Intermediate cadillac value

[11DG]

Hello, everyone. Iv noticed my trucks cadillac valve will start cutting in and out sporadically. I can drive it for a little while and everything is fine. Then the fan clutch trys to engage and then stops. Over and over agian it tries. As it's failing to decide to engage or not the temperature starts to climbing. This is the second time it's done this, in both instances it occurs after 45 minutes or so of steady driving. Im in a parking lot waiting for it to cool. Thanks for the help guys.

 

[Mogman]

Unplug the wires to the valve, this should give you 100% fan on to get you home.

 

[11DG]

Yes I'm aware of that, but none the less thank you. I let the truck cool down to about 180° give or take. Then drove it home with no issue. Which is exactly what happened last time. I suspect, perhaps the cadillac valve is over heating. After shut down it was rather warm. Be advised "rather warm" is entirely subjective, I'm a welder by trade so my hands are heat treated.

Separate symptom? I noticed this odd sound from the same region of the valve. A sort of chittering sound. Like a squirrel with a cough. Noticed it three times today. Twice in the morning and once this afternoon, both in my driveway. During low RPM and high steering imput. Power steering pump under mild load influencing the valve. Don't know, got somethings to do this weekend.

Thanks again for you expedient help.

 

[HoveringHMMWV]

Also, check the harness wires. Mine were chafed and initially gave either full time fan engagement or sporadic engagement irrelevant of temperature. I repaired the chafed section and ops normal now.

 

[Mogman]

That valve making noise is rather normal, some folks go to great lengths to make it quiet including wrapping it in rubber which I would be afraid would make it overheat.
it will be hot as the hydraulic fluid from the brake/steering system is constantly flowing through it, 180 deg or so would be normal

 

[11DG]

I did go through the wires this past weekend. I found that switch wire 458A was not fully seated. Fixed that, then started through the -10 and 20-1 for everything related to cooling. The TM wanted me to bring the truck up to operating temperature to test resistance of the switch. In that case I'll just drive it down the road. By the end of my road she hit 220° and the fan engaged fine. That last time she did it I was 200 meters from the house. The fan was hiting and missing like crazy.

 

[11DG]

That valve making noise is rather normal, some folks go to great lengths to make it quiet including wrapping it in rubber which I would be afraid would make it overheat.
it will be hot as the hydraulic fluid from the brake/steering system is constantly flowing through it, 180 deg or so would be normal

Oh no no my friend, I know that sound. I'm a chronic gauge watcher. So the fan cutting on is never a surprise. What it does is, attempt to engage the fan, which it does but only for a moment. Fan turns on then off again. Or it will do a half hearted attempt. I.E. the annoying hissing stops but the fan doesn't engage, then the hissing comes back. After a little while of driving the truck it will fluctuate rapidly between those two occurrences. Either and at random, engage fan then immediately disengage. Or attempt to engage the fan, fail, and give up. It will do it continuously, over and over agian it tries to engage the fan and fails. All the while the temp gauge slowly climbs. This is not normal operation.

 

[Mogman]

Oh no no my friend, I know that sound. I'm a chronic gauge watcher. So the fan cutting on is never a surprise. What it does is, attempt to engage the fan, which it does but only for a moment. Fan turns on then off again. Or it will do a half hearted attempt. I.E. the annoying hissing stops but the fan doesn't engage, then the hissing comes back. After a little while of driving the truck it will fluctuate rapidly between those two occurrences. Either and at random, engage fan then immediately disengage. Or attempt to engage the fan, fail, and give up. It will do it continuously, over and over agian it tries to engage the fan and fails. All the while the temp gauge slowly climbs. This is not normal operation.

Unplug the valve and see if the fan runs all the time, if so it is likely and electrical problem with the temp sensor, TDM or the wiring.

 

[Hummer Guy]

My last cadillac valve done this same exact thing, about 2 weeks later, either it gave out or something else, that cause the fan to turn 100%. I decided to do away with that whole crappy system and go to the viscious fan clutch setup, can't wait to see how it does. No more failing TDMs, Cadillac Valves, or leaky hydrualic fluid from the quick disconnect

 

[11DG]

Unplug the valve and see if the fan runs all the time, if so it is likely and electrical problem with the temp sensor, TDM or the wiring.

I shall try this, tomorrow. Thank you.

 

[Retiredwarhorses]

I shall try this, tomorrow. Thank you.

you are aware that truck has a switch to deny 24v to the Cadillac valve solenoid….if the fan wasn’t engaging “meaning it had continuous power” , why didn’t you just flip the switch which is the same as unplugging the TDM or the Cadillac valve? This would have allowed you to just to just drive on.

 

[11DG]

Yeah, I know, I just wanted to try and catch the truck doing it while I was under the hood. Which of course, it didnt want to any more. Besides, I pulled into an apartment complex and suddenly all the young woman decided to walk their dogs at the same time. So that's cool. But any ways, iv chased the whole circuit and the only connection I haven't found is 785B. Which disappears over the top of the front diff and then into the netherverse. I assume it goes to the temp sensor under or around cylinder 1 IIRC. I just haven't consulted the TM about it yet. At this point I'm inclined to think it's a tired TDM.

The other noise I noticed, I had wrongfully attributed to the cooling system. I did a bit of light wheeling this morning. And have determined it's definitely something in the front driver suspension/drive line. I haven't been able to isulate the exact circumstances that cause the noise. I suppose I'll just have to throw my chassis ear on it and drive circles in the yard.

Right now I'm going to install the guard dawg RFID system.

P.S. Hi Steve, nice to see you agian. I hope everything is going well for you.

 

[11DG]

My last cadillac valve done this same exact thing, about 2 weeks later, either it gave out or something else, that cause the fan to turn 100%. I decided to do away with that whole crappy system and go to the viscious fan clutch setup, can't wait to see how it does. No more failing TDMs, Cadillac Valves, or leaky hydrualic fluid from the quick disconnect

Sorry, I didn't see you post. If your cliam is correct then it could be my valve. Truthfully im considering going to a viscous clutch as well.