Help Needed. P0480 Error...No Relays?

[marksuman1]

New here and needing help with my 2017 1500 Big Horn 3.6L.

Engine is overheating and I'm getting a P0480 error saying the Cooling Fan 1 Control Circuit is failing. Went to check fuses/relays but they're missing from the fuse box. Never had any issues before so I'm not sure if it came that way or if someone messed with my truck (see pics). Is there another relay closer to the radiator/fan that could have gone bad?

 

[Burla]

Is the cooling fan working? Probably an bizarre error when manu'd, maybe the lack of fuse finally fried the part, but how would it even get power? Put fuse back see if it resolves? Maybe you are right, somehow that fuse was taken or fell out somehow.

Had to look up how a relay works over how a fuse works, it appears like you can have a part working without a replay, the relay just prevents large amperage. So it could have been like that all along, and it finally fried the part. I would literally talk to dealer even out of warranty, maybe they can contact fca on your behalf. Why we ever went away from simple fuses escapes me. Something would go wrong, you go to store and spend a buck and it's fixed, go figure.

I don't really know, brain fog, but here is the link. Are our replays normally opened or normally closed, dunno.

 

[marksuman1]

Is the cooling fan working? Probably an bizarre error when manu'd, maybe the lack of fuse finally fried the part, but how would it even get power? Put fuse back see if it resolves? Maybe you are right, somehow that fuse was taken or fell out somehow.

Had to look up how a relay works over how a fuse works, it appears like you can have a part working without a replay, the relay just prevents large amperage. So it could have been like that all along, and it finally fried the part. I would literally talk to dealer even out of warranty, maybe they can contact fca on your behalf. Why we ever went away from simple fuses escapes me. Something would go wrong, you go to store and spend a buck and it's fixed, go figure.

I don't really know, brain fog, but here is the link. Are our replays normally opened or normally closed, dunno.

View attachment 464935

The cooling fan is not working. Talked to a local dealer and they weren't helpful at all. Couldn't tell me what relay was supposed to go in there without the old one, even though I explained not having one. Took it to a local mechanic as I need my truck back asap for work. Turns out it's the cooling fan assembly that needs replaced.

Appreciate the response!

 

[Nick_rp]

Just because Burla was giving you the 101 on relays i figured id jump in. A relay switchs by magnetism. Power goes in, energizes the magnet, the magnet than push/pulls the switching arm into place to either open or close the circuit. In burlas pic, the magnet would be the big red and black brick, and the arm its moving is the red bar.

The thing about relay failure is its usually because the magnet itself is failing and cant move the armature or the contact plate that the arm connects with is worn creating a poor circuit.

Anyway, without specific knowledge of your rig, sometimes the relay is on/near the fan itself and actaully acts like kind of a thermo switch. When it heats up enough, it switches the fan on and vice versa. I dont believe you have been running without a relay, its most likely in a different area

 

[indept]

Is the cooling fan working? Probably an bizarre error when manu'd, maybe the lack of fuse finally fried the part, but how would it even get power? Put fuse back see if it resolves? Maybe you are right, somehow that fuse was taken or fell out somehow.

Had to look up how a relay works over how a fuse works, it appears like you can have a part working without a replay, the relay just prevents large amperage. So it could have been like that all along, and it finally fried the part. I would literally talk to dealer even out of warranty, maybe they can contact fca on your behalf. Why we ever went away from simple fuses escapes me. Something would go wrong, you go to store and spend a buck and it's fixed, go figure.

I don't really know, brain fog, but here is the link. Are our replays normally opened or normally closed, dunno.

View attachment 464935

A relay does allow hi amperage, it just allows you to switch it on & off with low amperage control. In the case of the fan, if you didn't have relays they would have to run large wires from the ECU to the fan motor to supply high amps. The relay lets the ECU control it with low amp ( less than an amp) control. Same with starters, the starter solenoid is a relay. Without it they would have to run battery cable size wires to the ignition switch since they draw well over 100 amps.

 

[csuder99]

On my JK Wrangler the fan is not controlled by relays so I'd think the truck is likely a similar design. The fan has three wires, power, ground and a control wire that receives a PWM signal from the PCM. There is an electronic module in the fan housing that turns the PWM signal into varying fan speeds. Could be the control circuit wiring but more likely the electronics in the fan.

 

[Diabloeh]

New here and needing help with my 2017 1500 Big Horn 3.6L.

Engine is overheating and I'm getting a P0480 error saying the Cooling Fan 1 Control Circuit is failing. Went to check fuses/relays but they're missing from the fuse box. Never had any issues before so I'm not sure if it came that way or if someone messed with my truck (see pics). Is there another relay closer to the radiator/fan that could have gone bad?

View attachment 464912View attachment 464913View attachment 464914

Have you had any luck figuring out this issue? I’ve ran across the same issue with my 2013. Saw a different video stating it could be a relay on the bumper between the radiator and the grill.