from done steps. Needles are jumping when they have a different position from what the motor controller was preprogrammed. It’s motor seeking a right position.

[Souls]

off to the Classifieds for me.... :tomato

[07m3gt]

so are you gonna buy a new cluster or try in find a tachometer motor ?

[TheMAN]

something tells me he wished he has gone the "hard way" of disabling the DRLs now instead of mucking around with the gauge cluster
a brand new one is nearly $1000, and requires installation by the dealer (needs to be married to the car, and it also holds the immobiliser system I think)

I hope he has better luck from now on

[07m3gt]

something tells me he wished he has gone the "hard way" of disabling the DRLs now instead of mucking around with the gauge cluster
a brand new one is nearly $1000, and requires installation by the dealer (needs to be married to the car, and it also holds the immobiliser system I think)

yup Correct to all of the above. Messed mine up too changing out the leds cost me like 380 to fix i bought a used one too. Now i`m stuck with the old cluster millage that sucks lol

[McGuyver_3]

been there done that on my 05. had to have the dealer reprogram the car to the cluster did it 2 times 1 time for the gt cluster instal and then again for the back to gx cluster. long story as to why. But I found a cluster that was super close to the mileage that the car was supposed to have on it
check ebay you will find cheap clusters there

[Souls]

something tells me he wished he has gone the "hard way" of disabling the DRLs now instead of mucking around with the gauge cluster
a brand new one is nearly $1000, and requires installation by the dealer (needs to be married to the car, and it also holds the immobiliser system I think)

I hope he has better luck from now on

meh, I still am happy with the way I did it. I was only restoring the indicator for the the wife really. live and learn

GX and GT clusters are different? (I still not as thoroughly knowledged about Mazda intricacies, like I am(was) for VDubs)

[Souls]

so are you gonna buy a new cluster or try in find a tachometer motor ?

so I obtained a donor cluster from SFW, popped and swapped the tach motor, same issue. boooo. I'm still very satisified with the "easy" way I disabled the DRLs. I wonder why Engineering changed the circuit for the 07's, to include a fuse. I guess it's gotta do with running the high beams as DRLs.

until my wife notices, it's OK... I'd like to grab fresh meat from a scrap yard, but as I mentioned to SFW, 3s don't seem to end up there easily!