My fd now has 37k miles!thanks for the writeup dale! Now I cant wait to get my car running right for dgrr

 

Dale, I recently pulled out my speedometer to fix the failed odometer problem. While I have it out I looked at the back just for a comparison. Mine is a '93 automatic transmission US spec for reference. It has the resistors in the R16 and R15 location. It also has diodes in both the ZD1 and ZD2 location.

I don't know for certain, but is it possible that the resistors on the back are an auto/ manual difference and the missing diode is the Kph/mph switch? When you got your replacement was it off of an auto or a manual?

 

With Dale's permission, I make this post. I removed the 2002 cluster from my car that I installed a few years ago so that I could recalibrate the speedo to MPH https://www.rx7club.com/3rd-generati...ter-1011051/as as well as to convert the mileage from km to miles. I also wanted to have the odometer mileage corrected so that it would show my car's actual mileage. I contacted DNASpeedometers Speedometer Repair and Odometer Repairs at Low Prices! Instrument Cluster Repair! and spoke to Drew regarding mileage correction service. After some discussion, I explained that I was going to follow both this write up and Dale's write up to recalibrate the speedo from KPH to MPH. Drew got very excited that these items had been figured out and asked if he could perform both these services plus the odometer correction on my cluster. I sent him my cluster and these two posts. Friday I received the cluster and yesterday I reinstalled it in my car, went for an 80 mile drive and checked the cluster against my GPS. I am happy to report that all is good. The speedometer matched my GPS speed when I tested at 10 MPH intervals through 80 MPH. Traffic and the presence of laser radar guns were my limiting factors for higher speed checks. It is really nice that my car now reads actual mileage (having kept records of the mileage for both my stock cluster and my 2002 cluster.) As for cost, I received favorable pricing because mine was the "test cluster" and was used to get them up to speed on these services. Therefore, you will need to contact Drew for pricing. I found DNASpeedometers was very responsive, kept me informed, nicely packed and shipped the cluster and overall performed a fantastic job. Of course, none of this could have happened without Dale's genius. Thank you Dale.

 

Ok this is kind of on topic. I need to knoe how the electronic speed sensor on these cars work. I'm wanting to hook up a live axle but am not sure how to go about doing it?

 

Hey dale? questions the jdm cluster has the overheat exhaust light instead of cel light....will the jdm cluster still use that light spot as the CEL light?

 

I haven't experimented much with the CEL light, as all cars I've worked on around here have PowerFC's. In theory, it should work, it would be super easy to test and most likely not hard to make work if it doesn't.

The little covers that go over the bulbs and show the warning lights are easily swapped, BTW.

Dale

 

Looking to do this conversion over the weekend. For those that have done it, what wattage 12v Zener diodes did you use?

I've seen them available from 1W, 1/2W all the way down to 500mW

 

I'll follow this, appreciate the write up!

 

Just wanted to follow up on this section of the post.

Yesterday I desoldered two of these 8-pin chips and swapped them on to different clusters. It works perfectly.

I was initially worried that I was going to fry the chips because the time it took to desolder them was a bit lengthy as I was going slow to try to keep the board clean and be as gentle as possible. But after soldering them back on, both clusters fired right up and showed the correct mileage stored on each chip.

Thanks, Dale!

 

we just bought a JDM manual gauge set from cx-rex here on the boards and we will be doing this very thing on it when we swap it out. Thanks Dale for such a comprehensive write up. Also I feel like you should remove the reason and details of the eeprom, for obvious reasons.

 

Pretty much completely off-topic, but I wanted to share what I believe to be the best solution I've seen for having both MPH and KPH on the same speedometer. It was the 1997 Pontiac Bonneville SSE - the speedometer had one set of numbers that went up to 220. Then there was a button on the dash that simply read "E/M" - press it and it would toggle a backlit "MPH" or "km/h" on the speedometer and the needle would swing to the correct reading for the units selected. It also changed the odometer at the same time. Simple. Clean. Effective.

Don't know why I've never seen this idea ever used again.

 

carried out the mod on my JDM speedo, which now shows miles on the digital display which is great Thanks dale
Should this mod change the needle scaling too or do I need to buy a conversion unit to divide the pulses?

 

The needle has to be re-calibrated by adjusting the adjustment screw pot and checking against a GPS speed. I think that's in the writeup how to do that, or the link to how to do it.

Dale

 

Thats great thanks, I was under the impression the adjuster moved the zero position, however must scale the reaction of the needle rather than position.

Now adjusted and the clocks are now fully converted from KPH to MPH and working perfectly, thanks for the write up

 

I'm in the middle of doing this cluster/chip swap now and noticed something different on my JDM cluster that wasn't mentioned in this thread... There is a 5 pin 10k resistor array in the RA1 spot on the JDM cluster speedometer board (there was nothing in my stock 94 cluster). Also, the 8 pin chip has slightly different markings on top.. Should I remove the resistor array so it is like my OEM cluster??

The JDM cluster was also missing the diode and I need to move one of the surface mount resistors like in your tutorial.

Thanks,

-Daniel

 

Hard to say, I'm really not an electronics genius, just got lucky . The different markings on the odo chip probably just means it's from a different batch or an updated part. Remember, Mazda made this clusters for around 10 years, so there's going to be some variation over time as suppliers changed things around.

