Difficulty starting vehicle in morning when cold due to battery mounted in trunk and previous owner installed a relay solenoid to keep fuses from popping

Asked by Cjscar2 Feb 12, 2019 at 02:31 PM about the 2001 Ford Mustang SVT Cobra Coupe

Question type: Maintenance & Repair

So I recently purchased a 2001 Mustang Cobra SVT from my buddy.  He mounted the battery in the trunk.  He used big gauge cables from the battery to the alternator and starter.  He also installed a starter relay solenoid in the trunk with in line fuses between the starter and the relay.  The battery is a brand new Optima and I also had the aternator tested.  I can hear an audible clicking in the trunk my guess is the relay is arching.  I try to start like 20 times in the morning when it is cold.  After vehicle starts and warms up the vehicle starts every time.  The guys that tested the Alternator and checked out my system said that I need to replace the relay solenoid with a high performance continous realy.  I checked on every website available on the internt and I have not been able to locate what they suggested.  I spoke with some of the guys that work for Jegs performance and they said that they had no idea why there is a relay mounted in the trunk?  I contacted the previous owner and he said that he put the relay in there because The actual relay in the trunk is due to the initial power requirement when starting the car.  Too much power spike when trying to initially start the car can cause fuses to blow. The car had no engine work, and didn’t require the solenoid in the trunk for any other reason tham being able to control starting the car with the length of power cable needed to relocate the battery.  That being said the last guy I spke with from Jegs performance suggested that I by pass the relay and wire directly to the batterty to see what happens.  Any food for thought would be greatly appreciated.  I am getting ready to transport the vehiicle from Hawaii to Florida and if the car does not start when I drop it off then the company will not load vehicle on the ship?

2 Answers


Without an exact wiring diagram of what the previous owner did I could not advise you. It is not normal to install a relay on the big wire going to the starter. He may have installed a much too small relay which could lead to arcing. I suggest you find a competent automobile electrician to sort things out.

Your Answer:

Ford Mustang SVT Cobra Experts

  • #1
    Christopher Ihara
  • #2
    Tracy Hooks
  • #2
    Michael Kane
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