Starter Problems: Help With Diagrams

[Stranger]

I went to start the Deuce this evening but had no luck. It started fine yesterday. (The only difference between today and yesterday was a goodly amount of rain.)

I pushed the start button with the fuel off to make sure it wasn't hydrolocked. The engine turned over for a couple seconds, but then it stopped. It was like I had taken my finger off the start button, but it was still depressed. Pushing the start button did nothing. I decided to go ahead and try it with the fuel on but the start button still did nothing.

The start button works. (checked for continuity while pushed and it worked fine.)
The start button has power (I removed the connector and check the voltage between the leads: 24V)
If I bridge the two large bolts on the end of the solenoid I get sparks and the starter spins. However, it just spins freely (doesn't engage the flywheel?).

I came here to see what else I could find and came across this set of things to check on. However, I have no clue where "wire 2 of the bendix" is located. I have the wiring diagram that was posted, but I can't tell wire 2 from the man in the moon. Is that one of the bolts on the end of the selenoid?

1. check for 24V constant on wire 2 of the bendix. Tests the lead from the battery.2. check for 24 constant on wire 14 at the start relay. Tests the smaller lead from the bendix to the relay.
3. push the button and check for 24V at wire 214 on the start relay and at the other end at the bendix. Tests the relay contacts.
4. push the button and check for zero volts at terminal 4 on the bendix (GND) Tests that the bendix ground path is good.
5. check with the ohm meter between terminals 1 to 4 of the bendix, this is the actuating coil and should be less than 1 ohm. Tests the bendix coil.
6. push the button and check for 24V at terminal 3 of the bendix. this is the terminal that feeds 24 volts DC to the starter motor. It will have a big, short strap as the wire, usually. Tests the benxix contact. It can be burnt and the bendix will engage but not turn the starter on.

We were supposed to use this truck in tomorrow's parade.

 

[whatadeuce]

Hello STRANGER, And here is a diagnostic you can try: With batteries up, and MASTER SWITCH in the OFF position, connect voltmeter negative lead to ground, and positive lead to MAGNETIC STARTER RELAY terminal "D". Terminal D is the terminal that conductor # 74R is connected to, and which comes from the outlet oof the MASTER SWITCH ( which is now OFF) Now turn on the MASTER SWITCH. Do you have 24 VDC at your meter? If you do, then the MAGNETIC START RELAY SHOULD energize,the starter solenoid, and then the starter motor will engage.

If the magnetic starter relay does not energize, the perfoRm the following: use jumper wire and jump magnetic starter relay terminals A and B. As you ,may not be able to identify these two terminals, they are the ones using heavier size conductors, and you also can trace them with your diagram, TO BE SURE itch ones they are. If you jump the wrong one you will damage the relay. When you jump these terminals you are energizing the STARTER SOLONOID,and the starter motor shouild turn and crank. If it does not

connect your meter to ground, and the hot terminal on the starter motor itself. Confirming that the solenoid is powered, but the starter motor is or is not getting power according to your meter you will isolate which of these devices is at fault. Keep us all posted

 

[Stranger]

I have an update. After getting some sleep I had a clear head and thought I might as well try jumping it. Its easy and I had nothing to lose. (When I picked her up we had to jumper her, but then in the following days I didn't.)

I connected up and she turned over the first try! After letting her idle for a hour I shut her off and she started right back up again.

Will weak batteries cause a problem such as this one?

I pulled a bone headed move and didn't try try to start before I jumped, so I have no idea if it is an issue that "fixed itself" or something to do with weak batteries.

 

[Stranger]

whatadeuce, you are awesome! Thank you! In the next week I will go through and check all those wires and connections. I would hate to be on the road, stopped for fuel somewhere and discover that it is a loose connection.

 

[whatadeuce]

Thats right STRANGER, and when you check your connections for tightness, look to see if any of the wires are frayed, peeling, or otherwise showing evidence that thy are overheating. If you do any re connecting, make sure you brush clean the terminal posts where the wires are connecting to, and also wire clean the connectors themselves until they are bright. bright .

 

[whatadeuce]

As far as batteries are concerned, you can test them for capacity. If you dont have the tester, you can bring them into a service place that does, and have them tested. Confirm if they re weak or not. If they are, replace them. WHATADEUCE

 

[Stranger]

Thats right STRANGER, and when you check your connections for tightness, look to see if any of the wires are frayed, peeling, or otherwise showing evidence that thy are overheating. If you do any re connecting, make sure you brush clean the terminal posts where the wires are connecting to, and also wire clean the connectors themselves until they are bright. bright .

Pretty much all of them are frayed and peeling. I think an entire new front end wiring harness is in my near future. This is a 1970 AM General with the original engine. I don't see evidence that it ever went through an overhaul.

 

[whatadeuce]

If you want a new harness, it's best to plan for it in advance. Read the diagram so you are familiar with the harness. Also m,aake sure your new harness is numbered like the original. Kepp us all posted on this...WHATADEUCE

 

[Stranger]

If you want a new harness, it's best to plan for it in advance. Read the diagram so you are familiar with the harness. Also m,aake sure your new harness is numbered like the original. Kepp us all posted on this...WHATADEUCE

Making sure it is numbered like the original may be difficult. The little tags aren't present on most of the wires and the ones that are present are illegible.

Roger on the updates.

 

[whatadeuce]

Whoever you would but the harness from will ( must) give you a harness that is numbered. Your diagram will tell you what wire goers where. Do you need a diagram?

