Replacing Alternator Advice

teajayde

Member
First Name
Trevor
Joined
Jul 23, 2021
Messages
6
Reaction score
3
Location
Santa Cruz, CA
Vehicle(s)
Wrangler JLU Sport S
Hello,

just bought my first wrangler this year in January. It’s a 2018 JLU Sport S with 41,000 miles.
Just last week after stoping at a store when I went to leave my Jeep wouldn’t start. I had power but no turn over. I used my portable jumper and that didn’t work. A friendly stranger then used their Tacoma to give me a jump. Still nothing. I called a tow and while waiting for them I tried jumping a 3rd time. This time it worked but my wrangler was shaking and sounded like it was going to die. In addition my display was saying “stop safely. Vehicle will shut off soon” dash display we’re going crazy. Blinking/flashing. Wipers came on. After shutting the Jeep off I no longer had any power.

I had my wrangler towed to my local dealership and had it diagnosed. First the dealership said it was the aux battery and fuser relay. Then they said the main fuse was blown and that someone jumped the car reversed. I know for a fact I didn’t do this in my 3 attempts to jump. Said it would be $225 to replace the battery and fuse. Not a big deal.
Well now 10 days later they are telling me the wrangler now needs a new alternator. That they replaced the battery and fuser replay but now the alternator starts smoking when they start the car. They said replacing the alternator will be $1,500. $500 parts, 2 hours labor at $225 an hour plus the cost of battery and fuse replacement.

the dealership also said if changing the alternator doesn’t work that they will have to replace the PCM which would be very costly.

so I have two questions:

should I save the money and change the alternator myself? I’ve been trying to find YouTube videos showing how to do it and can only find videos changing the alternator on the JK. Does anyone have a JL alternator replacement video they know of?

my other question is: does this diagnosis sound correct to this community? How could a 3 year old vehicle already need a new alternator?

thanks in advance for any help anyone can provide. This is my first Jeep and my first forum post so please forgive any informalities.
Advertisement

 

garyji

Well-Known Member
First Name
Gary
Joined
Dec 2, 2017
Messages
279
Reaction score
381
Location
Western NC
Vehicle(s)
2017 JK Sahara, 2021 JLU Willys
Can't help, but welcome. I'm sure someone will have some good advice.

G.
 

coupedncal

Active Member
First Name
CoupednCal
Joined
Aug 3, 2019
Messages
28
Reaction score
22
Location
SF Bay Area
Vehicle(s)
Looking at Jeeps
I am confused. Why aren't they covering this repair under warranty?
 

Maverick909

Well-Known Member
First Name
Brian
Joined
Jan 15, 2019
Messages
1,892
Reaction score
2,145
Location
SoCal
Vehicle(s)
2018 JLU Sporticon, 1976 GMC K15 Lifted on 35's
this is interesting. typically they say both batteries should be replaced at the same time.. As for the alternator you never know when you get a botched part. alternators are rather simple to change out 30 mins max. once you have done one they're all the same. 1 recommendation is if you don't have the tow package you have the smaller 180A alt. i would upgrade to the 240amp alt. if your going to change it. This is a good idea if you plan to have lighting, a winch, etc.. now is someone happen to mess up and reverse the polarity when jumping, it could damage the PCM. DC voltage is polarity sensitive and devices of dc voltage reallllly dis-like reverse polarity.. Another possibility is maybe the voltage regulator failed and you over voltage the system. a lot of possibilities with these new smart cars. best of luck to you. let us know what happens in the end
 

Maverick909

Well-Known Member
First Name
Brian
Joined
Jan 15, 2019
Messages
1,892
Reaction score
2,145
Location
SoCal
Vehicle(s)
2018 JLU Sporticon, 1976 GMC K15 Lifted on 35's
I am confused. Why aren't they covering this repair under warranty?
36K mile warranty typically. for all things and the powertrain is 5year and it was used.
 

eck

Well-Known Member
First Name
John
Joined
Dec 3, 2018
Messages
368
Reaction score
543
Location
Apex NC
Vehicle(s)
2018 JLU MOAB HellaYella
I am assuming you have the 3.6L since it's (1) a 2018 and (2) has the aux battery. The alternator on the 3.6L is extremely easy to replace. It's right at the very top front. I don't think you could find an easier vehicle to change an alternator on.
 

