Starter Dead Short

[Joe Michaels]

Originally the truck was periodically continuing to crank after trying to start cold. I figured the solenoid on the starter is to blame. I replaced the solenoid and had the starter tested, Starter tested ok. Now it briefly acts like it wants to turn over but then all is dead. If I remove the starrter and reinstall sometimes it trys to start then goes dead. I tested voltage and get a dead short when starter is connected. I unhooked everything except large wire going to post on solenoid from battery. When wire is off the post on the solenoid (the one on the battery) I get voltage. When I touch the wire to the post dead short. No other wires are connected. Not the starter relay not the ignition. Not the small ignition wire on solenoid. I also replaced the ignition. This is the second replacement solenoid this week. I am assuming that the solenoid is sticking open. Could low voltage be the problem? Or is there a short in the starter itself. Pulling my hair out and I need my truck for work, Help. I have not replaced the starter yet as I don't want to spend 200 on a new one when the old one tested ok twice.

[NoRalPh]

What year is your truck?

The solenoid you're talking about, do you have one on the pass fender? (they don't all have that, depending on yr)

Are you talking about the Bendix on top of the starter?

Take the starter out, lay it on the ground, use jumper cables to connect to it. If it just "arcs" and won't spin, it sounds bad to me

[Joe Michaels]

Truck is a 1999, F350, SRW, 2WD, 7.3.

I usually refer to the "starter solenoid" as the one on the starter itself. To me the "starter relay" is the one on the passenger side fender wall under the hood.

So I finally decided it might be low voltage. I thought I had the batteries charged fully but apparently not. I made sure that I did this timee and it finally did start but it still wanted to keep turning over with the ignition off and the key out. I was not getting the short anymore however so I tried arcing the Starter relay on the fender wall. I did get it to turn over finally and then stop turning over when I removed the screwdriver I was using to arc with. So I suppose the relay could be part of the problem but I still think there is another problem. It only does this when I forget to plug it in and I have to keep cranking longer than normal to start it. That is when it sticks and keeps cranking and the only way to stop it is to remove all battery cables from the batteries. I guess the low voltage was causing the solenoid on the starter to stick in one position??? I have had this problem before and never have beeen able to completely resolve the problem to my satisfaction turn over although I have so far always been able to get the truck going and as long as I can plug it in when cold it seems to get me to work and back. I may go ahead and replace the relay. As stated I have replaced the solenoid on the starter and the ignition switch already and had O'reilly's test the starter twice and it passed both times with all values in the normal range. The test machine went dead the first time he hooked the starter up and he had to reboot it so that still makes me think that there may be an internal issue in the starter itself.

[NoRalPh]

Low Voltage wouldn't cause the relay to "stick" I don't think. The magnetic field, generated by the coil in that relay, would be weaker and less likely to hold-fast. If this happens only during a cold start (and Really cold starts, like without the benefit of being plugged-in on a frigid morning) would be when the current demands are the highest.

Bad contacts in the relay are then put to the test and is sounds like they're welding themselves together because of excessive heat (the solenoid on the starter wouldn't be able to do this if the relay had opened as it should because there wouldn't be any power available)

So, either the Ign SW is falsely holding the relay energized, OR the relay contacts are staying closed despite the SW opening the circuit to the coil and shutting down the electromagnetic field.

Next time, don't pull the Battery cable but disconnect either one of the sm wires on the relay. If it stops cranking, it's the sw (or sw circuit) if it doesn't it's the relay...

[Joe Michaels]

Thanks for the help. I will prob go ahead and replace the relay since it is relatively inexpensive. One other side note....my "service engine soon" indicator came on since I got it started this time.