So I bought a code tester and when the computer start testing stuff, I only hear the fan once.
The two speeds are applied quickly, one right on top of the other, then both off, so it's hard to detect them both and they seem like one, but at least you've confirmed computer control and basic ICRM & fan operation.
If you want to test fan speeds independently, you can pull the connector at the fan and probe each with a volt meter, then retest, or...
- Find/pull the IRCM and temporality remove the connecter so you can identify #14 & #17 wires - they should have tiny #s inside... Once identified, replace the connector back onto the IRCM. No need to reinstall the IRCM now, but be sure it is mounted when finished.
- Turn the ignition switch on/to the run position.
- Ground wire #14, the low speed fan should come on (relay and fan connector etc. ok). Leave #14 grounded.
- Next, ground #17 and the high speed fan should come on. If it does, the relay etc. is good.
You can stick a straight pin thru each wire, with jumper leads attached to ground them. Add a dab of silicone to the wounds to close them up when done.
If the relay checks out, it is not being triggered, but I think you've already confirmed that is ok, so if no joy with either speed, the relay and/or that circuit inside the IRCM has failed.
But again, the code tester check will run them both back-to-back very quickly and you may have trouble noticing one from the other.