Ok. Symptoms: Boost gauge rarely works, and when it does only has approx half the value it should. Can be made to work at this half value level by whacking the side of the dash, so I figured there might just be something loose / obvious in there for me to look at. No such luck. Now I'm not interested in anybody telling me to get an aftermarket boost gauge. Can anyone recomend a testing procedure for the gauge / circuit board etc itself? I realise it's probably getting a wee bit technical... but thought I'd try.

 

Are you for sure it's your boost gauge and not your boost? jk, mine did that for a while then I just spent some money and got a good Autometer boost gauge.

good luck

 

haha. me 1, annoying electrical gremlins 0.
After an hour or so of fiddling with the thing, searching the web, and scratching myself, I decided it was time to see if I'd fixed it without doing anything. Yup. Ignition on, boost gauge straight to 0. Happy with that one. Bye for now

 

Loose white circular connectors on the back of the combination meter or loose srcews on the back of the combination meter or loose screw in the drivers seat (humor).

 

I had the same problem with my '87 TII. I removed the gauge cluster. On the back is a printed circuit board. The contancts for the boost gauge are screws that go through the board and into the gauge. I cleaned under the screws and tightened (several were loose). After that my gauge worked perfectly for 1.5 years until I sold it.

Todd