Temperature Gauge not working - Volvo Penta 5.7 GI-E

[gilsaraiva]

Dear Community, I need help to solve my Temperature Gauge not working.

I already replaced the;

• Temperature Gauge
• Temperature Sensor

I already tested the;

1. 5v to the sensor (ECT) ( no problem)
2. 12 v in the gauge
3. ground the ECT sensor (engine coolant Temperature)
4. Wire from the Gauge to the Big Connector (PIN 3)

One piece of information that I'm missing and couldn't find is where PIN number 3 goes from the connector to the engine. Does it go to the ECM? Maybe this is the problem because I tried to find it via continuity test in the ECM J1 and J2 and had no success.

The engine is behaving fine, but I realized the previous owner removed the Thermostat because it couldn't solve this issue.

Thank you in advance, and please let me know if you need any information.

 

[alldodge]

Welcome
The gauge has at least 3 connections.
12V when key is turned ON
Ground
Sender wire going from the gauge thru pin 3 to sender

Remove the sender wire from sender. Turn key ON and ground wire, the gauge should peg Hot

 

[gilsaraiva]

Welcome
The gauge has at least 3 connections.
12V when key is turned ON
Ground
Sender wire going from the gauge thru pin 3 to sender

Remove the sender wire from sender. Turn key ON and ground wire, the gauge should peg Hot

Thank you for willing to help.

1- 12V working fine in the gauge
2- When I ground the wiring the sensor the gauge didn't move.

I'm still suspecting the wire from the female connector (picture) to the engine harness.

 

[alldodge]

Thank you for willing to help.

1- 12V working fine in the gauge
2- When I ground the wiring the sensor the gauge didn't move.

I'm still suspecting the wire from the female connector (picture) to the engine harness.

Agree, might also be the 10 pin connector. Have seen many times that the pins get corroded and some break away internally

Can check with ohm meter

 

[gilsaraiva]

Dear Community, I need help to solve my Temperature Gauge not working.

I already replaced the;

• Temperature Gauge
• Temperature Sensor

I already tested the;

1. 5v to the sensor (ECT) ( no problem)
2. 12 v in the gauge
3. ground the ECT sensor (engine coolant Temperature)
4. Wire from the Gauge to the Big Connector (PIN 3)

View attachment 402696

One piece of information that I'm missing and couldn't find is where PIN number 3 goes from the connector to the engine. Does it go to the ECM? Maybe this is the problem because I tried to find it via continuity test in the ECM J1 and J2 and had no success.

The engine is behaving fine, but I realized the previous owner removed the Thermostat because it couldn't solve this issue.

Thank you in advance, and please let me know if you need any information.

I just did additional tests that confirm the following.

The connection from the Sensor ground to the ECM - J2-7 (it's working fine)

 

[gilsaraiva]

Agree, might also be the 10 pin connector. Have seen many times that the pins get corroded and some break away internally

Can check with ohm meter

How should I test the 10-pin? Any Idea where can I find where the pin 3 goes to from the female connector (engine compartment)

Thank

 

[alldodge]

I just did additional tests that confirm the following.

The connection from the Sensor ground to the ECM - J2-7 (it's working fine)

Your mixing Temp sender and temp switch
The gauge at the helm uses the sender in your pic and goes direct to the gauge, it does not go to the ECM

Your motor also has a 2 pin temp switch that goes to your ECM (assuming J2-7). The temp switch closes when the temp gets to hot and sounds the alarm.

The temp sender and the gauge does not talk to the ECM, it's only there as a visual indication for the driver

 

[alldodge]

How should I test the 10-pin? Any Idea where can I find where the pin 3 goes to from the female connector (engine compartment)

Thank

Pull the connector apart

 

[gilsaraiva]

Temp sender and temp switch

Your mixing Temp sender and temp switch
The gauge at the helm uses the sender in your pic and goes direct to the gauge, it does not go to the ECM

Your motor also has a 2 pin temp switch that goes to your ECM (assuming J2-7). The temp switch closes when the temp gets to hot and sounds the alarm.

The temp sender and the gauge does not talk to the ECM, it's only there as a visual indication for the driver

oh man, Thanks a lot. Maybe is that! Let me try to find where is this temp sender.

I assumed that this ECT sensor works with ECM and give info to the gauge

 

[gilsaraiva]

Your mixing Temp sender and temp switch
The gauge at the helm uses the sender in your pic and goes direct to the gauge, it does not go to the ECM

Your motor also has a 2 pin temp switch that goes to your ECM (assuming J2-7). The temp switch closes when the temp gets to hot and sounds the alarm.

The temp sender and the gauge does not talk to the ECM, it's only there as a visual indication for the driver

I just came here to thank you again. You were right; I was mixing both, to be honest I didn't know the sender were there in the engine. I found the Temp sender, did the ground test, and the gauge is working fine, so I assume it's the sender sensor that has a problem. I already ordered a new one. As soon as I replace it, I'll post the results here.

 

[Fun Times]

You'll also need to ensure the engine is actually getting up to normal temperature in relative timeframe. A stuck open thermostat will make the gauge appear to not move keeping the engine to cold...

 

[gilsaraiva]

You'll also need to ensure the engine is actually getting up to normal temperature in relative timeframe. A stuck open thermostat will make the gauge appear to not move keeping the engine to cold...

Good point! I tested it, and it did not have the thermostat. The previous owner couldn't solve the gauge issue and removed the thermostat to prevent overheating.

I installed the thermostat and am trying to make this gauge work.

Thank you.

 

[gilsaraiva]

I want to thank everyone who helped, especially @alldodge, who realized I was mixing things up. I replaced the sending unit, and it's working fine now!