Water temp gauge t-shooting, advice needed (3 Viewers)

[45Dougal]

Actually .9 bar converts to 13 psi, .97 bar converts to 14 psi. The significates of psi is a higher boiling rate so for every psi (3 degrees for every 1 psi) which in turn can help prevent overheating. If the cap is too high (depending on condition of cooling system) it can lead to overflow, leaks, or damage

Numbers are with 50/50 coolant
3 x 13 psi = 39* above 220 for a sum of 259*
3 x 14* +42* .....262*

Done nerding out with Hazmat/O-chem stuff.

Is that Celsius or Fahrenheit?
Quick reminder that its a Toyota, so it was born with SI units, even if you guys weren't
Btw.. Sounds like the fuel gauge might need its regulator cleaning to me.

 

[Mark Jennings]

Is that Celsius or Fahrenheit?
Quick reminder that its a Toyota, so it was born with SI units, even if you guys weren't
Btw.. Sounds like the fuel gauge might need its regulator cleaning to me.

13.23 to be exact.

 

[firemanj92]

Fahrenheit

 

[Mark Jennings]

OK, we should get back to the Original Post….troubleshooting his gage cluster. I do not think your Motocraft Solid State voltage regulator is an issue….keeps the battery charged,….so that’s a plus. Nor do I think a solid state regulator will ‘buzz’….there are no moving parts. Your ‘buzz’ could be anywhere….

If you have a voltage drop to the cluster, chances are a dirty/corroded terminal or a poor ground. Personally, I’d vote on a ground.

 

[45Dougal]

OK, we should get back to the Original Post….troubleshooting his gage cluster. I do not think your Motocraft Solid State voltage regulator is an issue….keeps the battery charged,….so that’s a plus. Nor do I think a solid state regulator will ‘buzz’….there are no moving parts. Your ‘buzz’ could be anywhere….

If you have a voltage drop to the cluster, chances are a dirty/corroded terminal or a poor ground. Personally, I’d vote on a ground.

I'm thinking that buzz could be the fuel gauge regulator

 

[Mark Jennings]

I'm thinking that buzz could be the fuel gauge regulator

On 76, I thought they went to a resistance float. The ‘buzz’ type was change I think in 74….you’d have to ask @Living in the Past. He’s our model/yransition year expert.

 

[45Dougal]

On 76, I thought they went to a resistance float. The ‘buzz’ type was change I think in 74….you’d have to ask @Living in the Past. He’s our model/yransition year expert.

Im not sure, but my 77 still has a regulator in the gauge though, and after nearly 50 years it's getting
weary.

 

[Living in the Past]

On 76, I thought they went to a resistance float. The ‘buzz’ type was change I think in 74….you’d have to ask @Living in the Past. He’s our model/yransition year expert.

Certain things I know dates of a change over file sending a fuel gauge is not one of them. Quick search did show 9/72-1/79.sendind unit was was the same. 9/72-9/73 is a one year gauge. 9/73-1/79 gauge was the same. 73 was a transition year for the instrument cluster. Gauge mount changed 9/73 with the printed circuit board. Probably the reason 73 is a one year. Mounted like the old style gauges but values were style.

 

[procomsignathid]

I just replaced the the fuel sending unit when I replaced the gas tank, I'm not sure if I have a regulator for that or not. I purchased this one from City Racer. I have heard a buzzing coming from the passenger firewall, and Ive heard it in that vicinity when the hood is open. If its not the regulator, what do y'all spose it might be? I did just recently have to replace the battery, so I'll do some checks tomorrow to make sure the regulator is working as expected.

Either way, sounds like that might be a red herring. One of the things I don't understand when I look at the electrical schematics for the '78 is which terminals (referred to as B and C above in the FSM where I had a couple tests fail) land on the schematic. What would result in a varying voltage between 2 and 7v?