So SJB might be going out.

[07 Boss]

I haven't looked into it yet because it happened on my way into work this morning. I went t o turn my headlights (cheap HIDs) and they flipped on for a split second and cut out. No biggie I thought, turned on the fogs and went on my merry way to work. I get here and go to set the alarm and locks, and no horn honk. I open the car and try the horn, nothing. Hmmmmm....

First instinct is SJB water intrusion but I live in Vegas. Probably rains 6 days a year here. I never thought the water intrusion would be an issue so what else should I look at? Do they run off the same fuse? I just have a feeling I'm not gonna find anything wrong with the SJB corrosion wise.

Should I have put this in the tech section?

 

[redfirepearlgt]

Assuming you wash the car with water (some use waterless cleaners in drought areas) water can still get trapped and find its way in. I never realized why, but when I had my 05 I noticed when I washed the car, I would hear water hissing as it seeped past a large oval shaped plug in the fire wall on the driver's side. I pulled this plug out and water came shooting out. So each time I washed the car I would pull that plug. Years later after the car is gone I learn about the plugged drain holes from this site. Prior to that back in the day of the cars being new, it was blamed on the grommet where the antenna enters the car. No one thought of clogged drain holes in the cowl/firewall area until later. Thankfully doing that may be why I never had an SJB problem. Sometimes ignorance is bliss. LOL!

 

[46addict]

I would make sure the underhood BEC fuses are good before looking at the SJB. The horn has its own fuse so it's unlikely for both headlight and horn fuses to blow at the same time, but it doesn't hurt to check.

 

[07 Boss]

And I just had to run out for a second and the alarm chirped when I hit the fob. I pushed the horn and got a peep. I wouldn't call it a beep, then nothing. Now I do have to say I was having horn issues before, but it was never out. When I moved them the horn/s were pointed forwards instead of down and they sounded off, probably because too much crap got in there, but they sounded. The intermittent horn leans more toward the box. I thought that I was immune because of the lack of rain here. I guess not.

 

[redfirepearlgt]

Horn relay still routes through the low current board on the SJB to provide ground to energize the horn relay in the BEC. Fuse is good since it beeped at you.

F46 feeds the horn via the Horn relay, both found in the BEC as mentioned. The control side of the relay (the coil side) obtains ground through the horn switch on the steering wheel via the low current board in the SJB (in connector C2280B pin 39 and out connector C2280C pin 29). Internally the SJB chirps the horn via the keyfob through that internal circuit according to the prints. You're still on the right track with the multitude of intermittent failures you are seeing IMO.

Good luck.

 

[07 Boss]

Horn relay still routes through the low current board on the SJB to provide ground to energize the horn relay in the BEC. Fuse is good since it beeped at you.

F46 feeds the horn via the Horn relay, both found in the BEC as mentioned. The control side of the relay (the coil side) obtains ground through the horn switch on the steering wheel via the low current board in the SJB (in connector C2280B pin 39 and out connector C2280C pin 29). Internally the SJB chirps the horn via the keyfob through that internal circuit according to the prints. You're still on the right track with the multitude of intermittent failures you are seeing IMO.

Good luck.

Thanks for the detailed info. I will give me direction this evening as I investigate.

 

[redfirepearlgt]

If you find corrosion in the connectors its best to clean them with an acid brush (trim the bristles down about half length and at an angle) and Isopropyl alcohol (90% or higher purity). Don't dunk the connectors. And I do not recommend using contact cleaner as many of those products aren't designed to be used in ABS or other plastics and will damage them. Use canned air or an air compressor and gently blow dry. Then leave them overnight before plugging back in. Conductive grease? Not needed. Few applications have I seen where it is ever used in any line of electro-mechanical, electrical, or electronic line of work I have been in. Doesn't mean there isn't a use for the stuff, just not anywhere I have really found in my 30+ years of troubleshooting, installing, and maintaining stuff.

 

[07 Boss]

Didn't get a chance to look at it last night but the horn works again, lol.

