I have a Galion 118 grader with a Detroit Diesel 4-71. Never had a problem starting it until now. The starter solenoid won't pull in. I've charged the battery, cleaned all the connections, checked the wires and nothing. The coil of the solenoid isn't open or grounded. I disconnected the solenoid ground and connected a DVM from the solenoid coil ground tab and a good ground. I get 9.33 VDC when I energize the solenoid. With the battery voltage at 12.65, that is a voltage drop of 3.32 VDC. Can't find any test specs on the solenoid. I got 3 jobs waiting and need this thing running. Any Detroit mech's out there that can help me? Thanks.
Did you happen to ohm out the solenoid ground? Not sure what starter you have, but some have a little strap to the starter body, some have a wire. My opinion is if you're getting full voltage to the solenoid, and the ground is good, you're going to need a solenoid. Or, at the very least you're going to have to pull the starter and make sure the starter drive didn't freeze to the motor shaft.
If it has ground and power your solenoid needs to come off All we need to test is 12 volts to the start terminal and a ground a very common way to ensure that is a screwdriver from the start terminal to the battery terminal I think you will end up pulling the starter and bringing for a rebuild and you will be back to work
That measurement doesn't make any sense to me, I can't tell what it says about the coil. Take the voltage measurements again with the ground wire hooked up. One lead on the negative battery terminal, and one lead first on the hot side of the solenoid coil, then another measurement on the ground side of the coil. My guess is the hot side won't show any voltage, because it should have shown full voltage with the ground coil disconnected. If you can measure the ohms of the coil, it should certainly be less than 10, most likely it will be either be high and an open circuit, or too low to read on a cheap meter, which is good.
If you have a voltage drop with no load on the coil, I suspect it's open. Modern meters only need nanoamperes to measure voltage. Measure it on ohms as suggested above and you will probably see thousands, instead of tens or less.
Exactly what I was thinking. ANY cheap meter can read the voltage close enough for this, reading low ohms is tougher, but it will be on or the other. You're not going to come back and say " is 15.2 ohms OK or not?"
It ohmed at 0.4 ohms. That's without the plunger in it. I know that a coil of wire (inductor) shows a much lower ohm reading than one with a core (which the plunger would act as when it is fully in the center of the winding) in it. Believe it or not, I'm 54 and have worked on vehicles and engines my whole life and never had a bad solenoid on anything. So I have no past experience troubleshooting one.
I got a voltage drop of 3.25. If I divide the 0.4 ohm winding resistance into that, I get 8.125 amps of current. That seems like it should be enough. Oh and "Yes" I checked the "Bendix" and it isn't stuck. Slides the starter gear in and out very smoothly.
That's good, the .4 ohms. I don't think you have a bad solenoid. I think you're not getting full voltage to the coil when you try to start it.
NO, NO, just NO. That's not the way it works. If the ground wasn't connected, and there was ANY continuity, then you should have had the exact battery voltage on the ground side of the coil.
Don't know what you got there, but neither reading makes sense. .4 ohms is damn near a dead short, at 12 volts you would be pulling 30 amps... maybe...
I'd like to go to the basics on this. Any chance a a nice clear picture of the terminals on the solenoid? One picture that shows the complete starter and one that is a nice vew of the wire end of the solenoid would tell volumes! Then it might be easy for someone to give an easy suggestion on how to test this starter to know where the problem is located. Most likely a standard 40MT Delco. If you know exactly were to hook a remote starter button to it you could eliminate all the wiring to the starter as a cause of the problem. I'm assuming this unit does not have a Pre-Lube system on it, that would muddy the problem a bit.
A cheap meter won't read low ohms accurately, .4 just means there's continuity of some sort. That's what I'm hoping?
I use a Fluke DVM so no it isn't a cheap meter. It actually ohmed out at 0.398. 0.4 was just rounding it up by 2 milliohms.
Hit it with a Ballpean hammer. Work every time 4 us back in the 70's ;P True Story