Cat 297C heater

[Russell McBain]

My 297 had a new motor put in, and I believe they turned off the water from going to the heater core. I've looked for the valve to turn it back on and cant seem to find it. theres one hose that goes to the inlet in the motor, the other goes to the radiator. Neither have a valve.. please help.

 

[Nige]

Usual question - Serial Number.?
That lets us look at the parts setup for the heater lines to see where the valves are.
Did the heater work OK before the engine was changed and when did you last use it.?

BTW you posted in the wrong section but don't worry I asked for it to be moved.

 

[Russell McBain]

Damn.. sorry, I knew that. GCP01201

 

[Russell McBain]

Yes, heater was good.

 

[Nige]

There are no manual shutoff valves on the heater lines at either end.
You have the electrically-operated heater valve mounted right next to the heater core. Start tracing power to that starting with Fuse #A3 (marked HVAC blower) would be my first suggestion. If you want an electrical schematic just ask.

 

[Russell McBain]

Ok, Thank you.. just sat down for leftover turkey, I'll get out this afternoon and check that out.

 

[Russell McBain]

Nige, would it be a good guess that the AC switch on the overhead consol is what opens or closes that valve?

 

[Nige]

Nige, would it be a good guess that the AC switch on the overhead consol is what opens or closes that valve?

No. it comes from the variable temperature control switch, via a resistor, to the water valve.
Electrical schematic on the way. Check your messages.

 

[Russell McBain]

Nige, was a little delayed in getting into trouble shooting.. 10 days of sinus/ear infection..
traced everything to the heater core, there isnt a valve for heat/air. its been removed and the coolant has been bypassed from going to the core. Meaning , nothing flows to the heater core. Someone bypassed behind the motor somewhere.. i'll try and get into finding out what was done in the next week. Any chance you'd have the proper routing of the heater hoses?

 

[Vetech63]

its been removed and the coolant has been bypassed from going to the core.

That happens when the core is leaking and someone doesn't want to fix it.

 

[Russell McBain]

Yep, they clearly didn’t live in the north..

 

[Nige]

If you get into the heater assembly I suggest to first see whether the core holds pressure. Not sure if you might have to de-gas the A/C to get into the assembly. Maybe someone else can comment on that.

I’ll look for an illustration of the heater lines.

 

[Russell McBain]

Looking at the cores, they look separate .

 

[Nige]

Looking at the cores, they look separate .

I understand that, but to get at the heater core in order to replace it, if that's what you finally have to do, MAY require the A/C core to come out as well which could possibly necessitate de-gassing the system.

See the attachment. It should have everything you need. If not please ask.