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I am new to SRF. I bought a car last Dec. I did my school and first race with no issues. Oil temp maxed out about 217.5 based on the AIM data. I did the school and 2 races in 3 days but I don’t think it got above 60F outside.

I went back to the same track this weekend but it was around 75f late afternoon. I started getting an intermittent LED warning after about 20 miles. The warning was for high oil temp. Data showed 231.8. I checked all the connections and changed the relay for the oil cooler fan. The next day morning sessions were in the low to mid 60’s and the oil temp maxxed out about 221. The afternoon session was 70 and it was back at 231.8. Any easy troubleshooting or thoughts? Water temp is running 160 to 170 at speed and oil press about 45.

Thanks in advance.

Oil cooler fan
I think the ECU is programmed to turn it on at 217. Maybe something failed in the fan or wiring since your last outing.

Yes, listen for the fan whirring away to your right when driving back to your paddock spot. If not, get into why.

If you're running synthetic oil, it's formulated to withstand temps way higher than that. NASCAR Cup cars run north of 230 regularly. That said, it's a good idea to keep water and oil temps normal to maximize engine performance.

You may want to make sure the thermostat is operating correctly.
To test, insert a blade of a zip tie at the throttle stop for fast idle. The thermostat should open around 195 degrees.

You can manually trigger the Oil Cooler Fan using the PE software as a diagnostic test.

I run Mobil 1 Synthetic Racing oil so I think I didn't hurt anything. Water temp was around 170 when rolling. The highest oil temp was 233 on the data plot. I unplugged the harness and cleaned the plug for the relay and also cleaned the plug from the oil wire. Is it ok to put dielectric grease on the relay prongs to prevent corrosion?

It was 80 the following day and I ran 3 twenty minute sessions. The oil temp went back and forth between 206 and 215.6 on the data plot so it looks like the fan was working after the reseating and cleaning. I don't think it was ever working before. Just my first weekend was cold outside so the issue never showed up. Thanks for the ideas.

You should be fine especially with the good water temps. On really hot days, you'll be seeing oil temps above 217 regularly.

I discovered an oil cooler fan issue. Traced it (with Jisu's help) to the "white" wire back to the ECU. Does anyone have a diagram of the pin assignments in that big master connector?

The Oil Cooler Fan Relay signal is Digital Output 05 which is pin M-05 on the large connector.

To complete the picture for digital outputs,

The ECU lamp is Digital Output 09 which is pin M-25 on the large connector
The Fuel Pump Relay signal is Digital Output 10 which is pin M-06 on the large connector

I have not found this documented anywhere.