Intermittent starting problem, puzzling

[Alec]

And yes, I've used the search feature to try to help!

Anyway, sometimes my truck doesn't want to start. Plently of power, fuel pump on, etc. If I jumper the starter solenoid that's on the fender, it works. So I figured the solenoid was bad and I replaced it but the problem came back. Turns out the solenoid doesn't always get a signal to start. So therefore the problem is somewhere between the key and the starter solenoid. A few things come to mind: alarm, ignition switch, or wiring. Keep in mind this is intermittent, about once a week.

Rather than troubleshoot the problem further, spend lots of money, and have lots of headaches, I thought of adding a pushbutton for the starter in case it fails again. Keep in mind I'd rarely use it, so I'd put it somewhere hard to get to and not accidentally touched.

QUESTION: So all I need to know is: does the ignition switch just send 12V to the starter solenoid, or something else? If so, I'll just tap power from somewhere and run the switch inline to the starter solenoid.

Thanks for reading!

 

[Zer0LUXX]

There is a safety sensor (i can't remember the correct name of it at the moment) in the starting circuit that won't let the vehicle start if it's in gear. Maybe its that sensor that's going bad?? Neutral safetly switch might be close to the name?? Just a thought....

 

[410Fortune]

Alec, yes the red/blue wire is a 12v signal.

I had this same problem on my truck, when it was hot it would not start, or if it did not turn over on the first bump the starter would not bump again. I too replaced the starter solenoid, no change.

However I was getting a signal to the solenoid with every turn of the key, I checked this with a test light.

The problem on my truck turned out to be loose/dirty connections and wires at the starter itself.

The 4.0L starter has a built in starter solenoid, if it doesnt get enough juice it wont turn over, When you arch the starter solenoid you are sending WAY more volts to the starter then it gets normal, thats why it works every time.

I took my starter down, ran new wires (the small signal and the large direct to battery wire) which also allowed my to re-route them where I want them (away from headers and heat, right down back of engine with tranny harness) I then soldered on new wire ends down by the starter (old ones were crimped on) and then I also heat shrinked the small signal wire and crimped it onto the starter nice and tight. Cleaned up all the bare metal with an emery board.

Problem has been gone ever since.
I was about to buy a new starter, no need.

If your problem is in the ignition then a button like you described would be perfect, however I would check these things first as it canbe decieving. It takes X amount of power to get the starter solenoid (the one in the starter) to switch over, if it gets anything less it will not switch over, leading people to believe the problem is up stream.

Have you checked the 12v+ at the red/blue signal wire to the solenoid (fender) with a test light? Should light up every time you turn the key to start. I just put one side of my test light to the signal wire, the other side to ground, set it up so I could see it under the open hood and tested it myself. I too figured it was in my key switch seeing as how my truck has 230K miles on her....

 

[Alec]

while I tried to start it with the key, a friend was testing the red signal wire with a test light. About 1/3 of the time the test light didn't light. So what I'm gonna do is just find any old 12V lead, put a heavy duty switch on a wire, and run that wire with the stock wire to the fender solenoid. Thanks for the answer! Hmmm, dunno if I'll hide the switch or make it cool

 

[BUCHVILLEMAN]

1) went through exact problem replaced selnoid. had alternator tested and started tested ended up being poor connection between selnoid and battery. cleaned connections and all seemed well started doing it agian and then battery overheated on way to work and lef tme stranded. never got a good answer as to what happenned but replaced battery and all things seemed to be corrected.

2) i replaced key ignition on my riding lawn mower just yesterday witha push button. i dont see why you could run a second line off starter and second line off battery to meat up and connect at the button. i got a nice big chrome button that is very stout. goes to a tractor. button width is about size of a quarter.

around here the discount auto will do free electrical test that include sel, start, alt, and batt.

 

[410Fortune]

I would make it a "secret"switch because it will allow you to bump the starter at any time.
UNless, you wire it in (like you said) using a ACC power wire, then the key has to be in the ignition turned to on (not start, just acc on) that way the button wont work unless the key is in.

I would wire this switch directly into the power distribution box under the hood, thats where I get the acc feed for my PIAA and KC light switches, my CB radio, and a few other gadgets. This way I cant leave allthat crap on and kill mybattery. I ran 1 10 guage wire into the cab from the power dist box for all this stuff...

If you want to make it really cool go get one of those ignition switches, where you have to flip up the red cover, then you can hit the switch.......

 

[Alec]

I just went to autozone and got a heavy duty pushbutton switch, an inline fuse (30A enough just for the signal wire?) and some connectors. I'll find a good lead from the engine fusebox like you said; run it through the inline fuse to be careful; in to the switch; then a wire to the solenoid that will branch into the stock wire at the solenoid.

I'm no stranger to wiring, so I should be able to knock it out in about 15 minutes. I have some other wiring projects, so I'll do them at the same time.

 

[410Fortune]

You dont have to tell me! When I re-built my underhood harness for the 4th time I put a couple of large plugs on my underhood power distribution box, I can now take it all teh way out of the truck in 2 minutes. this is great for my truck because as you know it is a converted 4.0L so I only have 3 relays and 3 fuses in there, allteh other junk was yanked out. Which means that anytime I wire in something, like lights, a fan, etc I have open spots for fuses and relays. really cleaned it up under the hood! I can unplug it, take it inside, clip in some new wires to the appropriate fuse location, tap into any power feed wires I need, and blamo! done!

