Thanks Ken for posting the schematic. Lot different than the generic Haynes schematic.

Looks like the motor will run when hi-speed (4) is selected with the resistor module unplugged. The hi-speed motor current return path to the S228 ground is external to the resistor module.
If it still runs in hi-speed position 4, leave it run and wiggle the motor connectors, fuses, tap the motor, wiggle all connectors including at the switch panel. You're not gonna damage the motor by the way.

If the motor still runs after all that, no need to measure the voltage at the motor connector. The motor itself and the relay are all good to go.

If the motor does not work in hi-speed anymore or is intermittent then i would:
-change the fuses with new ones 1st if not done already and also inspect the fuse socket contacts for corrosion, burnt or spread apart.

-wiggle all the above again including the switch panel.

-missing ground from the switches or connector from the resistor module terminals 1,2,and 3?
Put the fan speed in position 2, then with an ohm meter or continuity trouble light check to see if there's continuity from the resistor module pin 2 to ground. If no ground at pin 2, then the prime suspect would be the fan control switches or its connectors or an open wire somewhere.
If you look at Ken's schematic, there's multiple connectors and wiring from the resistor module to the control panel. Some might be hidden under the dash.

Not saying it is, but starting to look more and more like the problem is in the switch panel.

 

FYI, here's the back of the HVAC Climate Control Panel for a '99-'01 XJ.



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And the location of splice S228.



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Haynes and its brother by another mother, Chilton, are garbage.


Oh, and they are wrong a lot, too.

 

I agree, but its better than nothing!

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To the OPer, i forgot to mention when and if you check for ground continuity at resistor module pin 2, disconnect the battery or in the least keep the ignition off. Don't know how electrical savvy you are but thought i'd mention that just in case.
If you're brave enough, you could jury rig a couple jumpers with a 15A fuse in series with them and touch one end to resistor module terminal 2 and the other end to ground. If the blower runs at speed 2 that would confirm the problem is beyond the resistor module onto the switches and wiring/connectors.

If the resistor module is the correct replacement part and its connector ok then i'd strongly suspect one of the switches; the speed select switch or the one to the right of it or their connectors/wiring. Not uncommon for those switches to fail. Double check all ground terminations to the chassis.

 

is it though? There are many mistakes in those manuals that lead you in the wrong path...you end up worse off then before.

 

sometime i think there are as many mistakes on the forum from guys making up answers as there are mistakes in those books!!
lotsa guesswork here...!!

 

Yeah but a lot of people will trust their Haynes like their life's depended on it.....it's ridiculous. On the forum, if some bad advice given, there's people to shoot it down...when you are reading your Haynes there's no one but yourself

I also think it's hilarious when people come here for help, get great advice, and then say "oh well my Haynes or Chilton says to do it another way"....tf you come here for then if you trust your book so much haha

 

yeah,i was stuck with haynes bs till i found the forum. got great help here, fun to observe some posts.

 

WTF! I already agreed that Haynes manuals more or less suck lacking detail. JeeeZZ!

But i standby 'they're better than nothing' at least in my case.
Their generic electrical diagrams helped me trouble shoot problems and install electrical options by giving a general idea of whats going on.
Sometimes a general idea is all thats needed. Sometimes not.

Some installation examples i used Haynes electrical diagrams:
-to design and install my electrical fan off-delay after the engine is turned off (for heat soak).
-to install auxiliary driving lights with an (on-off-on) 3 position rocker switch.
Position 1, driving lights unconditionally on
Position 2 (off), driving lights unconditionally off
Position 3, driving lights on only when stock brights are on, off when brights are off

Just need to take their information with initial skepticism, a grain of salt and a good healthy dose of imagination.

 

cool man lol

 

Well I think I can wrap this post up atleast for now. A few days went by since I replaced the resistor and connector and still nothing worked. I've been busy so haven't done any more trouble shooting. Then after a few days passed, I needed my heat to clear up the frost on my window so I looked down at the climate control and said, the heat is going to work this time. I turned it on and bam, it came on. Sooo yeah, maybe it's jeep magic, probably more simple though. Hopefully my motor still has some more life in it or whatever it was that wasn't working hopefully keeps hanging on. Summer is around the corner! Thanks for all the help everyone. I will refer back to this if it stops working again.