Need help electrical issues I have multiple warning lights on 2007 Shelby mustang gt.

[Friscoshelbygt]

I have multiple warning lights lit on my gt. Parking brake, tire pressure, traction control, and oil pressure lights all on. My fuel gauge stopped working and the air conditioning doesn’t work. The battery gets drained in less than two days if you don’t run the car. Does anyone know what could be common with all of these issues? Radio, windows, and all the lights are working.

 

[Blue03Cobra]

Sounds like the junction box has been compromised (water damaged).

 

[86GT351]

Could be a bad cell in the battery, Alternator, Smart Junction Box or other items. First thing to check is to see if the 2 cowl drains under the hood are clogged. If they get clogged which is common especially on the passenger side the water off the cowl does not drain outside the car. It actually goes into the Cabin Air Filter Box and then to the Smart Junction Box. The SJB can get water intrusion and create all kinds of issues. It would need to be replaced. If you remove the passenger side lower kick panel and visually inspect you might see signs of water intrusion. The below picture is of the cowl drain

 

[massacre]

+1 on cowl drain, it happened to me and luckily i was able to remove the SJB and remove all the moisture from it. Don't sleep on it, finding a new one can be difficult

 

[Friscoshelbygt]

I appreciate your guys replies. The SJB has never been wet and looks brand new. Is there any tests I can run to see what could be the problem?

 

[86GT351]

I appreciate your guys replies. The SJB has never been wet and looks brand new. Is there any tests I can run to see what could be the problem?

Sometimes you might need o unbolt it from the kick panel to get a better look at it.

 

[DieHarder]

I have multiple warning lights lit on my gt. Parking brake, tire pressure, traction control, and oil pressure lights all on. My fuel gauge stopped working and the air conditioning doesn’t work. The battery gets drained in less than two days if you don’t run the car. Does anyone know what could be common with all of these issues? Radio, windows, and all the lights are working.

Of the things you mentioned it's a good idea to check the following:

Alternator Output - If you have a VOM (Volt/Ohm/Amp) meter check the voltage output across the battery with the engine running. If not around 14.5 - 14.7 you need to figure out why (Alternator/cabling/grounds).

Grounds/Pwr Cables - What is the condition of the grounds and power cables? Clean/rusty/oxidized (do copper power cables have a green patina)? The main ones are in the engine bay but there are also several grounds behind the dash. If your alternator voltage is low you might improve performance by cleaning the ones you see in the engine bay and then recheck voltage. The best fix is to replace the battery cables if you can (last time I checked they were still available). I replaced mine and voltage output increased by almost 2 volts.

Current Drain - Need to chase down where that current drain is coming from. Usually not too difficult if you have an Amp Meter. Plenty of UTube vids on how to do it. Most likely suspects include the radio system/amps for the speakers or aftermarket additions like LEDs or other mods that turn into self inflicted wounds. Temp fixes include removing fuses once you find the offending system and/or returning the car to stock (get rid of the add ons; especially the LEDs) unless you're able to keep her on a trickle charger.

Smart Junction Box - In Ford lingo it's called a Multifunction Electronic Module. A common suspect as Blue Cobra points out is the SJB. It often gets wet either from the passenger cowl drain or the passenger window seal perishing (the one behind the black window strip that runs around the top of both windows). Simplest check is to pull the SJB (passenger footwell) and note the condition of the connections & board. If you find evidence of water/corrosion some have had success restoring it to normal operation by cleaning all of connectors and terminals. Otherwise, you're looking at a replacement. If you have forescan you can get a lot more info out of it.

SJB: Multifunction Electronic Module: https://iihs.net/fsm/?d=419

Removal: https://iihs.net/fsm/?d=422&f=Smart Junction Box (SJB).pdf

 

[Juice]

Number 1 issue is the battery. Without a fully charged and good battery, tests produce unreliable results.
Disconnect negative cable and charge the battery. Confirm charge with volt meter. Should read 12.6v - 12.8 fully charged, nothing connected.