aim 412 has a pic of the speed warning system. I have my buzzer and harness out now. My question is, why are there 3 terminals on the buzzer and only 2 wires in the 3 holed connector?The top tang connects to an empty hole in the connector? Just curious about that one. Also, I have the original speedometer out and my question is, on the back , the lower screw of the two that hold the gauge into the dash panel had a black ground wire connected to it of approx. 4 inches length, not connected to anything else. My speedo worked as far as keeping track of speed, but I dont see this ground wire anywhere in the AIM. Is this original? I dont think it has anything to do with the speed warning system because I didnt see it in the AIM

any info/help appreciated

looks like the top prong on the speed warning buzzer is not used and there is no connector going to it. ( AIM) They used a three hole connector just like the generic dimmer connector available from AAW ( american auto wire), but didnt put a terminal in.
Maybe that buzzer has another use where they do use the top prong? I have no idea...


According to AIM ac diagram ( excellent diagram if you have a/c!), regarding the diverter door switch, the green lone wire goes toward the firewall and the two tan wires which are on the same terminal go the pass seat side. I used two single connectors and used black porpatch after mild dremmel grinding to rough up the sides and put them together to form a perfect match for the melted connector.

Melted fan speed connectors ( 2 different connectors, both 3 way black, top and bottom. The lone 3 way low blow switch connector on the other side of the heater /ac controls is grey) :
I ended up using a generic dimmer three hole connector to replace the bottom fan switch melted connector. I cut off the center top part, and porpatched a single connector on top over the left botom connector to match the prongs. It looks just like the melted one , but its not melted lol.

This was relatively inexpensive to bring back my ac harness and vacuum controls. I inspected the terminals and wires and they all cleaned up nice. My three way vacuum hoses all cleaned up nice too. I used laquor thinner, then mineral spirits, then marine clean and water. I was amazed how they came out.

I have the original speedometer out and my question is, on the back , the lower screw of the two that hold the gauge into the dash panel had a black ground wire connected to it of approx. 4 inches length, not connected to anything else. My speedo worked as far as keeping track of speed, but I dont see this ground wire anywhere in the AIM. Is this original? I dont think it has anything to do with the speed warning system because I didnt see it in the AIM

any info/help appreciated

I only know of two original ground wires in that area, one is for the Headlamp switch and the other is for the Instrument Cluster ground to the dash.
They both go one the same screw attached to the dash.
Maybe someone replaced the lamp switch or worked on the dash and knocked it off the switch bracket abd installed it in the wrong place. Look on the bracket the switch attaches to and see if one is going there.
Other than that, maybe it's just a left-over from some past accessory someone installed ...

btw - my 68 also has speed warning and the buzzer has the same three wire connector with only two wires in it - one is power from fuse-box and the other goes to connector on instument cluster.

thanks for the confirmation on the buzzer. This wire is an extra ground and it was in addition to the normal one which was attached correctly. It was attached to the speedometer's lower hold in screw with the correct screw and the washer thing in the hole had its imprint on it. What is strange is that it has the exact same original gm ground terminals used on the normal ground nearby and it would fit right into that same hole on the metal part of the dash and ground plate if it was connected. Since it is an original part and obviously old ( the top of the terminal is semi hex shaped like the other ground), I'll probably put it back but leave it unatached just like it was. I think there it was a factory mistake or is to something I dont know about yet.