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Chris
Chris, Shop Foreman
Category: Jeep
Satisfied Customers: 13874
Experience:  Jeep Certified Master Tech
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Second opinion] 180ma draw on fuse 7, yes ase tech 25

Customer Question

Second opinion] 180ma draw on fuse 7
JA: Have you checked the vehicle's manual yet?
Customer: yes ase tech 25 years....this is a bugger
JA: What is the model/year of your Jeep?
Customer: 98 jeep grand cherokee laraedo 4.0l
JA: Are you fixing your Grand Cherokee yourself? What have you tried so far?
Customer: everything lol
JA: Anything else you want the mechanic to know before I connect you?
Customer: tailgate switches are all unplugged and new alternator....150a just for giggles.... it's my truck
Submitted: 2 months ago.
Category: Jeep
Expert:  Chris replied 2 months ago.

Hello, my name is ***** ***** I will do my best to assist you today. Give me a minute to pull up the diagram and see what circuits fuse 7 powers up. This is fuse 7 in the PDC under the hood, or the fuse box in the cab?

Chris

Customer: replied 2 months ago.
Mux tow under hood fuse #7 inside 160 ma drain
Expert:  Chris replied 2 months ago.

Okay thanks. Be right back

Customer: replied 2 months ago.
I have disconnected everything on the tailgate. Also the OEM amp headlight sensor
Customer: replied 2 months ago.
the cluster
Expert:  Chris replied 2 months ago.

Ok, fuse # 7 inside supplies power to the BCM, instrument cluster, audio amp (if equipped), and auto headlamp sensor (if equipped). Click on the link below to see the diagram. Try disconnecting the BCM and cluster next. I have seen the BCM cause this. BTW.

Chris

Customer: replied 2 months ago.
I have 3 bc 'needed' same draw on all 3
Customer: replied 2 months ago.
Bcms
Customer: replied 2 months ago.
I have a fsm and diagrams
Expert:  Chris replied 2 months ago.

Sorry, did you say that you have tried 3 BCm's?

Customer: replied 2 months ago.
I have 3 same draw on all
Expert:  Chris replied 2 months ago.

If you disconnect the BCM does the draw go away? Something may be keeping the BCM "awake"

Customer: replied 2 months ago.
I was thinking the same way. Disconnected the bcm no draw but what is keeping it awake
Expert:  Chris replied 2 months ago.

Let me think about this.

Chris

Expert:  Chris replied 2 months ago.

I wonder if one of the door key cylinder switches is stuck. They are all hard wired to the BCM. Do you have scan tool that will display BCM inputs and outputs?

Chris

Customer: replied 2 months ago.
No. If I did I wouldn't be bothering you
Customer: replied 2 months ago.
Btw the only scan tool that would read this would be a dealer drb 3
Expert:  Chris replied 2 months ago.

Gotcha. Well on that vehicle, only hard wired inputs should "wake up" the BCM And I think the next step is to check those key cylinder and door ajar switches. Maybe disconnect them one at a time, then allow 10 to 20 minutes for the BCM to power down. Let me know if that helps.

Expert:  Chris replied 2 months ago.

Several Snap on scanners with the older software will interface with that BCM. I know because I used to consult for Snap On years ago. Maybe you can find or rent an older one. Just a thought.

Chris