63 Giulia Tri gauge problems & questions

[L.MCKEOUGH]

After many hours fooling around with the temperature gauges I finally got them working. Now these are actually Giulietta gauges in my 1963 ( actually built in 1962) Spider. I kept changing the sensors but that turned out not to be the problem. I finally removed the gauge from the dash after carefully marking all the wiring. Once on the bench I connected a battery charger and started testing everything. The only things not working correctly were the two temp gauges. I took the front off the tri-gauge and removed and cleaned everything. As you can imagine, there are actually three separate gauges inside the tri-gauge and I removed them all. I then took the face off the oil temp gauge and revealed the two small magnetic coils inside. One of these coils has a small tab on it which is supposed to make a connection with the side of the casing. I could see that it wasn't touching the case so I took the case off the gauge and bent the tab up slightly. When I replaced the case it was making a good connection. Then I put it back together and re-connected the battery charger and like magic, IT WORKED. I had the sender in the circuit on the bench putting it in a pan of boiling water and then adjusting the coil set screw (on the coil without the little tab) until I had a reading around 190 deg. I then did the same thing with the water temp gauge. Once I installed it all back in the car I had both temp gauges working properly. My low level gas indicating light is operating properly but the gas gauge level indicator is still not working. The gas gauge has the same tab on one of the coils and I made sure there was a good connection to the case. But still won't work.The gauge reads full when not grounded. Once connected to the sending unit it gets grounded and then reads empty. I think the sending unit is actually bad. I'll keep you posted.

Larry McKeough

[Gordon Raymond]

Excellent job Larry. You deserve 4 stars! Too many people fear working on these old instruments with the honest fear that they may break something. The problem is less likely for the concerned diagnostician like yourself. Work carefully and slowly, and learn how these things were supposed to work. Only on the newest solid state stuff requires rocket science. That is why I try to limit my work to pre 1968 unless I am very familiar with the diagnostics of the newer models. Again, good job, and well explained! Thanks!

[pathung]

I think I'll dig up my Sprint's unused tri-gauge to understand it a bit better, and hopefully fix the one in my Spider. Thanks for the excellent write-up, Larry!

[dbest]

Larry, The cork floats for the fuel sending unit in the tank are notorious for sinking. If you find this to be the case it is possible to replace the cork with a plastic float from a 105 series sender although you must ensure everything stays in alignment for the gauge to read correctly.

Regards,
Don