Installing A Regal Instrument Cluster in a Centruy

[jase.ch]

Hi,

Have a '99 Century. Has anyone successfully swapped in a Regal Instrument Panel and got it to work out?

Thanks,

Jason

[Imp558]

That's an interesting one, if it's not a plug-in it's got to be close. And welcome to the community. 

[digitaloutsider]

Same car, same plug. It will work.

[jase.ch]

Thanks for the welcome! Installed a 2003 Regal panel this AM with no problem so far. Unfortunately gotta get the ODO reprogrammed from the 150 now showing to the original 51k. Trying to figure out the cheapest way to do it.

[vipmiller803]

I know the century one has no tach. The new one's tach works fine? GM really kept that century as unsporty as possible back then.

[Imp558]

From a manufacturing point of view it's more expensive to make a harness for each application. So I figured it was the same between both vehicles.

A dealer or a garage with a Tech II may be able to fix the odometer reading.

[digitaloutsider]

The Tech II cannot overwrite the cluster mileage in the Regal. It's written to a non-user accessible portion of the memory on the board. 

I'm not sure what the gauge cluster rehab people do, I assume they have to completely remove the EEPROM and reprogram it with whatever mileage it needs.

[Imp558]

Really?  I always assumed it could be fixed with a dealer tool.

If a car had a bad speedo they would be incapable of fixing it. 

Of course that would be just one more dealer service deficiency on a list of many so it wouldn't be outlandish. 

[digitaloutsider]

GM's Service Manual used to state that a sticker was supposed to be put on the driver's door listing the old mileage and the date the cluster was replaced.

[vipmiller803]

I doubt you can program any counter chip to a specific number, but it would be feasible to find the chip responsible for the odo and resetting it to zero. Then it'd be a game of playing catch up. Some here have done it using a waveform generator running for a few days.

[jimmyfloyd]

I seem to recall that a new cluster could be programmed to a higher mileage, but once set, that was it. Definitely no going backwards. 

[Imp558]

One has to wonder if it's feasible to solder the old eeprom into the new clusrer.

That may be worth playing with some day. Or reading the eeprom and trying to manipulate the HEX file.

[jase.ch]

It's been scorching here today and noticed that the temp gauge goes from low up to 1/2 when the engine turned off. Been running at just below 1/2 as usual while driving. Didn't see that with the Century cluster which remained at low with the car off. Any Regal owners see this?

[Imp558]

Different needles rest at different points, if you don't like it the temp gauge from the Century would likely swap right in.

A GM instrument cluster is far from being accurate instrumentation but it sounds like it's behaving when powered.

[digitaloutsider]

The Regal/Century temperature gauge is really a suggestion that you're either overheating or not. If you're concerned about it, hook a scantool up and see what it's actually doing.

As long as it works fine when the car is running, I wouldn't worry about it.

[jimmyfloyd]

On 8/6/2018 at 2:31 PM, Imp558 said:

Really?  I always assumed it could be fixed with a dealer tool.

If a car had a bad speedo they would be incapable of fixing it. 

Of course that would be just one more dealer service deficiency on a list of many so it wouldn't be outlandish. 

https://www.ebay.com/itm/97-04-BUICK-REGAL-INSTRUMENT-CLUSTER-SPEEDOMETER-ODOMETER-REPROGRAMMING-SERVICE/192444637556

 

looks like there is someone on ebay who can do it, so it has to be programable someplace

[White93z34]

If you were to learn the location of the EEPROM that stores the milage you could likely swap them between boards if your soldering skills are good.

[jase.ch]

Seems like the easiest fix. Someone know where the eeprom location is for both the Regal and Century? Google not helpful. I think it's an 8 pin chip though.

[Imp558]

Write down all the numbers and google them. Desoldering an eeprom is not for the faint of heart though.

The guy on Ebay for  $60 is a pretty good deal, not so great aftersshipping I suppose.