Starter / Transmission Issue?

[remac226]

I have a 91 model 80. I have been having a problem with the starter since I got it. Seems like a standard starter solenoid problem because when I tap it with my maglight it will usually start working. I was going to pull it and replace it this weekend but I had a weird problem last night. It would not start and I tapped it a few times and nothing. Went through this “procedure” several times with no results so I shifted the truck from park to drive and back to park and it cranked up. I do know there is some electronic part that prevents the truck from starting in gear. My D light on the instrument cluster flickers sometimes when I am driving and if I put slight pressure on the shift lever then it stays on. Could the light and the no start be related? Could it be that when I tap on the starter (since it is connected to the engine / bell housing) that I am vibrating the electrical switch and causing it to start and it really has nothing to do with the starter solenoid? I am going to try the shifter thing first next time it does it but was wondering if anyone had any suggestions or if the light issue was something I could clean and try before I buy a starter.

Thanks!

 

[bhmmapping]

The starter circuit goes through the neutral safety switch. I chased a starter problem for months and even swapped in a new Toyota reman with no improvement. Eventually I figured out that there are two circuits going to the starter - one large wire directly from the battery supplies power for turning over, and one logic circuit that activates the solenoid. The logic side goes through the ignition switch and neutral safety switch. I, and a few other mud members, wired in a new relay on the logic side. In my case there was enough current to trigger the new solenoid which only requires minimal current, but not the solenoid on the starter itself.

 

[bhmmapping]

https://forum.ih8mud.com/80-series-tech/328659-sleuths-needed-intermittent-start-devil-me-again.html

 

[jonheld]

You most likely have 2 issues to fight.
1. replace the starter contacts and plunger. This will eliminate the need for a Mag light start switch.

2. The contacts in the Neutral Start Switch (NSS) can become worn and intermittent especially if introduced to water. The NSS is a pie shaped part on the left side of the transmission housing. The associated connectors live on the right side of the bell housing by the firewall. The smaller 2 conductor circular connector is the actual contacts for the NSS. This can be jumped on the harness side to diagnose, but the starter will be able to crank in all gears so be careful.
Inside the NSS are solid copper conductors with a spring loaded copper wiper arm. Typically the teeny weenie springs behind the wiper arm fail and it doesn't make good contact. I purchased a used NSS from a parts dealer and rebuilt mine. Polished up the copper detail and packed it with grease. That was about 10 years ago.

 

[rhyary]

Is this the same on the 1996-7 trucks?

 

[jonheld]

I don't know if they are interchangeable. The later trucks use the NSS to talk to the ECU to let it know what gear you're in. The older trucks just use it to throw dash tallies.

 

[remac226]

Jonheld - It did it at lunch and shifted through the gears back to park and it fired right up. Do you have any photos of what you are talking about or is there a thread that walks you through the repair you describe. We are talking about a fix for a 91 model right?

 

[jonheld]

It's pretty easy once you open it up. IIRC I did it without disconnecting the connectors. I just let it hang right on the side of the transmission. I would have a replacement at the ready.

 

[remac226]

I have read all the threads about my issue. My truck is a 91 model. On the dirvers side of my transmission I found a 1/3 pie shaped contraption my maual refers to as the neutral start switch. I did not remove it yesterday and clean it because I was looking for this plug (below) on the passenger side of the truck. Does my 91 not have the plug pictured below? What and where exactly is my neutral start switch on a 91. I appreciate the help!

 

[corsair23]

Does my 91 not have the plug pictured below? What and where exactly is my neutral start switch on a 91. I appreciate the help!

Pretty sure that picture of the NSS on the PS of the vehicle only applies to the 93+ FZJ80s - the picture looks pretty dang familiar . I've never seen a picture of the FJ80 version but reading above your NSS switch will be on the other side and you apparently found that yesterday based on what your manual was telling you

Someday we'll have to ask Romer or Ige to update the FAQ and put a note by those pictures that they ONLY apply to the FZJ80

 

[Eicca]

Is the neutral start switch also what shuts off the accessory and other circuits during cranking or is that just the juice getting sucked out of them?

 

[bhmmapping]

it sounds like you found it the first time.

 

[remac226]

I appreciate it! Gonna remove and clean it all this wekend. Being that there were changes between the 91-92 and 93+ sometimes it is hard to tell which years are being talked about on the threads. So am I right in saying that on my 91 the "pie" switch on the 91 still kills the starter if it is in gear or not?

Yes I hijacked the picture from another thread. Had too. Hope noone minds.

Thanks!

 

[jonheld]

What and where exactly is my neutral start switch on a 91.

From post #4. I have to ask what part of this is unclear?
"The NSS is a pie shaped part on the left side of the transmission housing. The associated connectors live on the right side of the bell housing by the firewall."

 

[jonheld]

Is the neutral start switch also what shuts off the accessory and other circuits during cranking or is that just the juice getting sucked out of them?

The ECU shuts stuff down while cranking. The starter logic hits the ECU in 3 different places.

 

[VanGo]

Jon Held-

Lots of good information!

 

[remac226]

Yes John it is alot of good information. The confusion came in looking for pictures of the connectors on the forum and finding the one I posted which lives on the right side of the transmission. Not being an expert mechanic and never having delt with this issue on any vehicle it can be a little confusing. I will look for the connector you mentioned again.

Thanks

 

[jonheld]

OK, I see where the confusion came from. The NSS itself lives on the left side of the transmission housing and looks almost identical to the one in the picture, but there is no connector on the NSS itself. The wire harness that attaches to the NSS runs up and over the transmission and terminates to 2 connectors on the right side of the bellhousing by the firewall. One smaller round connector with 2 terminals is the contacts for the NSS. The other larger rectangular connector runs the dash tally lamps to let you know what gear you're in.

Clear as mud?

 

[corsair23]

Yes I hijacked the picture from another thread. Had too. Hope noone minds.

Heck no I don't think anyone minds...I've just seen it pop up quite a bit lately and thinking it would be nice to have a note on the picture that it applies FZJ80s vs. FJ80 to reduce the confusion

 

[96r50]

Heck no I don't think anyone minds...I've just seen it pop up quite a bit lately and thinking it would be nice to have a note on the picture that it applies FZJ80s vs. FJ80 to reduce the confusion

Actually, that photo only applies to the A343F transmission in the OBDII trucks (95-97). The A440F (91-92) and A442F (93-94) NSS is on the driver's side as Jon indicated.