2005 5.0 Me cruiser TKS Enrichment Module/Solenoid NO Power

[WannaBMechcanic]

PTI,
Looking for some input here... I have a 5.0 TKS ( NO Choke Carb) and the Enrichment Solenoid ( brand new) is not getting the 12V to engage... Anyone know were that voltage might be coming from? I have read the oil pressure sensor but no voltage at the pin there.. However, my oil pressure gauge seems to be working ok. I can apply 12v to the module and it will engage.. so need to trace it back.
TIA!

 

[alldodge]

The enrichment solenoid starts closing down once power is applied. When cold its open and provides more fuel to the motor until it heats up from power. If its not closing down then it may be bad.

Power comes from the ignition switch and thru the diode to TKS. After about 10 minutes it should extend and close off the port. You can apply 12V direct to the plug connector to see if it does work to troubleshoot

 

[WannaBMechcanic]

The enrichment solenoid starts closing down once power is applied. When cold its open and provides more fuel to the motor until it heats up from power. If its not closing down then it may be bad.

Power comes from the ignition switch and thru the diode to TKS. After about 10 minutes it should extend and close off the port. You can apply 12V direct to the plug connector to see if it does work to troubleshoot

View attachment 360810

Thank you for the reply... As mentioned.. Module is brand new and it works fine if I apply 12v to it.. NO Problem.. Maybe the diode is bad and not allowing voltage through. I can test the diode if you tell me where to look for it?

 

[alldodge]

The diode resembles a long rectangular fuse kind of thing. Its not that big and ,see page 2 on the pdf

 

[WannaBMechcanic]

Alldodge, So I have done much testing with my multimeter.. At the connector I get my 12v needed with the boat on, ground is good. HOWEVER, as soon as I touch or connect the positive side I lose my 12v. SO whatever, where ever the positive side of the 12v is coming from it must be faulty and can't handle the draw. SO where is the positive 12v coming from?? Ground is good.. I can leave the ground as is and Jumper the Positive from else and all works as it should.. I hope this makes sense..

 

[WannaBMechcanic]

Alldodge, So I have done much testing with my multimeter.. At the connector I get my 12v needed with the boat on, ground is good. HOWEVER, as soon as I touch or connect the positive side I lose my 12v. SO whatever, where ever the positive side of the 12v is coming from it must be faulty and can't handle the draw. SO where is the positive 12v coming from?? Ground is good.. I can leave the ground as is and Jumper the Positive from else and all works as it should.. I hope this makes sense..

Diode is bad... Also found TKS 15A fuse blown.

 

[alldodge]

Diode is bad... Also found TKS 15A fuse blown.

Good deal
A shorted module can take the diode and fuse out. Having a new module you should be good. If fuse blows again then its the temp switch grounding out

 

[WannaBMechcanic]

Good deal
A shorted module can take the diode and fuse out. Having a new module you should be good. If fuse blows again then its the temp switch grounding out

One more question.... you say temp switch could be grounding out... when looking for parts as such the names are different. One shows up as a Sender and the other one is a Sensor.. So which one is the Temp Switch or is the Temp Switch something completely different? Thank you!

 

[alldodge]

One more question.... you say temp switch could be grounding out... when looking for parts as such the names are different. One shows up as a Sender and the other one is a Sensor.. So which one is the Temp Switch or is the Temp Switch something completely different? Thank you!

Look on the intake manifold item 10
https://www.mercruiserparts.com/bam/subassembly/31841/11741/90

 

[alldodge]

And to verify its not shorted, measure ohms from each pin to engine block