Boost Guage Doesn't Work


New Member
They say there are no dumb questions. Okay here's one.

I've got a straight stock 87GN with 15K miles on the OD. Just got it this year and drove it only a few times. Idiot lights, but has the electronic tach and boost guage as I think they all do. Tach works fine but no boost guage readings whatsoever.

I was at a Buick club event and one of the guys who knows more than me took a quick look and the wires seem to be connected okay. Is there something that commonly fails that I should be looking for?

Was only able to pull off one decent run 14.12 @ 97mph, with a terrible RT of 1.3. Was my first race in about 15 years. All the rest of the runs just smoked the (original) tires trying to launch off the tach at about 2K.

Any ideas how to trouble shoot this would be appreciated.
The MAP sensor may be bad. It's on the passenger side, inner has a thick rubber connector with a 1/8" hard plastic vacuum line going to it. You might chase this line down and see if it's broken somewhere....or the MAP sensor itself may have failed. BTW this doesn't provide any feedback to the just sends a signal to the stock boost gauge.

I wouldn't get too excited about it since the stock boost gauge is notoriously inaccurate. It is also very common for the electronics part of the gauge to be fried by hooking up the two connectors over by the alternator. Behind the alternator you'll find two connectors that APPEAR like they should be connected together, BUT DON'T CONNECT THEM. The green one is a tach output for diagnostics and the other is a power feed to the fuel pump so you can test it. If they are connected together it will fry your dash's boost gauge and the tach.

Hope this helps,
Thanks for that info, John. The internet (and these Buick boards) are so amazing. Ask a question and get an answer in just a few minutes. It's like the giant big head of knowledge. And open for business 24x7.
Casper's Electronics ( ) can fix the stock LED's but as already stated they are notoriously inaccurate to begin with ( the guage NOT Casper's! ;) ) I'd recommend going with a good aftermarket guage ASAP!

Doug C.