Mapped out wiring harness for UB3

[Hairdo12]

Hey, I am bench testing my ub3 cluster and for those of you who would like to know what each wire does here is what I have found so far. Some of them I am unsure of and they are noted with a "?". So if anyone would like to fill in the blanks it would be great! The biggest question I have is this: My book says the tach signal wire is white, however there is no white wire on the harness.

the stuff in the ( ) is what is what you would connect to the wire to turn on the device during a test. Please fill in the blanks if you can.

 

 

D16 Orange ?

D15 Dark Green Speedometer (pulse to G)

D14 Black/White Ground (G)

D13 Purple Fuel Gage (hold to G for 40 seconds)

D12 Green/White Temp Gage (G)

D11 Tan Oil Gage (G)

D10 Brown/White ?

D09 UNUSED

D08 UNUSED

D07 UNUSED

D06 UNUSED

D05 Brown/White SES (G)

D04 Brown Charge light (G)

D03 Yellow/Black Low Coolant light (G)

D02 Yellow Fasten Belts (G)

D01 Black Ground (G)

 

 

C16 Pink/blk HOT (+12V)

C15 UNUSED

C14 Black/White Ground (G)

C13 orange ? this has a 5v charge when grounded

C12 Black Ground (G)

C11 Gray Odometer/Back light (+12v)

C10 Yellow ? if this wire is grounded the cluster shorts out

C09 UNUSED

C08 UNUSED

C07 Light Gray High Beem (+12v)

C06 Tan/gray ?

C05 UNUSED

C04 Tan/White Brake light (G)

C03 Dark Blue Right Turn (+12v)

C02 Light Blue Left Turn (+12v)

C01 Pink/Black Hot

[1990lumina]

Great info!

Hopefully some people can fill in the blanks for you!

 

- Jeff L.

[Dirty Rockstar]

C06 Tan/gray- Actually tan/black- ECM Shift indicator

 

C10 Yellow- VF Dim enable- (This allows dimming of the cluster when you hit the lights)

 

D10 Brown/White- VF Dimmer input (Variable lights when lights are on)

 

D16 Orange- ALDL Connection (Tells the Tach where the redline is)

[Hairdo12]

Nice info Davis, where did you find that i searched this site for hours

[Dirty Rockstar]

Well, a complete pinout of the UB3 install can be found here:

 

http://www.w-body.com/

 

Navigate on the sidebar to Upgrades, then down to electrical, then over to Instrument Panel Upgrade 8)

 

EDIT: WAYYYY TO GO in editing yopur post AFTER I did mine, Davis.. lmao.. JK

[Lee]

Different GM companies differ in wiring. My Regal does not have the same pin-outs as a Supreme.

[Baddflash]

D16 Orange- ALDL Connection (Tells the Tach where the redline is)

 

It also runs the tach too.

[tester239]

Hey w-body.com folks.

 

I'm a digital gauge fanatic. I don't own a w-body car, but i do have a set of digital gauges out of a cutlass supreme. These were apparently made by denso electric, not gm's delco...so trying to see how it works by opening it up, is not an easy task.

 

Anyway, on to business:

 

I see that you folks have the pinouts for these clusters on this site (which saves not time because i found this place after i figured out the pinout on my own lol.. but according to your listings, the tach is controlled by the ECM. Does this mean, it just goes right into the same line as the ALDL? because I was wanting to remove the display module and put it into my s10 Blazer... but without a tach, it makes it useless to me. If it runs off the ALDL datastream, i might be able to install it into my Blazer.

 

BUT.... your pinout says "bi-directional" as in the cutlass uses the 8192 baud bi-directional data stream used in OBD II, which wouldn't make any sense since OBD II wasn't used on GM vehicles until 94, and the cluster is from the 89-91 era.

 

Thanks for any help In the meantime, i'll head out to my blazer and hook it up to my aldl line, and see what kind of things i can burn up S-Series A/D Conversion: http://mtx.mine.nu/s10

[GP1138]

OBD II wasn't used on GM vehicles until 94

 

Actually, it wasn't till '96. It was basically OBD 1.5 until then.

[stockgp]

so why not just use the blazer digital cluster? weren;t some of them available with a tach?

[tester239]

well i do use the stock digital dash, i just think the one in the cutlass looks nicer since it has the circular speedo.

 

installed the digital one myself: http://mtx.mine.nu/s10 ......

[stockgp]

i see. well i have to agree the cutlass cluster is better looking

[tester239]

so yeah, my blazer uses a C3 ecm. it only has a 160 baud one-directional serial data. so the gauges can't send requests to the ecm for engine data. what I don't understand is if they have that stupid line for the tach data, why not just do it for all the other data. i mean, all you'd need then is a single line to the ecm, then the t/s input and power and some other misc stuff, and you're done. i guess 8192baud isn't fast enough.

 

now, i wonder if it's possible to install a newer ecm into my blazer and just put in my old engine data chip.....wow, sounds like a lot of work for a gauge cluster but it must be done!

[GnatGoSplat]

8192 baud isn't OBD II, the 8192 baud ALDL is actually very old, used in P4 ECMs which date back to the late 80's. I don't know why the Blazer would use an old C3, that's what a lot of GM cars got in the early 80's, but who knows with GM.

OBD II uses Class 2 which is some PWM format.

 

I don't think a C3 and P4 are compatible, you'd need a special chip for that engine. P4 uses a MEMCAL and I think C3 just uses a PROM.

 

Anyway, I know of someone who has gotten it to work with a regular tach signal by using a programmable microcontroller. That's probably a steeper learning curve than figuring out how to install a newer ECM though.

[tester239]

the C3 was used until about '93 on S10 trucks/blazers/jimmys. I looked at a 94 jimmy and a 94 bravada, and it looked like they had the P4 ecm..but i couldn't tell for sure.

 

I didn't realize 8192 wasn't OBD II.. hmm, learn something new every day and I guess I have a archaic engine computer too

 

according to my s10's service manuals, my v6's computer has a prom and a calpak. but if I had a L4 engine, it would have a memcal just like the newer ECMs... i might just have to go take my computer out and have a look..