Bender - 2010 JKUR

[Jdofmemi]

3 hours ago, fiend said:

Thanks for the suggestion Jerry. I haven’t tried that but I’ve thought about it. I either need to put the battery back in the Jeep or I need a second set of jumper cables to do it. 
 

I’m not sure if you saw, but I did take out the starter and bench test it.  It’s functional. 

That's part of what made me think of it. Starter works when hooked up direct. The cable in the Jeep may be a problem. 

See if you can check for a voltage drop at the starter end of the cable while trying to crank it. It should only drop a slight amount. A large drop indicates a problem. 

 

If that does not solve it, also check for voltage drop in the signal wire. 

 

Somewhere in those two you may find the problem

[Dave]

18 hours ago, Jdofmemi said:

That's part of what made me think of it. Starter works when hooked up direct. The cable in the Jeep may be a problem. 

See if you can check for a voltage drop at the starter end of the cable while trying to crank it. It should only drop a slight amount. A large drop indicates a problem. 

 

If that does not solve it, also check for voltage drop in the signal wire. 

 

Somewhere in those two you may find the problem

You could also try disconnecting the "S" terminal from the starter solenoid and run a temporary wire from there to the battery.  That bypasses the ignition switch, TIPM & starter relay but tests the starter cable.  Likewise, while that wire is off you can see if you get voltage there when you turn the key.  

 

You said when you turn the key you hear a click.  Can you tell if it is from the starter solenoid or the starter relay?

[fiend]

2 hours ago, Dave said:

You could also try disconnecting the "S" terminal from the starter solenoid and run a temporary wire from there to the battery.  That bypasses the ignition switch, TIPM & starter relay but tests the starter cable.  Likewise, while that wire is off you can see if you get voltage there when you turn the key.  

 

You said when you turn the key you hear a click.  Can you tell if it is from the starter solenoid or the starter relay?

Thanks for the suggestion. I need to mess around more with the starter, to see if it’s  a cause or a symptom. 

[Jdofmemi]

13 hours ago, Dave said:

You could also try disconnecting the "S" terminal from the starter solenoid and run a temporary wire from there to the battery.  That bypasses the ignition switch, TIPM & starter relay but tests the starter cable.  Likewise, while that wire is off you can see if you get voltage there when you turn the key.  

 

You said when you turn the key you hear a click.  Can you tell if it is from the starter solenoid or the starter relay?

Good idea Dave

[fiend]

So I don’t think the parasitic draw is at the starter.  I wired the meter in series at the ground cable and took the TIPM out of the system, leaving only the starter and the alternator wired up. The draw went from 2.5 amps to zero. This suggests to me that something wired through the TIPM is the problem. I still can’t understand why it won’t crank and whether that’s related or unrelated to the draw. 

[Dave]

Bummer if the TIPM is bad, but it sounds like your on to something if disconnecting it gets rid of the parasitic draw.  Could be a bad circuit board trace or faulty solid state component.  Have you tried disconnecting and reconnecting the multi pin connectors on the bottom of the TIPM?  Possibly a bad or dirty connection there?

 

 

10 minutes ago, fiend said:

So I don’t think the parasitic draw is at the starter.  I wired the meter in series at the ground cable and took the TIPM out of the system, leaving only the starter and the alternator wired up. The draw went from 2.5 amps to zero. This suggests to me that something wired through the TIPM is the problem. I still can’t understand why it won’t crank and whether that’s related or unrelated to the draw. 

 

[fiend]

14 minutes ago, Dave said:

Bummer if the TIPM is bad, but it sounds like your on to something if disconnecting it gets rid of the parasitic draw.  Could be a bad circuit board trace or faulty solid state component.  Have you tried disconnecting and reconnecting the multi pin connectors on the bottom of the TIPM?  Possibly a bad or dirty connection there?

 

 

 

Thats my next step. I read an old thread on one of the forums where a guy had similar symptoms.  After a bunch of trouble shooting he found that one of the wires coming out of the bottom of the TIPM had chafed away it’s insulation and possibly was intermittently shorting. 

[Nice Little Jeep]

I’ve been so busy with my build I forgot to look at other builds, sorry about that man your Jeep looks really great just got overwhelmed doing this overall on the NLJ.

[Nice Little Jeep]

Electrical problem sucks, I was so thankful that it was the tail lights that was my problem because I would’ve just threw up my hands and said fuck this if it was something else. My welder was giving me some false readings and I disconnected and I was able to dial it into my tail lights and my brake booster .

[fiend]

11 hours ago, Nice Little Jeep said:

Electrical problem sucks, I was so thankful that it was the tail lights that was my problem because I would’ve just threw up my hands and said fuck this if it was something else. My welder was giving me some false readings and I disconnected and I was able to dial it into my tail lights and my brake booster .

Yeah I am about to pull my hair out with this. 

[fiend]

Alright so after more messing around with this I’m questioning my initial conclusion that the draw is from something on the TIPM. I was seeing a 2.5 amp draw before, but that drops down to 20-30 milliamperes after a few minutes.  This is consistent with what I’ve read about these vehicles; it takes a couple of minutes for them to go to sleep.  And, 20-30 milliamperes is within acceptable spec.  So maybe my draw, if I even had one, was on the accessories system. Maybe I was just having a dying battery and no draw at all. Anyway, I’ve disconnected all the aftermarket accessories/ second battery system entirely for now as I chase down the no crank problem. On that, here is the current data:

 

The starter bench tests operative.  Putting 12.6 volts (charged battery) to the starter pole and solenoid operates the bendix and the gear spins with speed and apparent power.  I don’t detect any shorts with the starter. 

 

There are 12.6 volts at the main power line from the battery to the starter. The line is in good shape. The starter mount is grounded.  
 

