Remember those wonderful reverse style gauges that we recently had made? Well I decided to install a new set on my spare gauge cluster I bought off ebay for 150.00 (145 mph speedometer). Ok so I am getting everything ready and I am like hell I might as well take of the gauge needles and paint them red. After that I am like oh ya the guy I bought the gauge cluster from said the odometer didn’t work so I decide the swap odometer parts from my original working cluster.

To make a long story short after tearing apart my car I finally got the thing installed but my tach and speedometer don’t work… So I am like hmm were is that smoke coming from… Apparently I fried the little removable green board on the left side. **** take it out… Hmm lets put the other cluster in… Now my car is chiming continuously and won’t stop and my right light does not work anymore on either gauge cluster. The chime is extremely annoying it now runs continuously even when the engine is running.

I checked my fuses and they are all good. Any suggestions besides not working on my cars electrical system again?

On a slightly brighter side note the reverse indigo gauge overlays and red needles look very good…
I seriously fuc?ed up my car…

Remember those wonderful reverse style gauges that we recently had made? Well I decided to install a new set on my spare gauge cluster I bought off ebay for 150.00 (145 mph speedometer). Ok so I am getting everything ready and I am like hell I might as well take of the gauge needles and paint them red. After that I am like oh ya the guy I bought the gauge cluster from said the odometer didn’t work so I decide the swap odometer parts from my original working cluster.

To make a long story short after tearing apart my car I finally got the thing installed but my tach and speedometer don’t work… So I am like hmm were is that smoke coming from… Apparently I fried the little removable green board on the left side. **** take it out… Hmm lets put the other cluster in… Now my car is chiming continuously and won’t stop and my right light does not work anymore on either gauge cluster. The chime is extremely annoying it now runs continuously even when the engine is running.

I checked my fuses and they are all good. Any suggestions besides not working on my cars electrical system again?

On a slightly brighter side note the reverse indigo gauge overlays and red needles look very good…

 

Is it the chime that comes on like when the doors are open, lights on, etc? You might could disconnect that, I'm not sure about the light though. Also, don't work on your cars electrical system again.

:lala:

 

Well I got really pissed and pulled out my soder gun and now I belived/hope I have everything working expect for my right blinker light. Why would only my left blinker light not work? Additionally does anyone have any tips on how to re-callibrate my gauge readings?

 

I just installed a z28 gauge cluster into my 1992 RS and the speedometer is not working correctlty. The speedometer acts as if it was my original speedometer that only went to 110 with a 145 mph face on it. For example when it says I am going 80 I am actualley going somerwer around 60.

Do I need to have something else re-callibrated for the new speedometer to read the correct speed?

Or I am I experiencing this problem because I fried the little green board near the speedometer and had to replace it with the one from my old gauge cluster.

I really dont know so if you can help it would be appreciated.

 

Did you replace just the gauges or are you using the full circuit board as well?

The Z28 circuit board is different from the RS. They may plug in the same, but the wires in the plugs will have to be switched to the proper pins.

A friend tried swapping a Trans Am dash into a Firebird and had the same problems.

You will have to find a schematic for the two boards or trace each connection route.

 

Grr...

Are you saying that the printed and soft circut board on the back of the gauge clusters are different for z28 and rs? Or are you saing that I may have to re-arrange the pins that the gauge cluster plugs into?

So far I have gotten everything working exprect the speedometer thinks it only goes to 110 and it really goes to 145.

 

I'm not sure about the circuit boards not being the same (never heard of that). And if it's already working, just not the right speed, I think you're close to having it work. I know in a cable driven speedo, you have to change the gear that drives it to get it to read the right speed. I don't know if you'll have to change your sending unit, or pickup, or what. I really don't know much about that sort of thing.

 

All I know is that its not cable driven unit...

 

I asked a friend about it... I don't know how accurate this is... But here is what I was told.

The speedo's went from cable driven to electronic but the tranny's stayed the same. Instead of a gear and a cable, you have an sending unit on the tranny. Your's will need to be replaced with the sending unit of a car that came with the higher speedo.

Once again, I have no idea if this is right or not... I'm sure someone on here knows about that. I might would put a post in either Trannys or Electronics, or both. I hope this helps some.

 

i had this problem when i changed rear end gears. if you car is like mine. A 1992 Chev Camaro RS. you have a electric spedo that connects the the VSS (Vehicle Speed Sensor). It's located on the tail housing of the transmission. in there you have two gears the drive and driven gear. you can probuably changed those to get the right speed you need. Just to let you know the gears cost 5 dollars each from GM. you might want to ask some one here what they have or would do but i think this would help but i don't know what combo you need.

 

Well I have bad news. The green circuit board DOES control your speedometer. The guages are what they call "air core guages". For that, an "air core driver" must be used. That air core driver is what smoked on your little green board. How do I know this ? I smoked one by mistake too

What really sucks is that the drive is a GM ONLY application made by Texas Instruments for GM. There's two chips, one right next to each other. One is a little PIC controller that controls the white chip which is the air core driver. Well this PIC is what controls the rate of movement of your speedometer. IF the PIC didnt burn out on your Z28 (145mph) board, you can take it off that board and solder it on your RS board. Yes, THIS chip is the only difference between the Z28 and the RS boards. No, this chip can't be bought anywhere unfortunately.

You can either do that, or just buy another 145 mph cluster. Or if you get lucky, you can probably snag one out of broken cluster in the junkyard or something.

 

Is what your refering to the hard green board that sits under the speedometer inside of the gauge cluster, because thats exactly what I fried.

Additionally what does the one little "PIC" controler you mentioned look like? Could you possibly post a picture of give detailed instructions on how I can determine what part it is and if its still working on the z28 board?

Do you know if their are any differences in the little green board on the right that sits under the tach?

 

Here are some pictures of the green board in question (the one I fried).

<img src="http://www.fhbconcepts.com/harold/speedo_greenboard-1.jpg">

<img src="http://www.fhbconcepts.com/harold/speedo_greenboard-2.jpg">

 

Someone please help...

 

Sorry I guess I forgot to follow up on the thread.

The chip with the white sticker on top of it is what the we call the PIC. That's what different between the RS and Z28 boards.

I can see from the pic that you blew up the air core driver. I did the exact same thing. LOL I have an extra one that I know works. This is an impossible to get item since I said it was manufactured for GM by Texas Instruments. It's a custom application unfortunately

The other side of the board (aside from the two chip and the crystal) is what drives the little motor that spins the odometer spools. That usually never goes out. Does that still work on your car ? Beacause if it does , then the PIC is still good.

 

I just tried to remove the "PIC" from the z28 chip and ended up destroying it. I guess I need a better sodering iron.

Do you have an extra z28 chip that you would be willing to part with? If so how much do you want for it and how soon can you ship it.

 

I know this is a old post, but it is some good info on the cluster and one reason why they quit working.


I had smoke coming from my speedo the other day. It smelled burnt on the back of the cluster also.

My question is, if I am running carb with no ECM and at th350 with no VSS, would 12v still be running to the speedo?

Also would it be ok to still use the cluster like it is with the board burnt out?
I dont use my speedo anyways, but would it cause any other issues?