 

[redfirepearlgt]

What about the headlights? Did they start working again as well? The fog lights are also controlled through the SJB FYI. A signal from the SJB energizes the Fog lamp relay in the BEC. Same for high beams when your headlights are on. Headlight low beams are controlled directly by the SJB from the headlamp selector switch. Either you have water in that box causing connection issues, a rodent has been chewing in that immediate area that has caused a wiring issue, or the SJB has simply decided to begin taking a dump. Friend of mine up north of me lost his and there was no sign of water intrusion. It just went bad on him. One morning the doors just quit locking/unlocking with the key fob, but he could pop the trunk with it. He tried a new battery in the fob to no luck. Turned out to be the SJB.

 

[46addict]

Yikes. The SJBs are $300+ items for OEM. Are refurb/aftermarket units ok to use?

 

[redfirepearlgt]

Just checked with a friend of mine who had to replace his and he got his from TASCA new OEM. I don't have any other 411 on a purchase aside from that. He did tell me that there is a place in GA that sells them salvage for about half of what he paid TASCA for one ($325 new OEM). He chose new over salvage for no specific reason mentioned.

I'll post the name of the place when he gets back to me.

 

[ponys197]

When replacing the SJB with salvage you will need to find one that is as close to your vehicle as possible with year , make , options as you can. You still have to have the salvaged one flashed and that will cost you at least $100 on top of the unit.

https://www.hollanderparts.com/ is a place you can check by year and model and then fine one that matches close to yours.

I chose Tasca OEM over salvage due to the fact that buying salvage at say @$150 and flashing it for $100 didn't seem worth not having the piece of mind to have a new one from Tasca that was warrantied.

Luckily I had Finishline Performance close to me for flashing it versus having to take it to the dealership , who by the way want $866 to replace / flash an SJB from them.

I had the similar issues like you had where it would go away and then come back . Even if you replace the SJB you need to try and leak test the car in that area according to the Ford TSB (which Finishline provided me for reference). If you don't fix that , you will eventually be in the same boat again.

And just for the record I did purchase a salvaged SJB from the place but my problem went away long enough i thought i was okay and I sold the unit to someone else needing one and recouped my cost. He used it and got it flashed and it fixed his issue as well so both methods will work just depends on what you are comfortable with.

 

[BMR Tech 2]

I ordered one from Midway Mustang on eBay I think. Great price and the SJB looked brand new. It was out of a 2008 GT500 with like 10k miles on it. You may need to have the SJB programmed for proper function though.

 

[redfirepearlgt]

When replacing the SJB with salvage you will need to find one that is as close to your vehicle as possible with year , make , options as you can. You still have to have the salvaged one flashed and that will cost you at least $100 on top of the unit.

https://www.hollanderparts.com/ is a place you can check by year and model and then fine one that matches close to yours.

I chose Tasca OEM over salvage due to the fact that buying salvage at say @$150 and flashing it for $100 didn't seem worth not having the piece of mind to have a new one from Tasca that was warrantied.

Luckily I had Finishline Performance close to me for flashing it versus having to take it to the dealership , who by the way want $866 to replace / flash an SJB from them.

I had the similar issues like you had where it would go away and then come back . Even if you replace the SJB you need to try and leak test the car in that area according to the Ford TSB (which Finishline provided me for reference). If you don't fix that , you will eventually be in the same boat again.

And just for the record I did purchase a salvaged SJB from the place but my problem went away long enough i thought i was okay and I sold the unit to someone else needing one and recouped my cost. He used it and got it flashed and it fixed his issue as well so both methods will work just depends on what you are comfortable with.

There ya go. Thanks for posting G. Couldn't remember why you went OEM new. FINISHLINE FTW!

 

[46addict]

Just checked with a friend of mine who had to replace his and he got his from TASCA new OEM. I don't have any other 411 on a purchase aside from that. He did tell me that there is a place in GA that sells them salvage for about half of what he paid TASCA for one ($325 new OEM). He chose new over salvage for no specific reason mentioned.

I'll post the name of the place when he gets back to me.

Could it be The Parts Farm?

edit: Is ponys197 the friend you were talking about? Never mind lol.

 

[redfirepearlgt]

Could it be The Parts Farm?

edit: Is ponys197 the friend you were talking about? Never mind lol.

Yeah. I got home from work and started to post because I see you are from the Peach state and thought it may be of use to you and saw he had already posted it.