[Bedz101]

Hi all,

Hopefully someone here can help. 2015 Challenger Hellcat and suddenly the HVAC blower stopped working. From initial testing It appears there is no voltage going to resistor. While I'm not an electrical engineer is it safe to assume that one of the three leads going into the actual resistor should be 12 volts? I understand the voltage/amps coming out of the resistor shouldn't be as the resistor reduces and thereby controls the fan speed.

I'm lost at this point. What should I check next? Any suggestions would be greatly appreciated.

Thanks in advane,

Mike

 

[Blickie]

Hi all,

Hopefully someone here can help. 2015 Challenger Hellcat and suddenly the HVAC blower stopped working. From initial testing It appears there is no voltage going to resistor. While I'm not an electrical engineer is it safe to assume that one of the three leads going into the actual resistor should be 12 volts? I understand the voltage/amps coming out of the resistor shouldn't be as the resistor reduces and thereby controls the fan speed.

I'm lost at this point. What should I check next? Any suggestions would be greatly appreciated.

Thanks in advane,

Mike

Mike, step 1 is check the fuses that serve the systems not working. Your post didn't mention fuses.

Let us know....

 

[Bedz101]

Yep, I failed to mention it but the first thing I did was to check all the fuses and they were all fine.

 

[Blickie]

Yep, I failed to mention it but the first thing I did was to check all the fuses and they were all fine.

OK, next might be the relays for the affected circuits. Might try unplugging, inspecting all male & female pins & reinstalling.

 

[Bedz101]

I just checked position #71, fan relay, in the rear fuse block and it appears fine.

Any other suggestions would be greatly appreciated. Thanks for the replies so far.

 

[Blickie]

I just checked position #71, fan relay, in the rear fuse block and it appears fine.

Any other suggestions would be greatly appreciated. Thanks for the replies so far.

When you say you checked fuses, you pulled them out and checked them with an Ohm Meter?

Well, a relay can look fine externally and not function. Might be time to get the dealer involved. They would know most likely fault(s) and be able to get you going again.

Let us know...

Best!

 

[Bedz101]

I didn't have an ohmmeter; however I swapped the 5 pole rear defrost relay, which is fine as the defroster is functioning, with the 5 pole fan relay and still the same issue unfortunately.

The car is out of warranty and I would prefer not to take it to a dealership.

Any other suggestions would be appreciated.

Thanks again,

Mike

 

[Blickie]

I didn't have an ohmmeter; however I swapped the 5 pole rear defrost relay, which is fine as the defroster is functioning, with the 5 pole fan relay and still the same issue unfortunately.

The car is out of warranty and I would prefer not to take it to a dealership.

Any other suggestions would be appreciated.

Thanks again,

Mike

Well, we've tried the proper/easy stuff but beyond that...

Think of about this. Talk to your Dealer Finance person and ask them what an Extended Warranty would cost. Tell them you have a problem now and you'll purchase the warranty if they cover your current issue.

 

[Bedz101]

Just a quick update....it turns out there is a junction block above the blower / resistor on the firewall that powers the resistor and the connection was loose. Pushed it back in tight and I'm all good.

Thank you for your replies,

Mike

 

[Blickie]

Just a quick update....it turns out there is a junction block above the blower / resistor on the firewall that powers the resistor and the connection was loose. Pushed it back in tight and I'm all good.

Thank you for your replies,

Mike

Good news, thx

 

[Himmelkat]

I just checked position #71, fan relay, in the rear fuse block and it appears fine.

Any other suggestions would be greatly appreciated. Thanks for the replies so far.

Take another identical relay and put it in the same spot. Quite a few of them on the Challenger are the same exact part.
Also, check for continuity between ground and the downstream side of the relay. Ultra-low resistance, as in a short circuit, is a bad sign, that a wire is violated somehow. There should be some normal DC motor-style resistance between the hot output from alternator and the ground.

 

[Lfaboulos34]

Wires? Connection issue?