Rocketbrian

I have a 70 safety sentinel speedo which needs a repair to the little hair spring in order to operate correctly. Before I think of having it repaired, I was wondering what would be involved in order to have it operate in my 71 442. I know it's not correct, but I thought it might be a neat novelty item to have. This speedometer has five pins on the back instead of four on the regular speedometer, so is it easily possible to wire it up so it would operate? Anybody tried this? Thanks.

oldspackrat

The hi beam headlight lens needs to be changed from red to blue. There should be a 3 legged buzzer that plugs into 3 female plugs on the back. I'm not sure about that 5th pin on the back. I don't know where it gets power from? Maybe it show in the assembly or service manual? Other than that, it should be plug & play.
Here are a couple pix for reference.

Allan R

I'm curious to see what you find out. I also have a 70 speedminder speedo (works) but want to restore it before plugging it into my 72. Like you I just like the idea. Possibly the extra pin is the power feed to the buzzer (relay)

I can't find it in the 1970 electrical schematic or the 1970 CSM??

Allan R

Looking at Scott's pics it appears the center pin is the power pickup for the relay. The other side of the relay appears to ground out through the casing.

Scott, can you post a pic of the backside of a 71 or 72 speedo? I'm not worried about the high beam indicator color...

oldspackrat

Allan R

Thanks Scott! I'm now sure that's the power feed for the relay. Shouldn't be terribly hard to wire an extra pin into the existing harness and tap into power.

Rocketbrian

Thanks for the help guys. Allan, now that I have you motivated to try this upgrade, I'll await your results in tapping into power to run the buzzer, before I send my speedo to Redline. I love it when a plan comes together.

tdhill01

I'm interested to know the results too as I have one for a floor shift - can the speedometer mileage be reset to what's on my original speedometer easily?

oldspackrat

If you're somewhat mechanical, the odometer can be set to what ever you want. There is a little paper keeper that holds the numbers in place, you have to be careful not to damage that or your're in trouble. If you have some extra speedos, you can practice on those. If not, I can send you a rough one to play with.
Scott

Allan R

Yes, here's a how to video that shows what to do. It's for Mustang, but the speedo on Olds is basically the same.

oldspackrat

Thanks Allan!

tdhill01

Thank you both for great information to help me along.

Rocketbrian

I got my tic toc tac back from Redline Instruments, all repaired and cleaned up. A great guy to deal with. The coil in the circuit board was gone. He had one and fixed in in one day and sent it on its way. Great friendly service. My point to all this, is that I spoke with him about these speedos and he says he can repair mine and that I should consider sending it to him for refurbishing. He says they can be finicky to set up, but doable. The little hairspring on mine is broken and stretched, but I tried the buzzer with power and it buzzes, so it may be worth doing. He says they are quite rare and a very desirable option with the last one he had selling for $450.

tdhill01

Thanks for the update. Are you going to send your speedometer in to them to get it repaired? I would have to weight the cost compared to what it could be worth in the end. Even if the buzzer does not work it still is a neat gauge to have in the dash.