Speed Marker Harness?

[Coolerman]

I removed the Speed Sensor from my 12/70 and coiled the wires under the brake master. They came out the firewall there. My wires ran from the Speed Marker, through the firewall, then down along the speedometer cable (mine was hanging loose) and connected directly to the sensor. There was no extension cable.

I can take pics tonight if you want, maybe pull back the cover on the wires?

Yes. pics would be great!

 

[Coolerman]

What kind of signal do these put out and how many pulses?

From what I could tell when testing mine, the speed detector puts out a sine wave. This is fed to a circuit that converts it to pulses. Once the pulses reach a certain frequency (related to a certain MPH ) it triggers the VSV.
I do not know the frequency of the pulses but their amplitude is quite low.

 

[srgould41]

Ok Coolerman, here are the pics of mine that I promissed. My wire colors are not what I expected, red with black. The wires come through the firewall just outboard of the clutch master and break out of the loom about 8" lower down as you can see in the last pic, sort of

Hope this helps. Let me know if you want more pics or something.

 

[Coolerman]

I believe those RB wires are for the column mounted reverse switch for the three on the tree.

The wires you need to look for are Blue with a white stripe. I'm not sure when the Cruisers came with the speed marker. Maybe yours never had it?

I do appreciate the pics though!

 

[srgould41]

Oops! You are right. I swapped to a floor shift and had to rewire the switch. DOn't recall how I did it now... Hmm. Serves me right for trying to take pics in the dark at 10 pm, hurrying so I can get to bed. Let me look at it again after work today.

I believe those RB wires are for the column mounted reverse switch for the three on the tree.

The wires you need to look for are Blue with a white stripe. I'm not sure when the Cruisers came with the speed marker. Maybe yours never had it?

I do appreciate the pics though!

 

[Martyt]

Old thread Coolerman but I think my 69 is original regarding the speed marker and related speed detector (related to the emissions) and the wiring. Am sure you probably found your answer in the past 9 years.