2003 Liberty Renegade radiator fan won’t turn on, all my diagnostic knowledge exhausted

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chloecarter

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I bought a 2003 Liberty Renegade a couple months ago and it had a bunch of issues, most of which I’ve fixed but this one has stumped me. The previous owner had the radiator fan hooked up to a switch in the cabin directly from the battery, which worked fine but I had to figure out what went wrong in the first place. I replaced the radiator and cooling fan for unrelated reasons (new fan works with direct power from batt, that’s not the issue). I then found that the radiator fan relay was missing, so I bought a new one (80 united states dollars!) and plugged it in, still no dice with the rad fan BUT the code for the missing relay DID go away. I then decided to toss a new coolant temp sensor in despite the fact that the temp gauge on the cluster was functioning fine, that didn’t fix it. After that, I had my friend who knows more about electrical stuff than me come test continuity with a multimeter, I don’t personally remember exactly what she tested, but it was a bunch of different points in the wiring, she says the wires are good. We also found that voltage was being passed to the fan, but it was very low, 0.1-0.5v. At this point we were really frustrated so we decided to wire the fan to a switched fuse in the fuse box, only to find out that none of the fuses are switched??? Why does the fuse box receive power 24/7?? We are mostly familiar with Hondas, so this was alien to us. Anyway, both my friend and I are completely stumped, does anyone have any ideas before I spend $200++ on a professional diagnosis?

POSSIBLY RELATED ISSUES
When the headlights are on, the wipers move incredibly slowly, maybe 1/5 of their normal speed. The left turn signal, not the right, clicks twice as fast as usual as if a bulb is blown, but it’s not. This all rectifies when you turn off the headlights. After the headlights have been on, if you turn off the car you can see from the outside that the radio flashes on for 1s, off for 1s, and repeats until the headlights automatically turn off. When trying to lock it after the lights have been on, the doors lock but the car struggles to honk the horn as it usually does when locking the car. If you rapidly press the button, it’ll slowly get louder and louder until it finally squeaks out a full beep after about 30s. I know all this stuff is weird, and it’s not SUPER important BUT I figure since it’s electrical there’s a small chance that the same thing is causing these issues. Thank you in advance for your help!
 

JeepJeepster

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Without testing things, the headlights/wipers sound like a bad ground or connection. You would need a wiring diagram and just start checking to see where the voltage is low/normal.

Does the 03 KJ use a fan module thats under the battery?
 

chloecarter

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Without testing things, the headlights/wipers sound like a bad ground or connection. You would need a wiring diagram and just start checking to see where the voltage is low/normal.

Does the 03 KJ use a fan module thats under the battery?
By fan module do you mean the fan relay? it’s generally under the battery/fuse box bolted to the frame yeah
 

JeepJeepster

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By fan module do you mean the fan relay? it’s generally under the battery/fuse box bolted to the frame yeah

Pretty sure thats called a fan module and it only came on the 02-03 Libertys (I think). It doesnt have any sort of mechanical relay in it.

The 04 and up Libertys got fan relays in the PDC.


I know nothing about it, but I've got to wonder if its pulse width modulated by the PCM.
 

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