High temp buzzer ???

[acarlson]

So, according to the '65 wiring diagram there is a high temperature buzzer under the dash. Also, it looks like there should be 2 wires coming off the engine temp sensor - one which connects to the oil pressure sensor (blue wire) and the second (red wire) which connects to one of the connectors of a two connector plug.
See below - I have deleted non-essential wiring and added my own color code to the wires.

wire1.jpg (45.36 KiB) Viewed 609 times

The red green wire (my color) goes to the dash temp/pressure indicator light. The red wire (my color) goes to the buzzer. This is my understanding of the wiring schematic.

I have the two port connector (indicated in the schematic) for these connections in my engine wiring harness.

However, my engine temp sensor only has the wire which jumpers it to the oil pressure sensor (blue wire, my color). This spliced wire plugs into the connector which goes to the dash temp/pressure instrument panel light. The second connector (for the buzzer) is not connected. This all works, assuming that there was no buzzer to begin with.

So, now my questions:

(1) Was the buzzer for the Corsa an option or standard equipment ?

(2) If there was such a thing, where under the dash would I find it ?

(3) If it was removed, what could I replace it with ? I see Clarks has one but it's pretty expensive for a buzzer... Seems like any 12v buzzer would work...

Alec

[notched]

All 65 and 66 Corsa models will have the wiring for the buzzer, but only turbo models would have it installed. It is located to the left of the steering column and above the high beam switch.
Typically the wires are pink and green. The buzzer is actually a relay.........similar to the horn relay. Same buzzer was used again as a key in ignition warning buzzer on the 68 and 69 models and on 67-69 Corvairs with the Speed Alert option. All late models have the dimples in the panel for the sheet metal screws that retain it. I have found that many times that buzzer is rusted away from the windshield leaking onto it.
140 Corsas typically have the connector tucked in or hanging.
Is there a possibility that the dash harness was replaced with one from a Monza?

[cnicol]

Hi Alec,
The buzzer was only installed on turbo models. 140 models had the wiring but the factory did not install the buzzer. As I recall it was located high on the cowl more or less above the e-brake handle. I'm pretty sure my '66 Turbo has one still if you need a picture.

Your wiring analysis isn't quite correct. On Corsa models, the oil switch and temp switch are isolated and individually wired up to the dash area. The temp switch wire goes to the temp buzzer and then to a diode in the harness and then on to the TEMP/PRESS light. The oil sender is wired directly to the light (no diode).

The reason for the diode: Every time you turn on the key, there's no oil pressure so the TEMP/PRESS light comes on. Without the diode to block power flow to the buzzer, the buzzer would also sound every time you turned the key ON. The diode prevents Corsa Turbo owners from going crazy!

[bbodie52]

Wiring diagrams for both the Corvair Spyder and the 1965-66 Corvair Corsa are shown below. Both cars use a single warning light (TEMP/PRES) to alert the driver of either an oil pressure fault or a high cylinder head temperature fault. By default, the oil pressure warning sensor (switch) is closed when there is no oil pressure, or when the engine is not running. This allows the light to be tested by illuminating the bulb when the key is turned to the ON position, but before the engine has been started.

The silicon rectifier (diode) in the circuit prevents a circuit ground from the oil pressure sensor from causing voltage to reach the buzzer — causing an audible alarm. But if the cylinder head temperature switch in the right cylinder head was to close (triggered by very high cylinder head temperature) the warning light would be illuminated AND the buzzer would sound. In reality, I have been around Corvairs since the early 1960s and I have yet to see that warning light ever triggered by high cylinder head temperature. As long as the fan belt is intact and is circulating cooling air over the cooling fins on the engine the engine will essentially never overheat. However, a broken fan belt can cause the engine to quickly overheat and be damaged. By the time the warning light from the right cylinder head would actually be triggered the damage to the engine would likely already have occurred. So on the Corvair instrument panel, the GEN/FAN warning light is critically important. The other warning light is essentially there to warn of a no oil pressure condition, which is rare. The temperature portion of these warning lights (that includes a warning buzzer on turbocharged engines) is of little use and will probably never be activated. The cylinder head temperature gauge on the Spyder and Corsa is much more useful to monitor engine temperature.

Corsa TEMP-PRES Schematic Details

The high temperature buzzer and silicon rectifier in the Corsa wiring schematic can be viewed using the following link…

Corvair Combined Wiring Schematics
http://www.corvairforum.com/forum/viewt ... 25&t=12968

[acarlson]

Actually, I was thinking I'd hook the buzzer up to the alternator light - I just needed to know if I had one and where it was located. Since it was only available on the turbo model I'm out of luck - my car was originally a 140 4x1. A previous owner replaced the 140 with a 180... Still, I have the wiring for it so I may see if I can hook up some aftermarket alarm...

Alec