Hey Everyone, having a strange electrical issue on my S197 GT CS.

The Situation: I was installing an aftermarket head unit (Mekede DUDU7). The installation went smoothly, and I now needed to download maps for the Navigation apps I installed. which took some time. I suspect the door may have been left slightly open, because when I checked on the progress a few hours later, the battery was almost completely drained.

I boosted the car using a portable battery pack, and that’s when the first issue appeared: the screen would not turn off when I shut the car off. I disconnected the negative terminal on the battery and reconnected it.

I jump-started the car with a portable battery pack, but now the headunit has no power (screen is totally black). The HVAC blower motor/heater does start running when I turn on the car, despite the DUDU7 being off, but I cannot control it because the headunit is not operational.

What I've tried:

1. Swapped back to the OEM Nav and Shaker unit. The HVAC controls on the faceplate work, but the radio/screen in the OEM Nav itself is still dead and the radio does not work.
2. Checked passenger kick panel fuses #3, #14, and #39—all good.
3. Checked under-hood fuse #25—good.
4. Disconnected the negative terminal for a reset—no change.

Has anyone seen the 'fan stays on / radio stays dead' combo before? Is there a specific relay or a 'hidden' fuse (like the Accessory Delay) that I should be looking at?" Any assistance would be appreciated.
PS Happy Holidays.

 

Might Glean Some Info Here!

https://themustangsource.com/forums/...5/#post7079681

KC

 

As always, you are very helpful. I will continue my investigation with the info you posted. If anyone has any further thoughts or suggestions, I would be happy to consider them. HAPPY HOLIDAYS!!!

 

Well, I have tested the following fuses:

At the battery junction box (under the hood):
#20 #25 #33 #44 #56

Smart junction box (right underside of passenger seat)

#3 #7 #14 #28 #33 #39 #41

They checked and tested fine. I guess my next step is to properly test the cables connecting to the head unit to ensure power is getting there. I tested with a tester that tells me if the lines are live, but it did not work well with the car, it would not even show the cable leaving from the batter as live (it must be for AC only, although it did show the cables going from the converter to the laptop (dc current) as being live).

Any insights as to how to test the cables going to the head unit (i.e. which is ground and which is positive)?

Any further suggestions?

Thanks, and happy new year to all.

 

You Can Find Wiring Diagrams & Shop Manual Info Here!

I Can't Access My Normal Wiring PDF's At The Present!


Your Car is a 2013 Btw??

https://charm.li/

KC

 

Good memory. Yes. Thanks again for your kind and helpful response.

 

I Believe If You Want To Check For Power That Pin 1 on C-290D Is Always Hot & Pin 15 is Hot With Key On!

I'm No Electrician But That is What I'm Seeing in Regards To Checking For Power!

Depending on Setup Your Wiring May Not Have The Wires Listed on Pinout! Depends on System.


Not Sure if You Have Shaker or Shaker Pro! Did Not See 500 Reference!

I Was Fat Fingering My Logon! Got Into Wiring!

Hope You Find Some Use of PDF'S Supplied!

When Disconnecting Battery For Reset Allow At Least 30 Minutes For Complete Clearing I Have Heard! Just an FYI!

KC

 

Its a Shaker 500

 

Thanks for all the help. In the end it was the canbus for the new head unit. After the canbus was replaced, the new head unit is working fine. I did not test the OEM heat unit to see if it works. The canbus for the new head unit was not being used with the OEM head unit. My guess is that when the canbus for the new head unit died, it may have affected the computer in the car, and it needed instructions from a working canbus to reinitialize communication with the head unit..

 

Good News & Thanks For The Update!

KC