Speed warning buzzer

[owner 84]

Hi,

Can you guys help me how the speed warning buzzer works on the classic trucks? My 1983 truck has one, but it is not working effectively because one of the wire sensor plugs is missing. The issue I couldn't find it or discover where it is coming from.

I saw this tube, but it is for 67-72. I believe the idea is the same.

http://youtu.be/OD3gS4RFQWE

[walkerb]

Never heard of a speed warning buzzer. Free bump

[Rubble]

Ya,I been driving these trucks since 1981 & this is the first I have ever heard of it.Had a couple that were only a few years old then,3 year old 78,3 year old 83 & 3 year old 85, plus lots since then & none had a speed warning buzzer.Maybe it's a U.S. thing eh??

[andrewmp6]

You sure its not like a seat belt buzzer or left the headlights on buzzer?

[too much stuff]

Last speedwarning i know of was in 69. Some of the bigger truck dashes had an "overspeed" light that would come on, but not sure about a buzzer.

[old Rusty C10]

I had this on a 73 buick le sabre I had.. there was a dial you set on the speedo that once the needle crept past this setting a buzzer would go off... by 84 I would think they had changed the system to something more electronic and like others have said, I don't ever recall seeing this in any of my trucks... is it possible that this is something aftermarket that could have been installed by a fleet or municipality?

[gchemist]

The only warning I get in my truck is when my kuckles are white and death grip on the steering wheel. Plus the speedo is wrapped around and straight up and down on the odometer.

[owner 84]

Hi everyone,

I am sorry for the late response. Actually, I forgot to say that I am from the Kingdom of Saudi Arabia. Most of Chevy/GMC trucks/pickups in that region have the speed warning buzzer installed. Also, the speedometer we always have there is in Km/hr. I will post you a vid of a 1986 C25 GMC truck that has been stored and it has low milage. This truck has the speedo warning buzzer.

‫??? 86 ?????‬‎ -...

[owner 84]

Those pictures are form the ebay

Here is pictures of the sensor where should be attached at the back of a speedometer.






here is one from ebay with speed sensor attached



see where the speed sensor is connected



My truck has the same thing. I have the yellow wire missing, and I do not know where it is gone!!! I need to know WHERE this yellow wire is coming from, so I can rewire a new one. The other white plug, which has three wires(red, black and white, and browny), 2 of them will go the the buzzer and the third one will go to the fuse box.

[owner 84]

[owner 84]

I nee to know what is the yellow wire!!

[owner 84]

This buzzer is for the ignition key or seat belt.

1985 GMC Suburban 2500 4x4 for sale - YouTube

[owner 84]

This is the speedo warning buzzer that is connected to the three wires speed sensor

[owner 84]

[owner 84]

I am doing my best, so you guys can explain or clear it up for me. I hope these picture explain what I aim to.

[gchemist]

My '83 had the same green sensor. It's a cruise control opto sensor. If a buzzer was attached, it probably work in conjunction with it.

[Ski-me]

I'll do what I can. I converted my cable speedo to electronic and had to mess around with the speedo input.

http://coloradok5.com/forums/showthr...g+cable+speedo

Here's a lot of pics and a write-up.

when I did it, here is what I found:

Pink (12V Ignition)
Black (Ground)
Brown (ECM input)
Yellow (Cruise input)

[owner 84]

My truck has manual 4 speed shifter which does not have Cruise from the factory, so do you think the yellow wire has a different function?

[Ski-me]

I don't know the pulses for each wire, but from my write up, it looks like both wires send out a 2000 pulse signal...but I would guess the brown one goes to your ECM and the yellow may be just stubbed off (from factory). Perhaps this is the one used for your speed warning buzzer?!?

[Ski-me]

After studying your pics, it looks like the buzzer is piggy backing it's power from the buffer module and using the pink and black wires for it's 12V power. Then it's taking the brown signal from the buffer to interpret the speed.

I don't know when the alarm/buzzer will go off but it must be driven by this signal and goes off once it reaches a certain pulse/power.

The yellow most likely is there "if" the truck is equipped cruise control. Otherwise, it may be just stubbed off.

I don't know if your 83 had some type of electronic spark control that used the brown wire ?!?

Anyways, if you are not getting a consistent behavior on your buzzer, maybe a few things:

- The buzzer is bad or whatever controls it to go off, is breaking down (maybe a diode or something?!?)
- The speedo cable is starting to stick and perhaps your speedo needle is bouncing around. This could cause the pulse from the back of the speedo to not be a "100%" smooth pulse.

When my speedo was bouncing around because of the cable, my cruise control didn't work very well. I "think" it was because the cable was bouncing around.

It also made my transmission not work correctly either due to the torque converter lockout (uses the pulse for ECM).

Anyways, just my thoughts....

[esbstuff]

At what speed does it come on at? Or is it adjustable?