[Mcwatt15]

I have a 2019 HC Challenger with some basic bolt on mods, running E85, ID1300 injectors, 2.65 upper, 10% lower, boost a pump, headers and full exhaust and 180 t-stat. A couple months ago the car overheated while driving slow. I'm talking 240 degrees before I shut it down. I noticed the AC quit too.

I put a new mishimoto t-stat in and still warmed up and AC quit. So I diagnosed as a bad engine fan. I splurged $1200 for a new fan and still nothing! Was told it may be a bad battery so I also replaced that. I'm at a loss as to what direction to even go now. The car goes in for more dyno tuning soon but if I can't keep it cool that will be impossible. Any help is greatly appreciated!

 

[SickToo]

Welcome

 

[Mcwatt15]

Welcome

Thank you!

 

[MrFixitND]

I have a 2019 HC Challenger with some basic bolt on mods, running E85, ID1300 injectors, 2.65 upper, 10% lower, boost a pump, headers and full exhaust and 180 t-stat. A couple months ago the car overheated while driving slow. I'm talking 240 degrees before I shut it down. I noticed the AC quit too.

I put a new mishimoto t-stat in and still warmed up and AC quit. So I diagnosed as a bad engine fan. I splurged $1200 for a new fan and still nothing! Was told it may be a bad battery so I also replaced that. I'm at a loss as to what direction to even go now. The car goes in for more dyno tuning soon but if I can't keep it cool that will be impossible. Any help is greatly appreciated!

Welcome to the forum!

First thing I would check is the fuse(s) and relay(s) for the fan. Check your battery box, should be the maxi fuses #8 and #24, 50A according to the manual. Pretty sure the relay(s) are in the underhood box too. Check to be sure you have battery voltage to the relay, and that your wiring is good from the relay to the fan motor connector too.

Hope you get it sorted!

 

[ScLeCo]

$1,200 for a fan? I need to know more about this apparently gold plated cooling fan.

 

[Mcwatt15]

Welcome to the forum!

First thing I would check is the fuse(s) and relay(s) for the fan. Check your battery box, should be the maxi fuses #8 and #24, 50A according to the manual. Pretty sure the relay(s) are in the underhood box too. Check to be sure you have battery voltage to the relay, and that your wiring is good from the relay to the fan motor connector too.

Hope you get it sorted!

Checked all that and it's all good. With the car running I have power on the big positive wire but the fan doesn't turn on at all.

 

[Mcwatt15]

$1,200 for a fan? I need to know more about this apparently gold plated cooling fan.

Yep a little over $1200 plus tax at the local dodge dealer.

 

[MrFixitND]

Checked all that and it's all good. With the car running I have power on the big positive wire but the fan doesn't turn on at all.

So I dont have a wiring diagram for a '19, but how these usually work is the power comes from the battery, through the fuse in the fuse box, to the relay in the fusebox, then straight to the motor, and back through the ground wire to either a frame ground or straight to the battery. The ECM/PCM controls the system by turning on and off the relay. If you are getting battery voltage to the motor wiring connector, then I would search for a bad ground. Check all of the frame and engine ground points. It is also possible to show voltage at the connector with it unplugged, but still have a poor connection (relay most likely) that doesnt get enough power through when there is a load on it.

I have a FSM for a '15, I can look up the wiring diagram if you would like. I would guess that system is going to be pretty much the same on a '19

 

[Mcwatt15]

So I dont have a wiring diagram for a '19, but how these usually work is the power comes from the battery, through the fuse in the fuse box, to the relay in the fusebox, then straight to the motor, and back through the ground wire to either a frame ground or straight to the battery. The ECM/PCM controls the system by turning on and off the relay. If you are getting battery voltage to the motor wiring connector, then I would search for a bad ground. Check all of the frame and engine ground points. It is also possible to show voltage at the connector with it unplugged, but still have a poor connection (relay most likely) that doesnt get enough power through when there is a load on it.

I have a FSM for a '15, I can look up the wiring diagram if you would like. I would guess that system is going to be pretty much the same on a '19

I will search for a bad ground. I can't find any relays in the front or back labeled engine fan. Thank you for these tips!

Yes if you have that wiring diagram I'd appreciate it!

 

[Mcwatt15]

I should also note it has the Tazer double bypass in the trunk. Been debating ordering the Tazer but adding MORE electronics is not something I prefer to do.

 

[MrFixitND]

If there isn't a relay, it is also possible that it grounds through the PCM internally. (PWM speed control?) I'll have to find my manual and see what I can come up with.

Hmm... I know you can turn the fans on from the TAZER, I wouldnt think you would be able to disable them? Might want to look at the TAZER documentation.

 

[Mcwatt15]

If there isn't a relay, it is also possible that it grounds through the PCM internally. (PWM speed control?) I'll have to find my manual and see what I can come up with.

Hmm... I know you can turn the fans on from the TAZER, I wouldnt think you would be able to disable them? Might want to look at the TAZER documentation.

I don't have the Tazer, previous owner had that installed. Fan was working wonderfully til this fall. Could I somehow make a ground for it? The fan harness is not that far from the jump ground point under the hood.

 

[cobrakid]

check your underhood fuse/relay box.... the LID should identify locations of fan stuff.
my 2021 was confusing online as to where to look, and the box itself had the correct spots, fuses, and relays.

good luck, as I hate electrical gremlins too.

 

[Mcwatt15]

check your underhood fuse/relay box.... the LID should identify locations of fan stuff.
my 2021 was confusing online as to where to look, and the box itself had the correct spots, fuses, and relays.

good luck, as I hate electrical gremlins too.

I have looked and looked, nothing labeled fan. There is a maxi fuse but it's good and has power.

 

[cobrakid]

I have looked and looked, nothing labeled fan. There is a maxi fuse but it's good and has power.

...I should have clarified..... the labeling is in the UNDER SIDE of the box lid. did you turn it upside down & check there?

 

[Mcwatt15]

...I should have clarified..... the labeling is in the UNDER SIDE of the box lid. did you turn it upside down & check there?

Lol ya I knew what you meant.

 

[xcesiv]

 

[Mcwatt15]

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Awesome info. Which relays are they though? Like stated, nothing on the fuse box covers is labeled fan.

 

[xcesiv]

 

[xcesiv]

I’d say 7, 8 & 24