The digital displays (speedo/tach bar)in my '85 Berlinetta are dead. Both vacuum fluorescents are out (everything else works fine), leading me to believe the power supply for these died. I just got the cluster connector pinout last weekend, and would like to get a set of schematics for the I.P. cluster 3-board set.

Also, what is the spec on the tach signal. The speedo signal looks like it should be a 5v square wave (I'm assuming a 50% duty cycle), from the buffer assembly. But I can't find anything on the tach signal. I haven't had a chance to hook up a scope to the connector input yet.

I just got the car 3 weeks ago (with the dead dash), and I'm having a blast!

Thanks in advance for any help!

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Dave Cieske

'85 Camaro Berlinetta 305 Carb'd, Auto

 

I have not seen any schematics for the 3 board set, however, you may want to verify that the dimming input to the cluster is functioning properly, as this may completely dim the tubes.

The tach signal is driven from the switched leg of the ignition coil, so it is a (very noisy) 0 to 12 volt signal.

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Tim

1992 Z28, 305 TPI 5 speed, 12.1 sec @ 114.7 mph

1984 Berlinetta 305 TPI Auto, 13.8 sec @ 99.7 mph

 

Thanks Tim. I don't believe that it's the dimming input - everything else on the dash does dim properly. Also, the shop manual states that the turn indicators do not dim, but always stay at full brightness. That's the part that is driving me nuts! I can live without the speedo for a while, but it's really embarrassing to drive down the left lane for two miles with the signal on, just to see the reflection in the car ahead of you! Gotta laugh ...

Thanks for the tach info. It helps.


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Dave Cieske

'85 Camaro Berlinetta 305 LG4, Auto

 

You may want to reflow all of the solder joints in the display driver sections of the board. John in RI (berlinetta@prodigy.net) sells Berlineta parts & may have a digital cluster for sale.

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Tim

1992 Z28, 305 TPI 5 speed, 12.1 sec @ 114.7 mph

1984 Berlinetta 305 TPI Auto, 13.8 sec @ 99.7 mph

 

Talk about timing! I just pulled the display tonight, and plan to go over it tomorrow. Good idea on re-flowing the joints. I get so caught up in looking for bad parts that I forget the basics. I'll drop John a line, and see what he has. Can't hurt to have a spare.
I MIGHT have a line on schematics for the boards. If it turns out good, I'll get you a copy. Thanks.

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Dave Cieske

'85 Camaro Berlinetta 305 LG4, Auto
'67 Grand Prix Convertible 400, Auto

[This message has been edited by Dave Cieske (edited October 15, 2001).]