Better Beaters - Building Cars and Daily Drivers

 My Daughter moved her car 120 miles away.

Another Chapter in the saga. I'm starting to lose count!

I thought and certainly hoped that after the transmission rebuild that I would have a trouble free period with the car. It was a good couple of months. Then the text came, funny problems with the car!

My Daughter had called and reported that during her lunch break, after sitting in the parking lot with the engine running, a/c on, and listening to the stereo, that when she shut the key off, the in dash multi disc cd player began shifting through the discs, as if to eject them. This was with the key off! Repeatedly hitting the radio switch and turning the key off and on didn't affect this. She tried to start the engine but it just made some weak clicking sounds. She had to return to work so the cars sat for a few hours. 

After work she tried to start the car and was successful, driving back and parking it at home. Later the car would not restart. Then she called me to let me know the situation. 

This was an odd symptom, something that I had never experienced during my prior ownership of the car.

I started searching the Internet and found a lot of related threads in various Mustang and Ford forums. I discovered that this was a common condition. There were also comments that other systems were displaying odd symptoms. However I focused on the cd player. The cure was stated to be disconnecting the battery terminals and performing a "hard reset" by touching the battery cables together, This was supposed to discharge any memory systems in the electrical system so they could be started clean. 

This concept of the hard reset would be well known to any Jaguar fan that has been involved with forums over time. It seems that Jags built after 2003 are notorious for electrical gremlins, usually related to weak batteries. Their electrical systems need a minimum of 12+ volts to function properly. Many Jags are not everyday cars, and as they sit, their batteries lose voltage, due the drain of  maintaining memory systems in the car. A lot of owners keep battery maintainers hooked up to keep the battery topped up.

My Daughter knows enough about cars to know that the alternator supplies the electricity to charge the battery and asked if that could be the problem. The starting issue was the only one that presented itself so that was all I considered before driving up the next day.  

When I arrived I checked the resting battery voltage with both terminals connected. It showed 11.77 volts on my multimeter. Then I disconnected both cables and measured the battery voltage again. It was the same. After performing the hard reset, I started the engine, without a jump,  and recorded 13.8 volts with the motor running, which indicated that the alternator was working. 

My conclusion was that since she lives only three miles from work, the battery doesn't have enough time to recharge the battery after starting, especially since she was using the lights, stereo and a/c. She  had been on vacation for a week so the car had not been used for some time. She also mentioned that it sometimes took two tries to start the motor, that thought registered, but I didn't think that the fact was too relevant. I thought  that I'd drive the car for a while to charge the battery. I decided to drive to Sacramento Vintage Ford, an antique and hot rod car shop.

When I arrived I left the car running and opened the hood to check the running voltage which was over 13 volts. When I shut it off the resting voltage was over 12 volts, so it looked like it was okay. The car restarted and I drove to a nearby gas station/car wash. I put some gas in, bought a car wash and restarted the car and put it through the wash with the engine running. I drove "home" with no problems, the car felt great. After I arrived I rechecked the battery and alternator once more with positive results. 

The advice I offered learned from the forums was to turn the radio off before turning the key off. It was also suggested that the driver not depend on the "after shut off" accessory power.  I shared these insights with my Daughter before I left.

Now I felt great during my drive home. 

But of course, this feeling didn't last! At least I felt good during the two hour drive home!

The next evening I received a text that the car had been fine for a day and she had used the car to run some errands with no trouble. After work the problems started again. This time the car wouldn't start at first. The car started up but after driving a bit all the warning lights lit up, luckily she could pull into a parking lot. She called for her partner to get help and they managed to get the car started and it barely made it back to her parking lot at home. 

Back to the Web.

I spent a few hours reading about similar problems. The accessories, a/c, and windows not working, all warning lights lit up on the dash. It was determined that something called the SJB, Smart Junction Box was at fault. This is a combination fuse/body control computer located  behind the right front kick panel. All the accessory and body systems are controlled by this box. 

I learned that most problems were due to moisture getting into the connections. This moisture was due to water leaking in from the cowl area and dripping on the box. The leaks were due to poor sealing or a blocked drain. Usually the posters had complained of wet carpets and a damp smell. When the plugs were disconnected at the SJB, there was visible corrosion at the terminal pins. 

I never noticed any damp smell in the car even after I drove it through the car wash. 

Some guys had success drying and cleaning the connections. Some didn't. In that case the SJB needed to be replaced. One problem; these have been out of production for years and there weren't any "reconditioned" units available. My auto parts store told me that they couldn't order one. I even contacted the dealer's repair section. They advised me of the same. 

I watched a bunch of videos where the poster used one sourced from Ebay. I went to Ebay and check out some parts interchanges. 

After lots of research I learned that the important thing was to match body style to body style, ie; coupe to coupe, convertible to convertible. The option levels were important also, base as opposed to deluxe, which has more equipment and options. 

I went to a local Pick and Pull lot where I located several similar year Mustangs. According to their interchange, '05 &'06 units are interchangeable and '07 &'8 units are also, I noticed that one plug was different on the '08 unit that I removed. For the price of 40.00 I figured that it was worth a try. 

I had read that it was sometimes necessary to reprogram the unit to have it work properly. 

So far I was only out forty bucks, the cost of gas, and a lot of my free time.  What's a Father to do? 

I drove up again with the new/used SJB hoping for the best.