I love it! The explorer power dist box is great! I would add oneof these to any vehicle I owned if I plan to add aftermarket stuff (shhhhh dont tell the Jeep crowd or they'll be stealing more Ford parts from the yards)

If I ever get this one full (never happen, I have like 20 open fuse spots) I would add a second box for more!


30 amps is overkill for that wire, 10-15 is more like what it needs. Any solid red wire in that box is ACC power from the computer (Switched power with key in on position)

 

[dogfriend]

not trying to spoil your fun, but...

Have you considered using a remote starter switch?(they are made for starting or cranking when under the hood). When your truck won't start you clip one lead to the bat + terminal and the other to the 12V terminal on the starter relay on the fender.

This way you can store it inside so that other people can't use it to start your truck

 

[Alec]

I just hooked up the starter switch this morning. I tapped the rear window defroster fuse under the hood for power; added a 15A inline fuse; ran it into the truck to the switch which is located close to the center console, under the dash a bit; and joined the negative from the switch to the stock ignition signal wire.

It took me longer than I thought, about 45 minutes; because I couldn't get the darn wires through the firewall at first. I just have too many there already!!!

Unfortunately the pushbutton is not ignition controlled. I guess the ignition control for that circuit is somewhere downstream of the distribution box. But you still need the key on to get fuel to the motor, so it's all good.

 

[DonM]

Sorry to dredge this thread out, but I have a question Alec. Did you ever find out what the problem was?

Sounds like what is going on with my Ex and I need to take the power distribution box apart and take alook inside.

 

[Alec]

Part of the problem is still a mystery: gremlins.

However, the main problem I found was the tranny "park" lockout. This normally prevents the truck from being started if the tranny isn't in P or N. My tranny and shift linkage were both messed up and fixing them mostly fixed the problem. Still happens about once every few months through, but with that starter button it's not a problem.

 

[DonM]

Thanks Alec, Im pretty much in the same boat. Once a week this happens and I cant figuare it out.

I replaced the FPR today and I hope this fixed the problem? If not, the Ex has 100,000 miles and it would have needed replacing soon anyway.

I'll find out in a week or so...

 

[schock1]

Hmmm, I had the same problem along with momentarily losing power to my stereo & I simply replaced the ignition switch & all is fine. A simple $12 fix.

 

[DonM]

Originally posted by schock1
Hmmm, I had the same problem along with momentarily losing power to my stereo & I simply replaced the ignition switch & all is fine. A simple $12 fix.

Simply replaced? Exactly how long and how hard was it?

Dont you have to get in the stearing colum?(SP)

 

[schock1]

Mine is a '93 XLT 4x4

It's actually fairly simple, the only pain is to reach the two nuts holding the switch on but, I did it with a ratcheting wrench w/minimal problems. I removed the two screws (torx) on the back of the steering wheel, removed the steering wheel bolt & extracted the wheel with a steering wheel puller. Be carefull when taking the steering wheel cover off, the wires are connected at the top with a pinch type plastic connector. I used a pair of needlenose pliers to release it, then unplugged the electrical connection.

Remove the small round cover at the front of the collumn, then remove the upper & lower collumn covers that are held on by two philips head screws.

Next get your flashlight & wrench ready. Shine the light through the space on the left hand side of the collumn & you will see 2 nuts, those hold the switch down. (they may be metric but, 7/16 wrench worked)remove the nuts then reach around & underneath on the opposite side, lift the switch & pull the wiring down. You should be able to get it down far enough to plainly see what you are doing. Unplug the old switch then plug the new one in, leaving the small metal retaining wire in tact (this keeps the switch in position untill you get it secured to the column & back on the hook). Obviously, you will have to move the retaining wire a bit to plug it it, just keep it in the side of the switch.

Shove the switch back up under the dash the same way it came out. Getting the hook to seat is a bit tricky but, I finally got it very easily once I decided to go ahead & place the switch mount back on the column & secure it with the nuts. Only put the nuts on far enough to keep the switch from coming off, this will leave you enough room to position the hook back into the switch. you should be able to move the hook back & forth a little with your finger, you can move it up & down by turning the ignition w/the key in it. Just make sure that when you tighten the nuts down, you have the switch & ignition back into position. once you get everything lined up & in place, finger tighten the nuts so that you can still move the switch up & down. Push the switch downward by turning the key slightly as if you were going to start it, then tighten one of the nuts down (the bottom one is the easieast to tighten). Once you have tightened it, take the retaining wire out of the switch & test it. Make sure you can turn the ignition backwards to get ACC, if not, you will have to loosen the switch & shove it a little farther forward. Good luck, it's not as hard as my directions are long, I just broke it down to barney level.

 

[Alec]

Damn, thanks for that writeup!

 

[DonM]

Yeah thanks!!! Hope ya didnt go to alot of trouble writing all that?

Thanks again I will look into this when I get a chance.

 

[schock1]

No problem, I've gotten a ton of assistance from this board so I'm just trying to give back a little. Besides work is a little slow today. I needed something to do while I pass the time drinking my coffee.

 

[DonM]

HeHe, yeah me too! This board has been more then helpfull. Ive learned alot here in the last few years and now i find myself helping others.

Im gonna check into the Ignition switch. Even the CPS could cause my problems and I havnt replaced that yet. Maybe Wed?