72 GS 350 with factory gauge cluster. Where does your needle lay at normal operating temp? What is the resistance reading at the sending unit at normal operating temp?
On my 70 it reads 2 hash marks below 1/2 way. It tends to go to the hash mark just below 1/2 on the highway if I run the engine at 3k for an extended time. On the 72, it reads about the same. If I put the AC on, it will go to the 1/2 mark in traffic. I guess it all depends on how the sender is calibrated. I don't have resistance reading for you. I never took any on either car. Would be interesting to compare though My best advice would be to install a mechanical water temp gauge in temporarily to see what "normal" is on the factory gauge. Then just remove it
Not in an A body but on the 430 in the Riv the factory gauge reads 1/4 when the mechanical is saying 190. The very few times it got to 1/2 or normal the car was over 225 and boiling. That was during my experiment with electric fans.Ive replaced the sending unit and got the same results.
All you would ever want to know about temperature sending units. http://forums.corvetteforum.com/c1-and-c2-corvettes/2189912-temp-sending-unit-problem.html Interesting stuff. Lou
Good info, thx!! It bothers me that my gauge reads so low and never seems to fluctuate, but it seems as its normal where is is- just off C
If the needle location really bothers you it can be fixed. You will need to add a resistor that will change the sender output to the requirement of the gage to read center. However it will only be accurate at that temperature and will be off on others. Pay your money and take your chance. Lou
Adding a resistor to the circuit in series would increase the total resistance therefore lowering the needle on the scale, opposite of what I would like. If I could add a resistor in parallel with the sender that would decrease resistance but would not be accurate at all because of the fluctuating value of the sending unit. Does anyone know of a replacement sender with a lower resistance value?
Seems like the nailheads always want to run hot. The ones I have gauges in I'm always looking at the gauge, whatching it creep up. The one with only idiot lights is more relaxing for me.
A lot of Nailheads have initial timing of 2 1/2* BTDC. If your vacuum advance is not working, or not connected to manifold vacuum, it will want to run hot from that relatively retarded timing.
Here is an event that occurred over the past couple weeks. My buddy owns a '67 Mustang with a '95 Ford 5 Litre (modified + fuel msd injection). After we arrived at a car show, two weeks ago, the engine overheated. After some diagnosing, we discovered that the fuse for the electric fan had smoked and ruined the fuse link. So we were able to find the parts at the show's swap meet and made repairs. Later that day, when he arrived home, the engine overheated again. So we replaced the thermostat + a new thermostat housing which allowed him to reconnect the temp gauge on the dash. Guess what? Yesterday, it ran hot again! I had asked him whether the electric fan, mounted to the aluminum rad facing the motor, was pulling or pushing. I knew it should be pulling the air thru the rad, not pushing the heat from under the hood out thru the rad. Well, he checked it out and low & behold the fan was pushing! Quickly swapped the fan connectors (had to replace one connector and all was well again! He had unplugged the fan connectors to clean and reconnected them wrong.
