Killing multiple starter solenoids!

[O'Rattlecan]

I killed 2 starter solenoids in one day yesterday, and am going to have to replace the thing again today.

What is the usual cause of killing these solenoids other than age? Why would they be dying? Is there something wrong with the battery? Let me know where I need to check voltage, etc. I'm baffled and can't keep buying a $25 part each time I need to start it.

Ryan

 

[bowtiehatr]

where are you getting your solenoids from? i have seen brand new out of the box parts. try a different source for parts.

 

[Skandocious]

This could very well be a starter that's going bad. Mine is on it's way out and it would fail once every 4 or 5 starts-- had me thinking it was the solenoid but I figured out it was not. Couple different things you can do here...

1) Grab one of the broken solenoids and ground the backing plate, then put +12v to the smaller post at 6 o'clock. If you hear a *CLICK* sound inside the solenoid, then another *CLICK* when you break the circuit, then the switching mechanism is still working inside the solenoid. Now measure the resistance across the other 2 LARGER posts--- if you get a whacky reading then the solenoids power circuit is fried.

2) Put a multimeter across the 3 o'clock and 9 o'clock posts on the solenoid which is currently hooked up to your truck. It should read +12v, give or take about 1v. If you don't see a reading somewhere in that range then you've got a problem in your changing system/battery.

3) Next time you get a failed start, try to jump the solenoid by connecting the 3 o'clock and 9 o'clock posts with a plastic/rubber handled screw driver. This, in essence, just bypasses the switching mechanism inside the solenoid and puts +12v directly from the battery to the starter. If the engine doesn't turn over then you've probably got a bad starter. Keep in mind your engine won't START unless you've got the key in the on position (fuel pump and ignition coil have no power unless the key is on), so the engine will only TURN OVER.


As I mentioned before-- I had a condition where the truck would get a failed start every 4th or 5th start, and I thought maybe it was a bad solenoid until I jumped the posts on the starter and it didn't do anything. Then I rapped my starter with a 1/2" ratchet and it cranked right over. My starter is on the way out and it could very well be what you're problem is too.

Clarification, in case you dont know: A solenoid is just heavy duty relay. It's got an inductive circuit for the switching mechanism and a power circuit to pass the power along through the unit.

Power circuit: 12v in = 9 o'clock post, 12v out = 3 o'clock post
Inductive circuit: 12v in = 6 o'clock post, 12v out = backing plate

The backing plate on the solenoid is designed to ground directly to the body of the truck when you mount it. Might want to also make sure that you're getting a good ground at the solenoid too


Disclaimer: I'm not an electrical expert and I don't claim to be. So if anyone finds problems with my above suggestions, dont get all in a huff-- just correct me and I'll walk away with my tail between my legs

 

[O'Rattlecan]

where are you getting your solenoids from? i have seen brand new out of the box parts. try a different source for parts.

O'Reilly's.

Chris:

I'm not going to sit here and rule out a starter completely, but as my first course of action (I have to get this to work tomorrow!) I need to focus on what is killing the solenoids so when I get it started, I can RETURN home.

The starter is about 2 months old and was working fine. I pulled it and had it tested at O'Reilly's and it passed with flying colors just yesterday.

I really need to know what it is that's killing these solenoids, or at least things that can possibly do it so I can investigate.

Ryan

 

[Skandocious]

Before you can figure out what's killing the solenoids, you need to figure out WHICH part of the solenoids are failing...

If you find yourself stranded with a bad solenoid (so you think), just turn the ignition to ON and jump the larger posts on the solenoid with a screwdriver then be on your merry way

 

[bowtiehatr]

other than a bad starter or bad parts, you dont have many options for failure. if power and grounds check ok, then its either or. if the solenoid is bad you can start your truck by the solenoid and it will drive fine untill you shut it off.

also somthing else, you may not be getting a signal to your solenoid. the small terminal is the trigger wire that goes through several safety switches that could be intermitently making contact. how are you going about diagnosing the starter solenoids?

 

[O'Rattlecan]

Looks like I have 1.9-2.0 ohms of resistance across the 3 and 9 o'clock solenoid pillars. I'm making sure there's a strong charge in the battery. It's on the charger now.

I tried connecting the two larger pillars to bypass the solenoid, and all i got was 'click'. Aaaaggggghhhhh... If it is the starter... Geez. Granted, the battery was only pushing 10v because mom left the ignition on all last night. Although I have started with voltage in the 9's before.

Ryan

 

[mrfixit]

sounds like the starter for sure.
A bad starter, be it because of a short in the field or even just worn brushes, creates extremely high resistance. a standard solenoid is only rated at, like, 25 amps. They make stronger ones, but for cryin' out loud, this is a 5.8, not a diesel
Starters get old. they die. ESPECIALLY if they were started several times with the bad solenoids. the lower the juice going to the starter, the more wear on the starter.

 

[bowtiehatr]

ryan, you may have a bad solenoid, but on the starter. i know ford started doing the 2 solenoid deal in mid 90's and you may have one like this.

 

[CaFordDude]

so when I get it started, I can RETURN home.

You sure THEY want that? Maybe your family is breaking your truck...

 

[O'Rattlecan]

heh...

I got a new battery and have it charging. I needed a new one anyway and want to take any weak spots of out the equation that I can.

Ryan

 

[mrfixit]

... want to take any weak spots of out the equation that I can.

Ryan

So, you're going to let someone ELSE fix it, right?

 

[O'Rattlecan]

Well that's why I throw parts at it...

Ryan

 

[surewhynot]

Also old battery cables can cause high resistance and burn up solenoids.

 

[Skandocious]

I remembered something last night when I was laying in bed, Ryan...

Make sure that when you're measuring the resistance across the 3 and 9 o'clock posts, that you've got +12v going to the 6 o'clock post and ground to the backing plate-- or else the circuit will be open between the 6 and 9, and you won't get an accurate reading.

 

[O'Rattlecan]

Tony, I think I'm actually going to invest in some battery cables. The ones I had were getting unusually hot under load.

Ryan

 

[NeXtras]

Tony, I think I'm actually going to invest in some battery cables. The ones I had were getting unusually hot under load.

Ryan

short circuit some where?

 

[andym]

If the starter was tested OK, and the truck won't start when you short the posts on the solenoid, then it pretty much has to be the cables. I replaced the cables in my Bronco and my truck and it made a big difference in how easy it was to start.