Help: Need Part

cjoenck · 07-15-2009, 09:08 AM

I can't find a relay R44, part number 964.617.117.00 - it is called temperature control relay in PET and I can't find it anywhere. Pelican Parts can't locate it and I am hoping someone out there has a spare to sell. Thanks

kurquhart · 05:44 PM

Did you try Sunset? They have been able to get parts for me that Pelican was unable to.

group911@aol.co · 07-15-2009, 05:38 PM

I should have one from a parts 964.
E-mail me at group911@aol.com and I'll check tomorrow.
Thanks

cjoenck · 07-20-2009, 03:22 PM

So the mystery continues. It seems the US 964 does not have a relay R44 installed. "Group911" checked 5 cars for me and there is no R44 in any of them. In the meantime I had contacted Sunset - at the suggestion of kurquhart - and at first they were as confused as anyone. In the end Jeff found that relay R44 is used in RoW cars and it is superseded by part number 993.617.119.00 but can be used in the 964.

So the question remains: Why does the wiring diagram show R44 in use even though it was not installed in US bound 964s? I will order the part through Sunset to see what it actually does. The puzzle continues.

Thank you for the help. This really is a great community.

Chris

crg53 · 07-20-2009, 04:36 PM

Just a wild guess, but could it be the DAYTIME RUNNING LIGHT relay?

Don Settergren · Don Settergren's Garage

According to my shop manual, R44 is a Thermo Switch for Catalytic Converter. Maybe heat is more of an issue in the ROW than the USA... (see upper-right of photo)

group911@aol.co · 07-21-2009, 10:30 AM

And obviously, even if you install the relay, there isn't anything on your car for the relay to control.

cjoenck · 07-22-2009, 07:03 AM

I am looking at the same wiring diagram. Btw, it is not the day running light relay - there is a different slot for that. If I read this right, relay R44 actually drives the oxygen sensor heater. The oxygen sensor needs a pretty high operating temperature before it becomes accurate. So, in RoW cars, the sensor is heated until the temp sensors reads an exhaust / engine temperature that is close enough to the required operating temp for the oxygen sensor. I know the US cars don't have this but I guess my engineering mind really would like to understand this. Call me obsessed

Chris

38D · 07-22-2009, 02:37 PM

You can always jump the relay to see if it does anything

lucittm · lucittm's Garage

R44 is used in the catalytic converter monitor circuit for RoW cars. The purpose of R44 is to light a lamp in the clock by routing a ground from pin 5 of R44 to bulb #10 that has +12V already connected via fuse 18. The bulb shows the driver that the catalytic converter is at an improper temperature. The USA cars do not have the temperature sensor and do not need the thermo switch.

Thanks,
Mark

cjoenck · 08-10-2009, 03:27 PM

Thank you Mark, that makes a ton of sense. It's just not evident from the wiring diagram I was looking at. Still begs the question why this was omitted on the US cars - not that you could do a whole lot about a wrong cat temperature. I guess you just get the info that your cat is working sub-optimal.

Thanks again for all the help

Chris