Issue with Boost gauge on 86 GN Digital dash

[Richbel]

Ok guys need some input. Last week I purchased an 1986 Grand National. 31000 miles unmolested down to the original paint and interior. The boost gauge in the dash cluster did not work when I bought it. I drove it home aprox 3 hours. About an hour into the trip, when going uphill, the gauge started to work when the turbo kicked in

, but just lit up yellow. It worked all the way home. since I've gotten it home last thursday, it doesn't work again. I haven't done anything to the car yet, as its going for a tune up tomorrow. Any Ideas where to start, without tearing the dash out?

 

[Heskahoka]

Search is your friend here on this site, especially for a new user . In this case I did it for you.
I entered "digital dash boost lights" into the search bar in the upper right part of the screen.

Here is a result I got which might help:
http://www.turbobuick.com/forums/threads/turbo-boost-lights-on-digital-dash.229420/

Good luck, looks like a nice, unmolested car.

 

[GNVenom]

I have repaired hundreds of digital dashes from turbo Regals. With almost no exception, the inoperative lamp issues I have seen have to do with the lamp sockets attached to the flex board behind the cluster.

The sockets corrode at the point where the lamp terminal meets the socket terminal due to the dissimilar metals. I have seen hundreds of lamps inoperative, but only a handful of actual burned out bulbs.

This article explains the problem:
http://www.installationinstructions.com/FYI/alternator_charging_tech.pdf

 

[85supreme]

I had a similar issue. Check the hose going to the waste gate solenoid. Mine was completely rotted out so boost was never actually registering half the time. After I replaced it I solved my knock issues and my boost light issue. Hope this helps.


Sent from my iPhone using Tapatalk

 

[GNVenom]

Check all the hoses. The boost switch on the passenger side fender well has a long plastic tube, subject to going brittle and cracking. Several places a vacuum leak can show up.

In fact, plan on replacing all vacuum hoses within the engine. You will be surprised in how many of the hoses are cracked.

 

[salvageV6]

Actually there isn't a problem at all, the two idiot lights, (not a gauge), only work when you hit about 4psi. and then 8-10 psi. boost.

The round dual pressure switch on the passenger fenderwell with the hose on it sometimes has the contacts corrode if not used it can be adjusted under the rubber caps on it.

 

[Richbel]

Thanks for the help guys, no issue with the dash at all. Bad hobbes switch. Replaced it and now they light up perfectly.

 

[Heskahoka]

Good to hear. Thanks for reporting back your solution.

 

[Boostian]

Thanks for the help guys, no issue with the dash at all. Bad hobbes switch. Replaced it and now they light up perfectly.

Where'd you get one from?

 

[Richbel]

Ebay. 32.00 junk yard

 

[CzyKats44]

Anyone know the part number? Mine is corroded on the bracket.