Numerical Oil Temp Guage Conversion

[Doug E]

I just "downgraded" to the numerical oil temp guage on my '81 SC and thought I'd post how I completed the job along with some helpful hints for anyone who is still considering doing this to their car:

1. Read project #90 in Wayne's book while the car is cooling down.
2. Disconnect the battery
3. If your guage doesn't just pull out, use a small old (ie, not sharp) flat head and work carefully around the outer rubber gasket to break that seal. Once that seal is broken then use incrementally larger flatheads until you have worked the guage out about 1/2 inch. At that point you should be able to pull it out.
4. BEFORE disconnecting any wires, draw a diagram of where everything goes. It is pretty simple but there are two red/black and green/red wires which you don't want to cross.
5. Carefully disconnect all the wires and bulbs and try and keep the connectors separate between the Oil Temp and Oil Press connections.
6. Once all wires have been disconnected, take the guage to the workbench and CAREFULLY slide a very small flat head through the top of the screws so that any of the original glue is pushed out. By not doing this you will run the risk of stripping the screw (which I almost did) because some of the glue is pretty deep.
7. Once the glue has been pushed out, unscrew each of the 4 screws, remove the original guage and slide in the replacement.
8. Tighten each of the 4 screws, reconnect the wires using your diagram from step 4 and slide the guage back in the dash.
9. Note: I did not slide the guage all the way back in because I want to make sure everything works OK just in case I need to pull it out again.
10. The sender unit can be hard to spot but it is just to the right of the lower pulley in between the AC belt.
11. Disconnect the wire attached to the tip of the sender unit.
12. Push a rag under the sender because some oil will come out when she is pulled.
13. I used a 19mm offset box wrench to loosen and remove the unit.
14. Be careful not to drop either the sender or washer, although you should probably replace the washer anyway (even though I didn't).
15. Screw in new sender unit and tighten (spec is 18.4 ft lbs but I couldn't get my torque wrench in there so I just did it hand tight and then cranked slightly with a 19mm open end wrench).
16. Remove rag and clean up any excess oil.
17. Reconnect battery and start car to look for any oil leak and then re-tighten sender if necessary.

Even though some people think this "downgrade" is a waste of money, I wanted to do it just so I knew exactly what the oil temps are. All in all this was a pretty simple project and total time for everything was just under 1 hour.

Hope this helps!