 

[Stranger]

Whoever you would but the harness from will ( must) give you a harness that is numbered. Your diagram will tell you what wire goers where. Do you need a diagram?

Oh, yes. I thought you meant my current set would need to be numbered. (I don't know why I thought that. It doesn't make any sense.

I think I might have the diagram. Is there a TM number I should look for?

 

[Stranger]

Update!

After the parade I went over to a local place and had them test the batteries. Both were showing around 250 CCA, so I think replacement are in order. He also mentioned that I need to check the alternator, however, I couldn't figure out how to do that on the fly, so I am back here searching for how to test alternator output.

 

[Mayapple]

Following...

 

[Stranger]

Update #2.

Back to no power to the starter again. Unfortunately, this time, I can't get it to jump start either.

I got replacement batteries. But after I swapped them out I couldn't get it started. All battery connections appear to be good. I am showing the proper voltage across each battery (12.8V) and in series (25.4V).

I am starting to suspect that my miracle jump start fix was nothing more than loose/jiggling wires making a connection. When I replaced the batteries I giggled them loose again.

 

[whatadeuce]

Hello Stranger, Not to worry. There is a published diagnostic for just this problem. Plkease turn to TM-9-2320-209-20-2-1, page 25-2. ( this is page 244 on your computer scroll page indicator. ) This is the section entitled STARTER MOTOR WILL NOT CRANK Does your machine have a foot switch or a dash mounted push switch, because the troubleshooting procedure addresses both, as you will notice. If yours is a dash mount switch, proceed to page 25-11 (260) And here on page 260 begins the detailed troubleshooting technique for the both the starting components, and the connecting wires for these components, The description continues to page 268. Be patient and familiarize yourself with the LOGIC of this procedure before you do the tests. You cannot fail because this procedure was written by General Douglass Mc Arthur himself!

 

[Stranger]

Hello Stranger, Not to worry. There is a published diagnostic for just this problem. Plkease turn to TM-9-2320-209-20-2-1, page 25-2. ( this is page 244 on your computer scroll page indicator. ) This is the section entitled STARTER MOTOR WILL NOT CRANK Does your machine have a foot switch or a dash mounted push switch, because the troubleshooting procedure addresses both, as you will notice. If yours is a dash mount switch, proceed to page 25-11 (260) And here on page 260 begins the detailed troubleshooting technique for the both the starting components, and the connecting wires for these components, The description continues to page 268. Be patient and familiarize yourself with the LOGIC of this procedure before you do the tests. You cannot fail because this procedure was written by General Douglass Mc Arthur himself!

dueceman, you are awesome!

I had been looking for that exact TM but my searchfoo was weak and I couldn't find it for the life of me!

Unfortunately, I have the worst kind of starter problem. An intermittent one! I was able to get it started again without any effort whatsoever! I walked through the troubleshooting procedure and the system checked out at every turn. (The only issues I encountered were a couple loose wires that didn't affect voltage or connectivity).

So, I shut up down. I was able to start it back up again. I shut it off again. But, the next time it wouldn't start! My wife was watching while I pressed the start button and nothing happened. So, I just held the button there for a few extra seconds and it suddenly started. Its like a ghost in the machine.

My thought is that perhaps my starter relay is going bad. Perhaps it is taking an extraordinarily long time for the capacitor to energize?

 

[whatadeuce]

CAPAc ITORS? You can still pinpoint the intermittent problem by going through the test procedure, but in reverse, where tou connect tour voltmeter to the starter motor leads, then repeatedly push the start button. Each time you Push the start button, tou will observe if the start motor will crank.if it does sa for 5 times, then move rr on next toy leads to the starter solonoid, But. If it happens that when you push the start button. AND YOUR METER READS VOLTAGE, UT THE MOTOR DOES NOT CRANK. TH=N TOU HAVE PROVES A DEFECTIVE MOTOR...you do this type of test for ea h component, And conductor....you will catcg the culprit. ..

 

[Stranger]

Sounds good. I will get back into this evening.

I have to say that it is disconcerting to be under/around the engine when it turns over. Gets your blood pumping quick!

 

[whatadeuce]

Earplugs!

 

[Stranger]

Things are going from intermittent to just plain weird! My deuce is starting when I turn the accessory switch on WITHOUT me pushing the start button.

So, here is what happened... I started up the deuce normally and had an odd issue with the voltage gauge. The engine was running but the voltage was showing really low (down in the yellow). Then there was an odd sound (like the starter engaging) and the voltage shot up where it was supposed to be.

I drove around for twenty minutes. During my drive I had no issues and the voltage was where it was supposed to be.

After parking I shut down the engine. On a whim I tried to start it again... no dice. The button would not energize the starter. I was sitting in the cab alone cursing my bad luck, when all of the sudden.... IT STARTED ON ITS OWN! I wasn't pushing the start button! It just turned over and started running all by itself. I turned off the accessory switch and pulled the engine stop. It shut down. I pushed the engine stop back in and flipped the accessory switch back on. It started again without me pushing the start button. Then I noticed that odd sound again, like the starter was engaging. It stopped when I turned the accessory switch back off.

Running a voltmeter across the batteries shows I am down at 24.5 V with the engine running. So, I either have a bad connection somewhere or I have a bad alternator.

The video shows what was happening when I had one of my son's turning the accessory switch on and off. It makes the "bad noise" (starter engaging) when the accessory switch is on and then stops when the switch gets turned off.

https://youtu.be/p22KwygZ1hA

Any thoughts?