Help identifying broken cable under car

[armand80sc]

Was looking under the car today (1980SC) and noticed this broken cable on the right side.
Can anyone please identify the cable and its function? Does it have to do with heating???

Also if anyone has pictures of the speedometer sensor location underneath the car that would be most appreciated.

[DRACO A5OG]

heater cable, check one of your levers inside the cab.

you can buy some nickle plated steel cable at ace hardware

[James Brown]

you see the silver cable about a inch from the broken silver cable on the heater box ( the red rusty thing) thats where it goes and it is attached to the black thing by the white thing. looks like you need a new heat box. at least remove it (them) and clean them up. might have caused the cable to snap, all rusty and such. There should also be a spring that pulls the louvers open when you push down on the lever in the car

[armand80sc]

Thank you guys for the quick + helpful advice! Another project to add to the list

[armand80sc]

For the benefit of others, just found an extremely helpful write up in the Tech articles section regarding the heater boxes :
Pelican Technical Article: Heater Box Replacement

[schumicat]

the speedometer sender is a brown plastic disc on passenger side of the transmission, held in place by a piece of spring steel. has a wire running into the car. pretty easy to find.

[Walt Fricke]

Speedo sender is a bit above and forward of the passenger side CV joint, so it is easy to spot. Has a black covered wire (actually, two wires in one sheath) coming out of it. The spring clip is held in place with a 10mm head bolt, which you should loosen to move the clip. The end of the speedo sensor wire is a connector inside the car, back in the center tunnel by the access panel (4 phillips screws) for the transmission shift coupler. There is a rubber grommet on this wire which gets it through a hole in the chassis into the tunnel in the vicinity of the torsion tube.

Before you go pulling out the speedometer sender, do these two tests:

1) Pull the speedometer out of the dash. The signal wire, as I recall, is green, and you can pretty easily differentiate it from the wires for the lights, the grounds, and the positive wire to the instrument. Pull the signal wire off. Attach a jumper wire to the speedo signal wire lug. Turn the ignition on. Tap the end of the jumper wire rapidly onto a chassis ground. If the speedo is working, you should see some movement of the needle. More movement the faster you tap.

2) You can check the sender circuit easily with an ohmmeter. With the rear of the car up on jack stands, and the signal wire detatched, connect the meter to the signal wire (not the speedometer), and to ground. Rotate the right rear wheel - either put car in neutral and have someone turn it. This is best, as you should see the ohmmeter needle or digital readout change from infinite/nothing to 0 ohms or a very low ohm number eight times per wheel revolution.

This is because the sensor is a magentic reed switch. Each time one of eight magnets attached to the differential housing passes the sensor, it closes (or opens - I can't recall which). When open, you get infinite resistance. When closed you get whatever the resistance is in the wires and reed switch contacts (which isn't much).

I suppose you could also put the transmission in 1st, and start the motor and let it idle - I've not tried that so don't know if you would see the on/off/on/off signal as well at any RPM as well as you should be able to see it with hand turning.

No signal from sender and speedo needle moving some with the tap test tells you if it is the sender which has gone bad (or there is a break in the sender signal line, or the ground line from the sender, which goes all the way back to the speedometer to connect to ground.

[NoYouRelax]

Here is a picture of the speedometer pickup on the transmission. Ignore the dirt, oil and grime, I made it go away.

[NoYouRelax]

Also, I have a spare heater flapper wire I can part with. PM me if you need one

Bill

[armand80sc]

Thank you for the pics and advice regarding the speedometer sending unit - I managed to find it But I should probably continue the discussion on that topic in this thread which I originally started.
1980SC Speedometer Problem