Heimkehr

Well-Known Member
First Name
James
Joined
Sep 3, 2020
Messages
2,030
Reaction score
3,662
Location
Pennsylvania
Vehicle(s)
2021 Jeep Wrangler Unencumbered
...they are telling me the wrangler now needs a new alternator. That they replaced the battery and fuser replay but now the alternator starts smoking when they start the car. They said replacing the alternator will be $1,500. $500 parts, 2 hours labor at $225 an hour...
I've replaced several alternators. Being quoted $225/hr. for labor would chase me into DIY territory pretty quickly.
 
OP
OP

teajayde

Member
First Name
Trevor
Joined
Jul 23, 2021
Messages
6
Reaction score
3
Location
Santa Cruz, CA
Vehicle(s)
Wrangler JLU Sport S
this is interesting. typically they say both batteries should be replaced at the same time.. As for the alternator you never know when you get a botched part. alternators are rather simple to change out 30 mins max. once you have done one they're all the same. 1 recommendation is if you don't have the tow package you have the smaller 180A alt. i would upgrade to the 240amp alt. if your going to change it. This is a good idea if you plan to have lighting, a winch, etc.. now is someone happen to mess up and reverse the polarity when jumping, it could damage the PCM. DC voltage is polarity sensitive and devices of dc voltage reallllly dis-like reverse polarity.. Another possibility is maybe the voltage regulator failed and you over voltage the system. a lot of possibilities with these new smart cars. best of luck to you. let us know what happens in the end
Thanks for the reply. I’m going to replace the alternator myself and upgrade the Amps. I’ll keep my fingers crossed that it’s not the PCM. Thanks again.
 

OP
OP

teajayde

Member
First Name
Trevor
Joined
Jul 23, 2021
Messages
6
Reaction score
3
Location
Santa Cruz, CA
Vehicle(s)
Wrangler JLU Sport S
I've replaced several alternators. Being quoted $225/hr. for labor would chase me into DIY territory pretty quickly.
Exactly! That’s what made me seek out this forum. 2 hours at for $450?!. I’d rather take 8 hours and learn how to to do it myself for that much money.
I appreciate the advice, thank you!
 
OP
OP

teajayde

Member
First Name
Trevor
Joined
Jul 23, 2021
Messages
6
Reaction score
3
Location
Santa Cruz, CA
Vehicle(s)
Wrangler JLU Sport S
I am assuming you have the 3.6L since it's (1) a 2018 and (2) has the aux battery. The alternator on the 3.6L is extremely easy to replace. It's right at the very top front. I don't think you could find an easier vehicle to change an alternator on.
Your assumption is spot on. Thank you so much for the advice. I’m going to give it a go myself. I’m a little worried about not having the right tools and the sepertin belt but it’s worth a shot!
 

dpike

Well-Known Member
Joined
May 28, 2020
Messages
321
Reaction score
364
Location
New Jersey
Vehicle(s)
'20 JLUR
i'm not sure i'd so blindly replace the alternator based on what the dealer said. dealers tend to throw parts at things until they replace the right one without a care what it will cost you.
 
OP
OP

teajayde

Member
First Name
Trevor
Joined
Jul 23, 2021
Messages
6
Reaction score
3
Location
Santa Cruz, CA
Vehicle(s)
Wrangler JLU Sport S
i'm not sure i'd so blindly replace the alternator based on what the dealer said. dealers tend to throw parts at things until they replace the right one without a care what it will cost you.
Good point. I’ll try and replace both batteries myself first. If that doesn’t worry I’ll change the fuse relay. And if that still doesn’t work I’ll give the alternator a go. Appreciate the advice!
 

oldcjguy

Well-Known Member
First Name
Jim
Joined
Aug 26, 2020
Messages
318
Reaction score
362
Location
Central FL
Vehicle(s)
16 Challenger Hellcat, 19 Challenger Scatpack, 20 JLUR Recon
Occupation
Software Engineer
Powertrain warranty should be 5yr/60k

Either way, alternator is one of the more simple swaps on the engine. Plenty of vids on replacing a serpentine belt. Take pictures if the setup and wires with your phone before you start. Make sure it looks the same when you're done.
 

Maverick909

Well-Known Member
First Name
Brian
Joined
Jan 15, 2019
Messages
1,892
Reaction score
2,145
Location
SoCal
Vehicle(s)
2018 JLU Sporticon, 1976 GMC K15 Lifted on 35's
Thanks for the reply. I’m going to replace the alternator myself and upgrade the Amps. I’ll keep my fingers crossed that it’s not the PCM. Thanks again.
No problem
 
Advertisement

PSC Motorsports
 
Advertisement
Top