After years of dreaming of the 99 Spec gauge cluster, the one with the 6'O clock tach, I finally purchased one via Jesse Lau. My FD has been in the shop for awhile but I finally got it up and running. The first thing I did when I got my car back was to install the long awaited gauge cluster. Well, I installed it last week and to my great disappointment and heartbreak; it didn't work . I emailed Jesse and he instructed me that everything should work except for the built in boost gauge (which replaced the oil gauge). The only thing that worked is the gas and temperature gauges. I have no clue why the tach or the speedo doesn't work. Could it be the incapability of US ECU vs Jspec ECU? I have the PowerFC if that makes a difference? I thank you guys in advance for any input or advice.

Sincerely,
Dino

BTW: Jesse is a straight up guy so I know he didn't sell me a bunk gauge cluster

 

Haha im glad I didn't buy that hunk of junk off you! Just kidding, glad you got your car moving Batmo! Too bad im not in Cali to race you, 350RWHP now babay!

 

How did you get 350RWHP with all them duct tape under the hood lol!! Is your FD dynoed yet? Thanks Q for blessing my FD

 

Should be fine, check the relays and fuses maybe one blew after the install.

 

Have done this conversion before, but it was a while ago.

The pin-out is different.

Straining the memory here, but the tacho wire on the S-8 dash is looking for a signal, yet the incoming pin on the S-6 harness goes to ground.

Something like that.

 

Relays and Fuses are fine because I plugged the OEM cluster back and it works fine. Darn...what can it be?

 

I'd check into DMRH's explanation. See if you can get a wiring diagram for the '99-spec dash and compare it to the '93. Good possibility that some pin locations in the plugs were changed (especially with the boost gauge conversion).

 

Yeah that is very interesting but before I do that, I will try to install the gauge cluster on my buddy's FD and if that doesn't work then i'll research the diagram.

Thanks

 

did you get the dash harness from the '99?

 

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No I just got the the cluster only but that is a good question. I wonder if that makes a difference?

 

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What is the hell is going on Series7...you be leaving you dots everywhere lol!

 

Any other suggestions?

 

no, but whos the girl in teh sig??

 

oh thats my girl , i felt sorry for Bats so i let him borrow her,

 

I have a guy down in san diego who is doing the same on his FD , i believe that you need the dash harness and the main engine harness for the gauges to work right in the dash.

 

I am certain that, apart from a pin or two, you can make it work.

The series-6 (92-95) body wiring harness is almost the same as the series-8 (99-02) dash cluster.

I will now chase up what I actually did to make it work & post it again here.

I'm almost sure it was as easy as snipping a few wires for the plugs & changing them around. Once I did that, BINGO. Speedo & tacho came up. (they work off the same signal)

Boost gauge is independant I think. I made it work off the MAP sensor signal line. You could try it, but I did install the 2-bar map sensor & 16-bit ECU from a series-8 to this series-6 using the series-6 body harness but a series-8 engine harness.

Shall get back to you all after I check it out again & refresh the memory

 

Hey thanks man! I'mma swap out my buddy's OEM cluster and put in the 99 to see if it'll work on his.

 

Alright here is the update:

We installed the 99 gauge cluster on my friend's 94 auto FD and the our surprised it worked We then took his auto gauge cluster and installed into my FD and his worked. I am lost for words now. I am thinking that perhaps it is ecu related.

 

OK, I spoke to the guy I did the S-8 instrument conversion for. He remembered we cut 2 wires on the S-6 wiring harness.

Which 2, he didn't remember, he also wasn't about to let me remove the instrument cluster to check over my old work.

So this is how it is.

The S-6 didn't have a boost gauge so there is no dedicated wire leading from the ECU to the instrument cluster inside the harness. Its not as easy as using the old oil-pressure wire as that now goes to a light.

You should also remove the electric oil-pressure sender on the rear plate & replace it for the standard pressure-switch, required to turn the light on & off.

You still need a line from the ECU to the instrument cluster now.

I think there was multiple NEG lines that come up through each of the 3 plugs. Mazda got rid of one of these & used the spare pin as the boost gauge signal wire.

Your job is to compare the plastic membrane on the back of your S-6 & S-8 instrument cluster. You will spot a pin which leads to a NEG on the S-6 but the S-8 has that same pin going to the boost gauge signal.

Cut the NEG line out & run the wire to the ECU. Tap into the MAP sensor signal & it should then work.

Doing that should also get the Speedo/Tach working too

You have to remember that despite looking very similar. Mazda made lots of wiring changes between lhd & rhd versions aswell as S-6 to S-7 to S-8.

From all the work I have done, I estimate that about 40% of the cars wiring is different from the S-6 to the S-8 versions.

REgards

If worse comes to worse..... I should be at SEVENSTOCK-6 in late SEP. If you are a SOCAL guy. I may be able to help out personally.

 

DMRH,

Hey thanks a lot bud. I will try it this weekend but I am still puzzled why it worked on my friend's 94 auto FD?

 

just wondering....how much did that entire cluster cost you??

 

Man..If I don't get this thing to work, I'm just gonna sell it.

 

As stated. I should be in L.A for Sevenstock next month. So if your really stuck. I can make it work for you.

Now I will get a little technical....

Pin 1A on your S-6 IC (instrument cluster)..... is a NEG switch from the diagnosis port that turns on your warning lights.

Pin 1A on the S-8 IC..... is the incoming NEG signal from the oil pressure switch (located on the rear plate)

Pin 2F on your S-6 IC..... is your incoming "variable" NEG for the oil pressure gauge

Pin 2F on the S-8 IC..... isn't used

Pin 3J on your S-6 IC..... goes to the low oil level light

Pin 3J on the S-8 IC..... is the boost gauge signal wire from the MAP sensor

Pin 3L on your S-6 IC..... is the NEG signal from the cruise control module that turns on the dash light

Pin 3L on the S-8 IC..... is the NEG line to chassis/earth. For the boost gauge

Ok, I originally thought we changed only 2 wires but the reason may be becuase I wired in the S-8 (16-bit) ECU to this S-6 too. Basically, I turned a S-6 into an S-8 with everything changed except the wiring harness, customer would have saved if he had just bought the harnesses & I could have plugged everything in.....lol

If you do all the above (swapping wires around) & it still doesn't work, then its a compatability problem for the S-6 ECU not being able to drive the S-8 speedo & tacho. As previously stated, they may look the same but Mazda made a lot of electrical changes between the S-6 to S-7 to S-8