'87 firebird, LG4, does the cruise signal come directly from the buffer box? Referencing http://www.hioutput.com/tech/speedo.html , I have an extra pink wire, don't know what that is for, I didn't see a pink in the cruise harness...

Anyhow, the speedo works fine, I had to rewire the signal to the gauges to come directly from the 4K out of the ecm, but cruise does not work...wondering if the modulator itself is bad. It has vacuum and everything else...

There is a small small tear in the rubber boot on the outside, this isn't the actual diaphram is it? I didn't feel any leak around it.

Any help?

 

Hm, well I disconnected the vacuum line from the cruise unit and plugged it...guess what happened....pig rich. Looks like its probably the tear in the diaphram.

Thank you myself.