Dale

 

Just as a follow-up, I left the resistor array on the board and have since installed the cluster back in the car... it seems to be working just fine! My mileage was transferred over and it is reading MPH. I was then able to calibrate the needle to MPH as well (took a few tries but I was able to get it to be pretty accurate to the GPS speedo app on my phone up to 80 at least). The only thing I wasn't sure on was the behavior of the boost gauge (wasn't too well versed in what it should be reading, etc), but I believe it is working properly as well (I fed the wire through the same hole as the hood latch cable and put a grommet in the hole to reduce wear).

Anyways, very happy with my new cluster. Thanks again for this guide, Dale! I most likely would not have felt comfortable doing this or even getting the '02 cluster if it weren't for this resource.

 

Very nice thanks for sharing

 

Just did this mod and it worked great. Just fyi if you desolder the resistor well enough, using a simple pair of tweezers should be able to remove the resistor from the board.

 

yes can someone please say what W rating they used?

also i already have my clocks converted to MPH i just want to change the display to say MPH, do i still need to do both mods?

thanks

 

Guess Ill add to this.

So this is my first FD and just bought it In August. The Odometer didnt work. I tried just about everything on replacing some of the known parts on the circuit board with no luck. Finally gave up and bought a non usdm cluster. Thanks to this thread I was able to convert to Miles and swap out the mileage chip. Here are photos of my swap.

When the metric cluster arrived in the mail, the first thing I did was hook it up on the car to make sure it worked. All is good.


Comparison from the Metric and Standard Clusters. My original one is on the bottom.


Both Speedo's taken out.


So just to make sure it wasnt my original cluster that maybe somewhere on the very back a connection was bad or something, I installed the Metric Speedo onto my original Cluster. All is good.


The first swap I did was change out the mileage chip. The chips taken out. I wrote USA on my USDM chip.


used my desolder gun to suck up all the solder.



USDM chip installed on the Metric Speedo,



Back in the car to test it out. IT WORKS!!

 

The Second thing I swap/changed on the Metric cluster was ZD1 (i added another one of these as the USDM had it installed where as the Metric cluster did not have one installed). I simply removed it from the USDM cluster and installed it on the Metric cluster.
Picture of ZD1 removed from the USDM Cluster




Picture of the Metric Cluster when no ZD1 installed.


Installed

It doesnt matter if on this side of the circuit board the solder touches with the other solder joint as they are both on the same path. This was how it was originally before I removed it.


The Third part i swap/changed was R14/R15. This resistor (correct me if im wrong) is installed on the R15 joints for the USDM. The Metric cluster has it on the R14 joints as pictured below.



I removed it from the R14 joints and installed it on the R15 joints as pictured below. Just be careful when removing it as it appeared to have some sort of adhesive glue of such holding it down other than the solder.


After those two parts were changed, I plugged it back in to the car to test. IT WORKS!!


So the last thing I did which you dont have to unless you like driving around always looking at your speedo in Km, was swapped out the speedo gauge.. Below picture shows comparison.The Metric gauge is really clean and not cluttered up, but I wanted to keep mine original to the car.

 

I went ahead and swapped out the blue screw thing, not sure what its for but appears to be adjusted for something. So I figured id take the one off my original gauge and swap it onto my new metric gauge since I am now using the MPH USDM speedo gauge.


before removal, this is from the metric gauge


before removal, this is from the USDM gauge


Both removed.


Installed


All installed and hooked up on the car. looks good.



So as of right now, I have not test drove the car to see if the Speed gauge reads properly. Will do it later. if it does not work right, then ill have to find a way to dial in the speedo or just swap back to Metric speedo guage and swap the blue screw again.

Also would like to note that when I first hooked up the Metric cluster on my car when it arrived in the mail, I took my car for a drive cause I read that people said the Cruise Control did not work when the Odometer didnt work.Will My Cruise Control didnt work. I didnt work when I bought the car, I figured it was because my Odometer wasnt working. Well It still didnt work with the Metric Cluster. So I am thinking that there is something wrong with the Cruise Control and has nothing to do with the Odometer.

A Question I have is does the Trip A and Trip B not work or not supposed to work on these cars? Only has one Trip and pressing the button resets it? Cause when I press the button it resets the trip.
Another question I have is why do the RPM and Speedo needles not light up near the tips? is this how it is?

UPDATE!
Alright had a chance to take my car out for a spin to tune it the Potentiometer (thanks for that DaleClark). So it took me three tries and the speedo gauge is almost spot on with my gps app. Also i was able to use my Apexi Power FC controller to compare the KMH to what my speedo read. So for anyone curious which way to turn the potentiometer (the blue adjustable screw), turning it clockwise will decrease the value of the speed gauge and turning it counter clockwise will increase the speed value.

 

Nice! Glad that worked for you!

The blue screw thing (potentiometer) shouldn't need to be swapped, you just use that to fine-tune the calibration. I think in the beginning of this thread or another thread I have you can learn how to GPS-calibrate your speedo. It's not hard and only takes a free app and about 10-15 minutes of driving around to tune in.

I have a big thread on cruise control and how that system works, you may have more troubleshooting you need to do on the cruise system.

There is no Trip A and Trip B on the FD, it's just one trip display that you reset with the button.

The lighting near the tips seems normal.

Dale

 

Thanks Dale, you the man!!

I was able to drive my car last night and the speedometer doesnt read right, hehe, guess it didnt matter swapping out that blue screw. My GPS app on my phone was reading 45 MPH and the gauge was reading 70 MPH.

Yeah I saw your thread on the Cruise Control, I will have to spend some time one of these days and go over it, not looking forward to it.

Thanks for confirming the Trip display.