2005 GT that was in a front end wreck and now has no start no crank situation.

[Spence340]

Recently bought a '05 GT convertible wreck with 105,000 miles that does not run and I am trying to figure out what the problem is so I am hoping someone can help. Just about everything else on the car works fine, lights, fan controls, radio, windows etc all work the only thing that does not work is the convertible top and when I hit the ignition I hear a slight click coming from the passenger side fuse box which I assume is the relay. The yard guy said they jumped the starter and it cranked over so I am assuming the starter is OK. The car has an old Viper alarm which I don't think is the problem, I can activate the alarm by hitting the panic button on the fob. I called Viper and they said the remote start is activated by holding down the lock and unlock buttons so I was hoping that would work but nothing happened. The car does have the factory alarm but I don't think that would interfere with starting the car even if it was compromised. Any info would be appreciated as I am getting pretty frustrated with this dead car.

 

[Spence340]

A lot of what I am seeing out there relating to problems like this indicate it may have something to do with the SJB (small junction box) so I guess I will start there and see what I find.

 

[whitmanink]

id look at the sjb ,. and also the kill switch by your brake peddle, that may be in,and not letting the car start, ,,second id almost try to remove the viper alarm incase thats doing something as well, but seeing as most things work ,, id say its the sjb , or relays within it,, maybe you will get lucky and see a burn or corrosion on the sjb and clean or replace it ,,

 

[stkjock]

cranked over at the yard... but did it run?

did you check the inertia switch? particularly if there was a crash. IIRC, it's in the driver foot well on the left side.

Also, possible PATS issue, how is the red security light flashing?

 

[Spence340]

Yes, cranked over but I am sure it didn't run. Don't know anything about the inertia switch but I will research it and check it out for sure. The aftermarket alarm light is blue and not flashing now although it might have been before I changed the battery in the fob. I don't remember seeing the red security light flashing now that you mention it, I will check it out.

 

[Spence340]

Pulled the SJB and there is a small amount of green corrosion in some areas so I will clean it and see what happens, I’ll check all the relays too. I pulled a couple SJB units out of junkers at the yard too and they all seem to have a little corrosion on them.

 

[Spence340]

Whitman, you mentioned a kill switch by the brake, is that a stock thing or something the alarm guys would have put in. I’m not familiar with that switch or what it looks like. Makes sense if you were in a front end accident that you would be pounding on the brake pretty hard before impact. The car is still at the yard so I don’t have immediate access to it but I need to check that.

 

[whitmanink]

im talking about the inertia switch,, next to your left foot near the brake .. its a red botton u cant miss

 

[Dino Dino Bambino]

A bad clutch safety switch (manual transmission) or a bad neutral safety switch (automatic transmission) wouldn't even allow the engine to crank.
The fuel pump inertia switch you're referring to is behind the driver's side kick panel. If that's been tripped by a collision, it'll allow the engine to crank but it won't fire.
A front end collision could have also damaged the crank position sensor or the wiring to it. That would also cause a crank but no fire situation.
Finally you might want to check the integrity of the engine ground cables.

 

[Spence340]

I’ll check the ground cables but not really sure where they are besides the battery ground cable. Will check the inertia and crank sensor when I get it cranking. The neutral safety switch is something I have thought about and need to get under the car and take a look. I’ve tried staring in park and neutral and sliding the the shifter a little as I crank but no go.

 

[Juice]

You can monitor pcm live data with Forscan. Check the safety switch operation, crank request. I find it easier at my age than hanging upside down under the dash with a dvom. lol

 

[Spence340]

Yeah, unfortunately Forscan is a little out of my league at the present time. Just watched a video on YouTube on it and someday I would like to get into it. I did just buy a OBD2 code reader from Harbor Freight Tools (ZR15S) which appears to be their top of line unit so I will see where that goes. Reading the manual I see a reference to Innova so that’s who must make them for HFT. Is there anywhere I could reference all the abbreviations people mention? I read something here about a sequence that resets something with KOEO procedure and also PATS comes up a lot. Looks like it’s a dealer thing.

 

[Spence340]

Saw a video on YouTube where a mechanic had a mustang that just died while driving and he did a complete electrical check out that was pretty cool and it turned out that the ground wire was the problem for the no crank, no start. The ground wire was attached to the left head (drivers' side) on the very rear of the head and looks like a real pain to get at, in the video he used a super long 3/8 drive extension and he had the advantage of putting it on a lift, I will be working on the ground with the car jacked up. He just loosened it and then retightened it to get the ground back and I wish he had said what size socket he was using, looks like a 12mm or 13mm in the video.

 

[Autokyrios]

That driver's side ground between the engine and firewall is a royal pain to get to. When I upgraded my alternator I made new ground wires and after fiddling with that for a few minutes I said "fk it" and ran a new ground on that side. Ran with that for a while until I had a bunch of stuff taken out over there and was able to reach the factory ground location. At that point I made a new wire to put in there just so it would be more normal.

 

[DieHarder]

You can use a set of jumper cables to test for ground issues. That's how I found out I had poor grounds. Just connect one end of a cable to the main ground on the passenger strut tower and the other end to an engine bolt (especially a mounting bolt for the alternator). If the output from you alternator increases one or more of the grounds have issues. The passenger side firewall ground is a common problem.

The other method (a little more scientific) is to use a VOM on VDC and test from the main ground on the passenger strut tower to various points on the engine and also from point to point on the engine itself ((also called testing for voltage drops) i.e. test from the body of the alternator to other points on the engine). If you see voltage you have poor grounds. You can try cleaning ground contacts but I found I needed new battery cables and had to add an extra ground from the body of the alternator all the way back to the passenger strut ground (using 4 gauge cable). This fixed my low alternator voltage issue. Hasn't been a problem since. Never did go after the driver's side firewall ground. The bottom bolt is just too difficult to get to (or I'm just too old now). Maybe one day.

 

[JC SSP]

had to add an extra ground from the body of the alternator all the way back to the passenger strut ground (using 4 gauge cable).…

So you have a pic of this custom ground cable?

 

[DieHarder]

had to add an extra ground from the body of the alternator all the way back to the passenger strut ground (using 4 gauge cable).…

So you have a pic of this custom ground cable?

Yeah, I do. I used a 4 gauge 100% copper stranded cable which ran from a mounting bolt for the alternator and ran along the driver's side wiring loom for the head; and around the back of the engine to the passenger side strut ground point. I also added a small 10 gauge brown wire from a ground on the body of the alternator to the mounting bolt for the alternator. This ensures everything is grounded at the same potential. Your installation will probably be different (I have a DOB setup). Just ensure the major grounds run back to the strut tower and you should be fine.