Hey Gang,

Recently my 99 F150 5.4L 4x4 has developed a small problem starting. When I turn the key to run, nothing happens for anywhere from 1-3 seconds. Then, while I hold it there, it will suddenly crank, start, and idle just fine. I am worried that something is about to go bad, and I wont be near my home when it happens.

I can hear the relays in the dashboard clicking, so I believe I am OK as far as the ignition switch goes. The next step should be the starter relay, then the starter itself.

I have ruled out the starter being defective. It works fine. When it receives voltage, the plunger pushes the bendix out and starts the truck. It just isn't getting voltage at the right time.

Does this sound like a battery issue or a starter relay issue?

Thanks for the help. If I left out any info please let me know.

-Steve

 

I would say check the voltage at the starter motor relay from the key, and see what you have there.

Have the meter on the terminal from the ign switch ( via the DTR ) and ground, turn the key to the start position. You should have + DC as soon as you get to the start position.

I would have thought, from the description, that this was a ign switch, DTR, or Starter Motor relay issue.

Not sure what relays you here clicking in the dash.

 

Well im not 100% on anything, except that the starter works when it gets voltage.

I believe the relay(s) in the dash that I hear simply energize the starter relay, which in turn, activates the starter.

Maybe today or tomorrow I will have the battery tested, just in case. Thats free almost anywhere.

THANKS.!

 

No relays in the Central Junction box ( CJB or Cab fuse panel ) have anythign to do with activating the starter.

The key when in the start position sends power to the Clutch Pedal Position Switch jumper ( or the CPP in a manual ) to the DTR ( Digital Transmission Range ) Sensor to activate the coil in the starter motor relay mounted on the pass side of the firewall in the engine bay.

The Starter motor relay should have 3 or 4 wires on it ( the ground might not be a wire on your MY, just a metal tab ).

A 16 AWG Tan w/ Red stripe wire and 2 large AWG red wires.

The Tan w/ Red stripe wire is what you need to check for voltage on when you turn the key to the start position.

If you can get the meter on the wiper cowl, with an alligator clip on the Tan w/ Red stripe wire, and ground, this is what you want to see go to => 12.6 V DC when you turn the key to the start position.

If it does, I would think there is a problem with the Starter Motor relay

 

The one problem I think I would have checking any of this is that after I start it and it runs, the problem doesnt repeat itself until the next day (or maybe a few hours later.)

THIS is what leads me to believe that its a moving part (relay) or the battery. Batteries act weird sometimes, in my experience.

I will hook up my meter to that very wire before I try to start it for the first time in the AM. Luckily it isnt my daily driver, I can take the battery and starter out really quick and have them both tested as well.

Thanks for your help!

 

I would not bother testing either of those right now.

You know the starter works normally.

If you want another quick test :

1. Turn the key to the on position ( not start ), and wait for the theft light to go out.
2. Apply + DC to the Red w/ Tan terminal on the starter motor relay.

The truck should start.

This removes the ign switch, DTR from the starting process, the truck should start to turn over as soon as you get power to that terminal. Make sure you can remove it quickly and watch for moving parts on the engine.

 

Gotcha. If the relay starts the starter solenoid right away, the problem is somewhere between the ignition switch or DTR. If it hesitates to start like it has been, its the relay. Ill do that next time it's remotely nice out

 

That is my thought exactly.

Please keep us updated on what happens !

 

What Scully told you is dead on, but just to throw 1 more perspective into the pot. An additional way to check the starter solenoid is to remove the 2 red heavy cables from each side. Jump hot to the actuator wire and check ohms on the 2 poles you took the heavy red cables off of. Low resistance, good, high resistance, bad. I'm betting it's the solenoid. (relay on firewall) When you have the 1-3 second delay the resistance is heating the contacts up and causing it to eventually make enough contact through dirty, burned contacts.

 

Havent had time to check yet. It's been rainy or I've been busy, but just so I know, is it easier to get to the solenoid from the hood or from underneath the truck?

 

What I am posting about it the Starter Motor Relay on the firewall, passenger side.

 

Got it. I guess I will follow the battery cable to it, definitely find it easier that way 8-)

 

Here is a picture of it on the firewall from another member's thread.
It has some wires mistakenly added to it



This is the 1997 EVTM page, shows the same layout as the picture above



Your configuration might look like the 2000 + MY trucks ( can't recall on this in the 1999 MY right now, '99 was a MY that has a lot of the 2000+ electrical changes, but some things were still like the 97-98 MY sort of a morphing MY with a little from each design range )

 

Yep. I found it before I even saw the picture.. mine had a cover over it though.

Anyway, when I connected 12V to the terminal that the tan/red wire was on, the engine started. Ofcourse, one test wont do it. Ill try again first thing in the morning, and periodically.

On a side note, would my ABS light being on have anything to do with any of this? I highly doubt it, but my ABS light has been on since I first noticed this starting issue. Just throwing it out there, maybe missing something..

Thanks again for posting the pics!

 

Steve, I don't like coincidences. If the ABS light problem sprang up with your starting problem, I'd suspect some kind of relationship. I don't have a wiring diagram for your truck, but I'd at least investigate the possibility the two are related somehow.

- Jack