help with digital gauge...

[poneyrunner]

ok.. so i have a 1989 240 sx 5 speed car that came originally as a sohc but i converted to a dohc.. everything in the car works perfectly.. i currently have an analog gauge in which works perfectly no problems what so ever with it. well recently i bought a bunch of parts from a guy parting out his 240 with a ca18 motor and one of the pieces was a digital gauge cluster which worked in his car (i tested it and it turned on perfectly). i brought it back tried to install it into my car with my harness and everything worked except for the speedo.. speedo did nothing. so i thought it was my harness so i got one of my buddys to bring me his harness and tried his and same thing everything worked except the speedo. so we tried it in his 89 sohc 240 with both harnesses and they both worked perfectly.. so that is 2 cars in which this gauge cluster worked perfectly but will not work in mine? what could cause that? it tried wiggling my wires a bit while the key on, pushing and holding the mhp/kph knob in, turning the mph/kph knob and anyother knob i cold find with no luck. im lost and none of my friends have any ide about it... thanks for the help.

[asoomal]

There's two kinds of clusters, one for DOHC and one for SOHC.

Try a DOHC one.

[poneyrunner]

it is a dohc cluster.. like i was saying everything on it works except for the speedo.. it acts like the speedo is not getting power..

[poneyrunner]

wow.. almost 40 views and no one has any ideas????

[csramotorsports]

check individual wires, ground etc.

[mastakilla08]

is it a HUD?? type cluster? maybe your speed sensor is bad if its only saying 0

[poneyrunner]

my car is not hud.. it was a 89 sohc hatch that i converted to a dohc motor..it cant be a bad speed sensor due to the analog gauge works perfectly.. unless the digital gauge cluster requires a different speed sensor.. ive never heard of any of them needing the different sensors. and the gauge digital gauge doesnt even come on.. everything on the digital cluster works except the speedo.. the speedo just stays blank.. and about the wires.. any idea which wires i should check? i tried to look at the fsm but im just not having much luck on understanding it..

[compactfean]

If you look at the back of the cluster there are 2 wires that go to the speedo. If I remember right the 2p is main signal. I made a detailed write up of the gauge cluster a few months ago, but yes, digital and analog use the same signal and if you have hud it splices off that main signal. The other signal to the speedometer is actually a converted signal that goes to the ecu. Both digital and analog have it and either way has nothing to do with the hud.

[poneyrunner]

ok.. so why would the cluster work in 2 other cars but not mine? and why would the analog cluster and speedo work perfectly in my car? is there another separate circuit for the digital speedo cluster? the digital speedo almost acts like its not even getting power.. where or what is your write up labeled as so i can look at it?

[compactfean]

Im on my phone so ill just bump it.

[poneyrunner]

thanks ill check it out..

[poneyrunner]

ok.. so i read over that whole forum.. only problem is that the one your talking about is an analog gauge.. I did upload that fsm for my car and tried once again to foollow it.. it does seem like there is a separate wire that inlluminates and makes the digital gauge work.. but i sure cant figure out which wire it is.. its soo confusing to me..haha.. i need someone to teach me how the hell to read that thing.. i really think its a wiring issue with my car..

[compactfean]

i just figured out your problem...i think. if you are using the analog sub harness for the digital cluster then the pin locations are different putting your signal wire somewhere else. you will rather need to re pin your analog harness or use the digital harness. look at section EL-39 through 42 and look at the difference between the heads up control unit and the analog pinout. the easiest way to get that working is to just get the harness for a digital cluster. it disconnects far back on the right side but for sure thats your problem if your running the analog harness.

[poneyrunner]

no.. i have the digital gauge harness.. as a matter of fact i have 2 of them... i knwo there is a different sub harness you cant plug in the analog harness to the digital gauge at all..

[compactfean]

Are the wire colors the same and in the same spots on the plug that plugs into the dash, as the analog plug?

[poneyrunner]

oh... i dont know.. ill have to go look at them..

