Starting problem

[pdstout]

Guys I have a problem starting my Duce. when I turn the switches on and press the starter button, smetimes it will do nothing then it will make a loud clunk. It does this several times as I puch the starter button. Finally it will turn over and start up. I have to push the button several times. Could the battery be getting low? Is something loose? It started perfect the first few times. Now it does this. Any help would be great!
Thanks, P. Stout

 

[AceHigh]

Can you get a voltage reading before and during cranking? Are all the battery terminals clean and tight?

 

[mahdey]

sounds like the solenoid is going bad on the starter.

 

[scrapman]

Basic checks 1st. Do you have good connections,batteries,starter, grounds? Do you have a volt meter & hydrometer? Both are cheap to get & easy to use. Remove the short cable that connects your batteries together. Check the water level and add as needed. Check each battery for voltage you should get 12+ volts. Charge each battery seperately with your 12 volt charger & check the gravity of each cell with the hydrometer, the scale on the tool will guide you. At this point if everything checks good & the problem persists, starter & solenoid rebuild or replacement is inline.

 

[Speddmon]

Mine seemed to do the same thing the first few times I started it. I'll admit, that my problem was operator error. It probably isn't the same problem you are having, but try hitting the starter button with the palm of you hand. You need to press firmly on the button, not hard enough to break it, but jab your palm into it pretty firmly and hold pretty good pressure on it till it starts.

It's just the nature of DC current, it arcs a lot more than AC, therefore the contacts inside of the switch over time will develop some corrosion over them and will not allow the current to pass. I'm pretty new to the deuce myself, but not electricity. I've seen this many many times on DC equipment at work. It will often look like another problem down the line from the button, but give it a try...it's easier than a lot of troubleshooting and cheaper than a starter rebuild.

 

[cranetruck]

Speddmon could very well be right, there is no spark suppression on the starter relay, so erosion of the start switch contacts is to be expected. Prevent it by adding a diode as shown below...

 

[Speddmon]

That's a good idea cranetruck, basically it's a poor mans MOV (arc suppressor).

Edit: for those who really need to know, an MOV is a Metal Oxide Varistor, typically you see them "paralleled" with a coil to suppress the arc created by the collapsing magnetic field when the power is taken away from the coil. Usually they have a resistor in series with the diode as well.

 

[Speddmon]

Any update on this? I'm curious as to what you found if anything. I hate open ended threads....lol

 

[pdstout]

I checked the batteries. All of the fittings looked ok and tight. I can press the starter button and sometimes it will fire up and sometimes nothing. I just keep pressing it till it starts. It does not seem to be draging down the starter. I think it may be in the switch.
P. Stout

 

[dabtl]

My second deuce would start sometimes and not others. Mostly when it had been driven some and shut down, it would not start again for a long period.

I replaced the starter relay, it had a stripped nut which would not tighten further but was fairly tight, and it seems cured. You may want to check that out as well.

 

[dabtl]

Speddmon could very well be right, there is no spark suppression on the starter relay, so erosion of the start switch contacts is to be expected. Prevent it by adding a diode as shown below...

Bjorn, you are one of the great assets of Steel Soldiers. I read everyone of your posts. As a result, I can now trouble shoot most of the electrical problems I run into. This one is new, and I will mark it on my computer for sure.

Took about 15 minutes to fix the turn signals, again.

 

[wildbill]

I was having a starter problem with my 1966 Kaiser/Duece and it was the starter relay. After calling a vendor in Ogden, Utah, I was told that the
starter relay was a redundant system and that the new trucks do not have them. They said I could take off the old one and wire my starter button wire directly to my starter and It would work. And that I could take the old relay and throw it away. I did this and it works great. That was after I could not find a replacement relay and reading in this forum to buy and replace my relay. I guess we learn something new everyday.

Wild Bill/ Wyoming

 

[dabtl]

I found my relay on eBay. It was fairly cheap, but I have not seen one since.

$89 at TNJ Murray.

 

[gimpyrobb]

WOW, all that current through the dash switch? Did I read that right?

 

[Speddmon]

Gimpy,
Just the current to pull in the starter solenoid. The relay would actually be redundant in this situation. The solenoids don't pull much current, that's why they are there. The stitch to handle full starting current would be huge.

Edit, button sends current to the relay, relay sends current to the solenoid (fancy word for a relay), solenoid sends current to the starter.

 

[cranetruck]

Thanks dabtl for the kind words....wildbill, the solenoid on the starter motor may "draw" as much as 60 amps....the starter relay is selected to handle that and the start switch need only handle the coil current for the start relay, which may be in the order of 1 amp or so. You would not want to run #8 wires to the back of the dash and the switch that could handle 60+ amps would be a ducie....with a lifespan of 20 years...

 

[Speddmon]

cranetruck, as usual you are correct about the current draw of the solenoid. However, Once the solenoid pulls the pinion gear into the ring gear of the flywheel and closes the main contacts of the switch built into the solenoid, that current draw is greatly reduced. It's very similar the to the inrush experienced in AC motors when starting. Once the plunger is fully engaged, the current required to "hold" it in place is much less than the current that was required to "pull" it in.

Now there are several different designs of starters and solenoids out there, and I do not profess to know which one the deuce uses, but after the momentary inrush of current I would imagine that the holding current would drop to somewhere around maybe 8 to 12 amps give or take. My truck starts very quickly so it's harder to measure, but after I get back from my trip out of town, I'll hook up a few meters and leave the fuel stopper rod pulled out so it doesn't start and will let me crank it a little while. and run some tests and find out for sure.

 

[cranetruck]

The deuce starter has two coils, one pull-in and one holding, but you still need to design with the pull-in in mind and the spec sheet actually calls out a max of 70 amps peak IIRC and the deuce starter relay is rated at 50 amps.

Checked it and the max permitted in the spec is 81 amps worst case conditions...

 

[dabtl]

OK, I give up following this stuff. I should have majored in electronics.

For me, replacing the starter relay was simple and it seemed to work. Wiring around it is more complex than I can handle.

Will someone show me the door so I can go home?

 

[Speddmon]

First off, sorry dabtl, this is getting way more technical than the poster probably though it ever would. I'm not advocating removing the starter relay to anybody, that relay may well be what is causing the problem being discussed.

The deuce starter has two coils, one pull-in and one holding, but you still need to design with the pull-in in mind and the spec sheet actually calls out a max of 70 amps peak IIRC and the deuce starter relay is rated at 50 amps.

Thanks for that info about the starter. I was assuming that was the solenoid configuration used, but I wasn't sure. Yes, you are right again about needing to design with the pull in current in mind, but going back to the bit about the starter relay bypass, it would work just fine without the relay, but it would definitely shorten the buttons effective lifespan. The only conceivable time that the wire size would cause an issue would be if the plunger on the solenoid actually became stuck and would not pull in, simply because the higher current is there only for a matter of milliseconds under normal operation. Please know, I'm not arguing any points with you, I think the information you are providing is spot on. I'm simply saying that bypassing the relay would have little noticeable affect on the operations of the button or wiring, but that also makes what I said earlier about using a firm, crisp depression of the button all that much more important.

If you had the button on a test bench hooked up to a starter, when the button is depressed, even with the relay in place and operational for just the split second before the contacts of that button were fully closed; and again in the split second after the button was released, you would see a small arc between the contacts. This arc would be greater if the button was bypassing the starter relay because of the higher current draw, it's just the nature of DC current. It arcs a lot more than AC does. That arcing causes corrosion on the button contacts and causes them to not be as conductive as they should be. In an industrial setting we use 2 sets of contacts in series with each other for anything dealing with DC just to help break that arc as soon as possible.