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Absolutely no power even with jumper cables attached

1K views 15 replies 5 participants last post by  Kruzin 
#1 ·
Hi all, for some reason my 2017 Jeep Grand Cherokee Altitude will not give me any power at all, even with jumper cables attached. Absolutely no power, even though the jumper cables register 13 volts on the Jeep end, and 14 volts on the Honda end (How is that even possible I don't know). Cables attached under hood to posts and directly to the battery, makes no difference. terminals cleaned and re-attached, no difference.

I'm completely out of ideas. I've removed and cleaned battery terminals. I just have zero power even though 13 volts are charging the battery.

It jumpstarted one single time, but as soon as I removed the cables it shut off and has never received power again.
 
#2 ·
Jump starting modern cars is touchy at best. One wrong move and you can quickly fry your TIPM (computer), which will leave the vehicle completely dead.
Did you follow the procedure in your owner's manual to the letter? There is a specific order to connect and disconnect the cables to help avoid electrical damage.
Jump to page 434 of 643 to see that section of the manual: http://www.fcacanada.ca/owners/en/manuals/2017/2017E-Grand_Cherokee-OM-5th_R1.pdf
 
#3 ·
Jump starting modern cars is touchy at best. One wrong move and you can quickly fry your TIPM (computer), which will leave the vehicle completely dead.
Did you follow the procedure in your owner's manual to the letter? There is a specific order to connect and disconnect the cables to help avoid electrical damage.
Jump to page 434 of 643 to see that section of the manual:
Mmmm, so I might have fried the TIPM? Hmm, alright, worth a check. I attached them correctly, but who knows.
 
#4 ·
Update: Solved

The dealership sold me a battery on it's last legs. I hooked up a brand new batter chumpty style with wire coming off the terminals to the new battery and it still didn't work so I ruled out the battery prematurely. Fully installling a brand new battery properly solved the issue.

Thank you everyone.
 
#6 ·
My question is why didn't the jump cables provide power regaurdless of the battery issue?

I'm curious, becasue i have a dead jeep on the operating room table as we speak.
 
#7 ·
@Rivka
Is this still the same problem as outlined in this thread? https://www.jeepforum.com/forum/f19/won-t-start-take-jump-silent-but-accessory-power-works-3640346/

If yes, check to see if you're getting power to fuses 9, 10, 11, and 12 in the fuse block when the ignition is switched on. If no power is present at those fuses with the ignition on, disconnect the plug from the ignition switch and see if you're getting battery power at the red wire in pin 1. If no power is present, check to see if PDC fuse #22 is blown -- if power is present at the red wire however, check to see if you have continuity through the ignition switch in the on/run position from pin 1 to pin 2.
 
#8 ·
yes and no.
life does what life does and I spent a few years away from the jeep. never got to sort out the older issue, assumed it was starter and i would fix it later when i came back. jeep went into storage and I dealt with elderly family for a while.

anyway got back to this side of the world and went to get the starter replaced and no good, they then thought it was the ignition switch, it wasn't. and they are telling me that there is ZERO power to the dash and they can't read the computer. So now I'm guessing the computer is bad, but when I stumbled on this thread doing my searching the forum, I thought I would check-in and see if I can get some insight. They say they don't have any idea what to look at next, which seems odd.
the place that is looking at it is a highly regarded independent jeep shop, though honestly, I don't like how they drag their feet and do things, so I'm considering getting the jeep to the good independent shop that takes care of my non-jeep car. would love to have a direction to point them off towards.
 
#9 ·
ill hope back over to my old thread and sort out my jeep, just checking if I could glean some info, just noticed that the OP only ever had these 3 posts, so he is possibly already gone.
 
#11 ·
thanks, ill dig into that. here was what the shop report was.

"vehicle has no communication w/ecu, no egine light/gauges, will not turn over or start with a jumper switch. found burnt out alternator to battery fuse link and corroded previous repair from battery to PDC. diag time has been spent to verify power, relays, ignition switch actuator pin, and ignition switch which was replaced due to corrosion. further diagnostics will be required."​
 
#12 ·
Sounds like you've got a bit of a project ahead of you, with all the notes about corrosion and whatnot.

See attached for the schematic from PDC fuse 22 through the ignition switch to the fuse block. The instrument cluster must get power from fuse 10 in order to switch on, likewise the PCM requires power from fuse 12 to switch on. Without power getting to the PCM from the ignition switch, it'll never power up to talk to a scanner.
 

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#13 ·
damn, see this is why I always loved this forum, it's amazing how much more intelligent the replies can be around here than the rest of the dumbed-down internet.
wish me luck
 
#14 ·
If you find there's no power getting to the red wire at pin 1 of the ignition switch plug and also that PDC fuse 22 is good, you can unplug the two halves of connector C301 in the driver's foot well to check for power at the red wire in pin B7.
Parallel Font Auto part Engineering Line art


Rectangle Parallel Pattern Font Diagram

Hopefully we can assume the new ignition switch is good since it was replaced, but if we have power getting to the switch but not to fuses 9-12 in the fuse block, it'd be a good idea to go ahead and do a continuity check from pin 1 to 2 with it turned on anyway. The next step if the ignition switch checks out will be to check the PK/LG wire running from the ignition switch to the fuse block.

Oh, and good luck. :thumbsup:
 
#15 ·
@Rivka

I never got an answer for why the Jeep wouldn't start even with jumper cables attached. I just have no idea. And even running wires from the battery to a new battery outside the vehicle in parallel didn't work (How that is possible I have no idea, maybe a dead battery fault detection sensor or something!?).

But when I just bought a brand new battery and fully installed it (I figured if it didn't fix the problem I'd have a new battery waiting in the wings for when I did need a new battery), the Jeep acted like nothing was ever wrong. Started up fine and gave me a look like, "What?"
 
#16 ·
Jumper cables are very inefficient for transferring power because of the clamps. The pointy jaws of those clamps only really make contact with a couple very small surfaces of the cable ends, while an actual battery cable end contacts the entire pole of the battery. This is why if the battery in a vehicle is dead, you will usually have to leave the jumper cables hooked up to a running vehicle for several minutes to get a little bit of juice back into the dead battery to get it going before it will even try to turn over. With the limited contact surface of jumper cable clamps, it's like only connecting the batteries together with a 12 gauge wire
 
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