[poneyrunner]

ok.. got them side by side and on the wires or plugs that plug into the dash harness they are the same colors in the same spot except for 2 wires.. the digital cluster has 2 extra wires which when traced go directly to the speedo... the extra wires are on the black plug are a light blue wire and a purple wire and they take up 2 blank spots on the black plug that the analog cluster has empty... the purple wire is right next to the pink and black wire and the light blue wire is right next to the gold and purple wire on the black plug.. if that makes sense..

[compactfean]

those two wires, when you fallow them up, do they go to the hud control unit plug? if so which pins are they? look at EL39 in the fsm to see what im talking about. if you can figure out which pins those wires are than it will tell you what they are for on that page. unfortunately that page doesn't have any color codes for the wires...just pin location.

[poneyrunner]

ok the el-39 page in my fsm that i have is for the headlights.. here is the on ei have.. is specific to 89..
http://www.nicoclub.com/FSM/240sx/1989/1989.pdf

[compactfean]

Is the digital cluster an 89? I would use whatever wiring. Info for what ever cluster you have

[poneyrunner]

i have no idea what year the cluster is.. i really really dont think its the cluster.. all clusters are the same for all s13 styles other than the tach. that is why you can typically take any cluster and put it in any car that is an s13.. coupe/ hatch... 1989-1994.. like i said the only difference is suppose to be the tach.. if you have a dohc you have to have a dohc tach and same for sohc.. i some how didnt hook something up on my car when i did my conversion.. that is why it doesnt work on my car.. what i didnt hook up i have no idea.. that is why if i can find what wire goes to the speedo power .. (if there is a separate power wire for the digital speedo) then i can trace it back and make sure it has power and ground.. i really think that is the problems here.. i just dont know what wire to look for under the dash for the power and ground to the digital speedo... what is really the puzzler for this whole project is that the analog gauge works perfectly.. and everything on the digital gauge works great except the speedo.. thats what doesnt make any sense.. thats why i think there is a separate power wire for the digital speedo lcd that is not on the analog gauge that i dont have hooked up in my car.. so what i need to look at is the dash wires on my car which is an 89 from a car that has digital cluster that is an 89 or the fsm that shows the separate wires.. so i can trace down the different wire..

[compactfean]

ok, so lets look at the differences of the analog and the digital wiring. also let me get this right? the speedo doesnt have any reading on it what soever? not even zeros?
#1 the analog claims to have 5 wires that go to the speedo, power for the speedo motor, ground that goes back to speedo and common ground, speed sensor input, and speed sensor output to ecu, and if you look at the pin out and wires on the actual analog cluster and wiring the 5th is missing (so not applicable)
#2 the digital speedo has 7 wires. a common ground a speedo ground (its probably the same ground), speedo signal, speed signal to ecu, battery power, acc power, and ign on power.
so with that being said i can figure this out for you if you give me the info i need. if the speed sensor and digital speedo use the same ground like the analog does than there are two extra wires that the digital speedo use. so i need know to if pin 1,5,or 7 are missing a wire on your digital harness.
also i need to know which pins those extra wires go to. i am guessing it is rather pin 4,10, and or 11 because the digital speedo has 2 extra power supplies than the analog. but i need you to know for sure what pin number those 2 extra wires are and then i can tell you how to wire it.
all and all those wires are rather powers or one could be a ground......just nee the pin locations.

[poneyrunner]

yes your right about the speedo.. just stays dark.. ill have to check on the cluster.. i traded it last night due to i have another non working one for some other parts i wanted.. ill see if i can figure out what your talking about and try to find you the pin location so that when i get my other one working i can put it in my car..so you want me to look at what pins that the extra 2 wires go to? and i didnt even notice it but my buddy did i guess there is one wire as well that is a different color.. i think the wire was an orange and black wire ill make sure later and let you know.. i traded it figuring it would give me time to really figure out what is going on with this thing and get it fixed.. but like i said i have another cluster that the speedo doesnt work in any car.. im going to repair it and use it..

[compactfean]

you see how the hud control unit shows the plug with numbers in it in fsm? I need the numbers where the 2 extra wires go.that will tell me what they are exactly for.also I need to know if pin 1 5 or 7 is missing a wire.