There are about 11.8 volts at the line to the starter solenoid when the ignition key is turned to start.  I’m not sure why it’s not 12.6 volts. The 11.8 volts is not enough to activate the solenoid/bendix.  So I need to find a wiring diagram and figure out where the wire comes from and what might be causing the voltage drop. 

[fiend]

I removed the TIPM and was able to test a few things. With the starter relay jumped, there is zero detectable resistance between the main power pole of the TIPM and the TIPM pin that goes to the starter solenoid wire.  And, with 12.6 volts applied to the main power pole of the TIPM, and with the starter relay jumped, there are 12.6 volts at the pin. So this tells me that the TIPM is not the cause of the no crank; there’s 12.6 volts going in, and 12.6 volts coming out. Because the TIPM and the starter solenoid check fine, the problem appears to be in the wire between them.  Somewhere along the way the voltage drops from 12.6 to 11.8. 

[Crawl2Camp]

3 minutes ago, fiend said:

I removed the TIPM and was able to test a few things. With the starter relay jumped, there is zero detectable resistance between the main power pole of the TIPM and the TIPM pin that goes to the starter solenoid wire.  And, with 12.6 volts applied to the main power pole of the TIPM, and with the starter relay jumped, there are 12.6 volts at the pin. So this tells me that the TIPM is not the cause of the no crank; there’s 12.6 volts going in, and 12.6 volts coming out. Because the TIPM and the starter solenoid check fine, the problem appears to be in the wire between them.  Somewhere along the way the voltage drops from 12.6 to 11.8. 

Great detective work Greer.  I hope you get that bum wire now.

[fiend]

Thanks. But I’m sorry to say that the problem is not the wire to the starter solenoid. I just tested it from the end at the TIPM to the end at the solenoid. No resistance, no voltage drop.  So now I have no idea what to try. 

[Dave]

Well according to this diagram the starter solenoid circuit is pretty straight forward.  If the relay is good and the wire to the starter is good, then it has to be either the relay socket,  one of the connector pins/sockets or internal PCB trace/wire in the TIPM.

 

I'm not sure if you tried swapping the starter wire with one going straight to the battery and if it cranked?  

[fiend]

Well after all the messing around it turned out to be faulty technique rather than faulty equipment. In chasing down the parasitic draw, I’d removed the batteries.  Then the no crank came up.  I’d been chasing that down with a battery on the ground connected to the Jeep with jumper cables.  Well, that just isn’t a good enough connection to crank, I guess. Voltage showed good, but not enough amps. Once I had checked the fuses, relays, connections, and wires, I was stumped.  I decided to just put it all back together, dual batteries and all. Made sure the battery connections were good and tight.  Started right up, no problem.   So I guess the no crank “problem” is “fixed.” . Remains to be seen if I even had a parasitic draw to begin with, or just a dying battery.  I took out the dead one and put one in that checks good. We will see if she starts tomorrow after sitting all night.    

[Crawl2Camp]

A win is a win.  Time for a nice cold beer.

[fiend]

1 hour ago, Dave said:

Well according to this diagram the starter solenoid circuit is pretty straight forward.  If the relay is good and the wire to the starter is good, then it has to be either the relay socket,  one of the connector pins/sockets or internal PCB trace/wire in the TIPM.

 

I'm not sure if you tried swapping the starter wire with one going straight to the battery and if it cranked?  

Thanks Dave. I had various diagrams and used to try to isolate the issue.  Turns out the hardware wasn’t the problem.

[fiend]

22 minutes ago, Crawl2Camp said:

A win is a win.  Time for a nice cold beer.

Hell yes. 

[Jdofmemi]

I had a long winded post written this morning, and apparently didn't push the post button. 

 

Checked back now to find it still a draft, but you have tentatively solved Benders mystery. 

 

That it is solved now. 

 

 

 

 

 

 

[Dave]

Fingers crossed  

[fiend]

2 hours ago, Jdofmemi said:

I had a long winded post written this morning, and apparently didn't push the post button. 

 

Checked back now to find it still a draft, but you have tentatively solved Benders mystery. 

 

That it is solved now. 

 

 

 

 

 

 

I assume you were going to suggest that I was chasing my tail and should just put it all back together and see what happens. Sage advice. Too bad I didn’t see it earlier.

[Jdofmemi]

It's maddening when you put something together and it doesn't work, take it all apart, find nothing wrong with it, then put it back together for it to mysteriously start working. 

 

Glad it's working, and hopefully it stays that way. 

[fiend]

30 minutes ago, Jdofmemi said:

It's maddening when you put something together and it doesn't work, take it all apart, find nothing wrong with it, then put it back together for it to mysteriously start working. 

 

Glad it's working, and hopefully it stays that way. 

Yep. I’ve experienced that enough times that I should have stopped flailing a week ago.  Oh well. Assuming no parasitic draw, I have just a few more things to do before Bender will be ready for a trial run on a real trail. Big Bear beckons …

[AJK]

17 hours ago, fiend said:

Well after all the messing around it turned out to be faulty technique rather than faulty equipment. In chasing down the parasitic draw, I’d removed the batteries.  Then the no crank came up.  I’d been chasing that down with a battery on the ground connected to the Jeep with jumper cables.  Well, that just isn’t a good enough connection to crank, I guess. Voltage showed good, but not enough amps. Once I had checked the fuses, relays, connections, and wires, I was stumped.  I decided to just put it all back together, dual batteries and all. Made sure the battery connections were good and tight.  Started right up, no problem.   So I guess the no crank “problem” is “fixed.” . Remains to be seen if I even had a parasitic draw to begin with, or just a dying battery.  I took out the dead one and put one in that checks good. We will see if she starts tomorrow after sitting all night.    

Lol.....really? Well gald you got her starting again.