Alternator on 2014 Jeep Grand Cherokee

Submitted: Sunday, Mar 15, 2015 at 19:08
ThreadID: 117079 Views:7131 Replies:5 FollowUps:9
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Hi All,

I have company car that is a Jeep Grand Cherokee and hope to install Anderson plugs on it to charge battery and trickle charge a 3-way fridge in camper trailer.

Does anybody know if this vehicle has a "smart" alternator and if this function can be turned off by a dealer? I have been told that a Ford Ranger has this ability to deselect the "smart " Alternator option.

Cheers Ben
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Reply By: HKB Electronics - Monday, Mar 16, 2015 at 10:55

Monday, Mar 16, 2015 at 10:55
The only mention I have found regarding the Jeep is on Redarc's site that shows 2014 on use a variable voltage alternator, therefore earlier models must use a standard alternator. Note though the Redarc listing has some errors in it.

A simple test will confirm what you have, after car has been garaged overnight, start engine and with the engine at around 1500RPM measure the voltage across the cranking battery terminals and note. Take car for a 30 minute drive and retest.

If charging voltage is more or less the same your vehicle is fitted with a standard alternator. If first reading was around the 14.4V mark with ambient around 25C and second reading was around 13.5V-13.8V you probably have a high temperature compensation alternator fitted. If second reading was below 13.5V ie 12.7V or similar you most likely have an ECU controlled setup.

I have not heard anything about the Jeeps smart charge system if it has one being able to be turned off, I suggest your refer to one of the American Jeep forums for more info.

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AnswerID: 550054

Follow Up By: Ben M10 - Tuesday, Mar 17, 2015 at 06:58

Tuesday, Mar 17, 2015 at 06:58
Thanks HKB, I will give it a go. I have since spoken to the Jeep service centre and they believe the alternator is a "smart" unit.
FollowupID: 836525

Follow Up By: Jarse - Wednesday, Mar 18, 2015 at 10:07

Wednesday, Mar 18, 2015 at 10:07
Ben, yes it does have a 'smart' alternator.

My GC's voltmeter is mainly around 13v. I suspect it rounds up. I can confirm this because the CTEK in the Vista only charges sometimes, whereas on my previous 05 Prado (smarter alternator, IMO) :D used to run the CTEK continuously.

I've done a workaround where I run the Anderson to the solar input of the CTEK. Not very efficient considering the original setup would put muck more into the batteries of the Vista than 20A...

Leigh, I wonder if there is a similar solution to the problem as you addressed for other vehicles? (ie fuse/diode combination).
FollowupID: 836596

Follow Up By: Member - Rodney J2 - Thursday, Mar 19, 2015 at 07:38

Thursday, Mar 19, 2015 at 07:38
Hi Jarse,
My 2014 GC Overland was putting out 13.1v by the Voltmeter which was about cut in point for the battery switch which sent power to refrigerator, sometimes it would and sometimes it wouldn't. About 6weeks ago we sent GC in on a Recall for an Electrical problem in the steering column and they also did another couple of Comp Updates at the same time.
On our way home I switched to Voltmeter display and we were making 14.2v and have done so ever since, now the System all works beautifully.
I rang back the Service Dept and asked if anything they had done to rectify this and the did not know except to say it may have been something in one of the Updates ????
Maybe your GC needs Service Updates and Voltage will increase ???

FollowupID: 836655

Reply By: get outmore - Monday, Mar 16, 2015 at 22:55

Monday, Mar 16, 2015 at 22:55
How exactly does one trickle charge a 3 way fridge??
AnswerID: 550082

Follow Up By: Ben M10 - Tuesday, Mar 17, 2015 at 07:22

Tuesday, Mar 17, 2015 at 07:22
My fridge is a Thetford 93 lt.

When battery is selected on the fridge, the fridge operates at a reduced power and draws around 14 amps at 14V.

The manual states;

"DC operation is intended only to maintain the temperature of the refrigerator and its contents when they are already cool."
FollowupID: 836527

Follow Up By: Gronk - Tuesday, Mar 17, 2015 at 13:04

Tuesday, Mar 17, 2015 at 13:04
when you select battery, I'd suspect it just uses battery power.....if it was at reduced power, it wouldn't be drawing 14 amps..

The manual would be correct, but if you had big enough cables and you can keep a good voltage up to it , it should work as per gas settings, but why would you ??
FollowupID: 836541

Follow Up By: Ben M10 - Tuesday, Mar 17, 2015 at 15:12

Tuesday, Mar 17, 2015 at 15:12
Thanks for that Gronk. I am simply trying to find the best way of keeping the fridge cool whilst driving using 12v.
FollowupID: 836548

Reply By: michael k7 - Tuesday, Mar 17, 2015 at 13:32

Tuesday, Mar 17, 2015 at 13:32
Yes I have the latest Grand jeep Cherokee and have had this problem also and have had to change the Redarc device on the car to fool the alternator to putting out the max, and I believe a DC charger in the van all works great now.

They say the easiest way is to drive with your headlights on making the alternator put out the maximum but I preferred to fix it right

Cannot help you as to weather it has a function to turn it off.
The auto electrician I used said most new cars now have this sort of alternator so beware if buying a new car to tow your existing setup as your batteries may not charge.
AnswerID: 551107

Follow Up By: Ben M10 - Tuesday, Mar 17, 2015 at 15:15

Tuesday, Mar 17, 2015 at 15:15
Thanks Michael,

Could you advise the redarc device that you used and if you put a DC charger in your van?
FollowupID: 836549

Follow Up By: michael k7 - Wednesday, Mar 18, 2015 at 01:11

Wednesday, Mar 18, 2015 at 01:11
Redarc BCDC1220. 12v 20a DC/DC 3stage battery charger like the person with the Range Rover my car battery is the only one this Redarc charges both 120A batteries in the van through the Anderson plug on the gauge I seem him use it charges now at just over 14volts
FollowupID: 836587

Follow Up By: michael k7 - Wednesday, Mar 18, 2015 at 01:15

Wednesday, Mar 18, 2015 at 01:15
Sorry about that I did not read the Range Rover message correctly late here so ignore the similarities
My car is a Grand Cherokee Blackhawk
FollowupID: 836588

Reply By: garrycol - Tuesday, Mar 17, 2015 at 22:10

Tuesday, Mar 17, 2015 at 22:10
I cannot speak to a Jeep but I do have a Range Rover Sport that does have a smart alternator.

I do not have a secondary battery in the car and have connected an andersen plug in the rear connected directly to the main car battery. My camper has a 110ah battery that runs every thing in the camper including the 3 way when 12v is selected. The camper is plugged into the car andersen plug so when driving the alternator is charging the car battery and the camper battery.

I have had no issues when driving with the camper connected and the 3 way on 12v - fridge worked fine, the camper battery charged and the car systems working fine. The system is smart enough to consider the combined load and adjust accordingly.

AnswerID: 551140

Reply By: patrolman2 - Saturday, Mar 21, 2015 at 17:22

Saturday, Mar 21, 2015 at 17:22
Hi Ben,I would suggest you have a smart alternator in the JC.and would recommend you look on the Redarc site.They have solutions to solve your problem.Piranah also have out a chip to insert into the charging circuit which "confuses"the ECU into producing an extra 0.5volt or so,(which can be significant). From memory it is in the vicinity of $100.You could keep this in mind as an option. Cheers
AnswerID: 551347

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