Help with STARTER won't FIRE UP!!!!

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Jul 25, 2009
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Hello everyone, I recently had my fj80 (1991) parked for a month or so because I was using my other vehicle to commute, recently I tried to start it and it wouldn't even click so I took down the starter and rebuilt it.

When I took it off I ran it straight from the battery and it was stuck so like I mentioned before I rebuilt it and it runs strong. So a long story short I went ahead and installed it and it wouldn't even click so I started it by shorting it out (ignition signal and positive from starter) directly and it fired right up but it seems the other cable that goes to the starter is not sending a signal so it is not firing through the ignition switch.

I haven't gotten a chance to check it with a multimeter and see if it is sending a voltage or not. I checked the fuses and everything is fine so I wonder if anyone knows through where that cable is routed through or if someone has had experience with something like this before.

Battery and everything else is fine as it will start by shorting the connector and main 12v source.

I am thankful and I hope you can help.

Gio.
 
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Thanks, the fusible links are A OK, let me do a search for the neutral safety switch and see if that is the culprit. I kept thinking about it and it could also just be the ignition switch. I will tear it out tomorrow and test it out.

Once again thank you.
 
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Here are some news of my findings. I took the trim pieces off to get to the ignition switch, I pulled it out and checked it and it does eveyrhting it is supposed to do. It does send the signal to the right wire and I hear a relay click but it doesn't fire up. I checked the neutral switch and it is working fine as this only operates a solenoid that goes by the key cylinder that prevents you from turning the key further from on so you don't start it while it is in gear, that works too.

So I am baffled, I am going to end up putting a push button start, do any of you guys know what relays control the ignition (starter signal)?, thank you in advance.
 
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This is a very similar thread to yours.
1991 FJ80 3FE not starting (or clicking, or cranking)

As I posted, the starter circuit is one of the simplest ones on these trucks. No hidden relays, just simple direct connections.
Starter logic side is battery/fusible link AM1/main fuse AM1/ignition switch/neutral start switch/starter solenoid coil.
Starter load side is a direct connection from the positive battery terminal to the starter solenoid.

You wrote, "I checked the neutral switch and it is working fine as this only operates a solenoid that goes by the key cylinder"
That is partially correct. The starter logic passes through the NSS and there is a separate connector for it. The NSS also runs the logic for the dash tally lamps for the transmission.

I would check the logic side of the starter with a meter when turning the key to the START position and see if you are getting +12 to fire the solenoid. If not, work backwards from there.
 
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Thanks for the info. I will crawl under it a bit latter today and give it a shot. I'll have someone turn the key and see what voltage it reads.

Just to make sure the order is:

1. Battery (Checked)
2. Fusible link AM1 (Checked)
3. Main Fuse inside the cab? (I've checked fuses and relays)
4. Ignition switch does send a voltage signal bout out of the initial 12.3 or so that come in only about 9.8v go out, is this normal?, when I turn the switch to the start position the voltage drops but the battery is charged and in good order. I even tried a battery from another truck and it does the same deal.


HOW DO I truly check the nss to make sure the 12v are not making it out but it is receiving them?, I think in my case 1991 fj80 there is no connector on the NSS and therefore no true way of checking is there?


Could the starter be the culprit?, before making any assumptions I will check the voltage at the logic side of the starter when I turn the key. I will need the wife to help out.

I am posting some pictures of the switch to see if someone can help me identify a little white box that is near the key that is part of the switch.

Thanks.
 
Last edited:
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This is the solenoid that prevents you starting your truck when it is in gear, it works fine, receives voltage and pushes up when you put it in gear preventing the ability of the ignition to turn to the start position.
 
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That is the key interlock solenoid, not the NSS. The neutral start switch is mounted on left side of the transmission. It has a harness that breaks out into 2 connectors on the right side of the firewall above the bellhousing. A rectangular multi-pin connector runs the dash tally lamps and the 2 pin circular connector is the actual neutral start switch. THis is the one that the starter logic goes through.
 
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This is the solenoid that prevents you starting your truck when it is in gear, it works fine, receives voltage and pushes up when you put it in gear preventing the ability of the ignition to turn to the start position.
That is not how this device works. Its only function is to prevent you from removing the key unless the transmission is in PARK. You can always turn the key to the START position regardless of what gear you're in. The NSS cuts the starter logic in all other gears except PARK and NEUTRAL.
 
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You are 100% correct, I did see the NSS when I took out the starter to rebuild it but I haven't disconnected it since I can't find the round plugs yet so I can check the voltage coming from the switch. What do you think about the voltage drop form 12 to 9.7?, is this normal even if it is not turning the starter?
 
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Some news, I had help from the wife and checked the logic wire that goes to the starter for power and it receives 12.2v but it is not enough amperage to spin the starter. I started it directly from the battery wire to make sure the battery was still good. Could this be a bad connection or corroded connector on the way?, maybe the nss connectors are corroded but I will have to look for them tomorrow.

Thank you again for all your help.
 
Joined
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Verify the NSS operation is correct. Still a possibility there.

Here are some thoughts on the ignition switch, since you are seeing significant voltage drop.
Some Thoughts on Starting System Failure: Ignition Switch & Solenoid

There's one pic there, but a bunch more on page 2 in the ignition switch thread linked from my post:
Ignition switch replacement procedure.

Some actually wire around the ignition switch and install a start button.:hillbilly: OEM was good enough for almost 2 decades of service, so I went that route. I think the switches are very similar between 91 and 97 in pics, but wouldn't surprise me that yours may have a different part number. If you order, verify that with your vendor.

It didn't solve my nonstarting issue, but did help. You've already done the other part, so this might be the fix if the NSS isn't in Fail mode.
 
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Thank you greentruck, it is very useful info. I will open the switch and give it a clean to see if that solves the voltage drop at the switch but the odd thing is that the voltage at the starter logic wire is 12v when you open the switch to start position but not enough juice to get it started.

I will check the switch and the nss. If all this fails then I will wire a relay and install a start button.

I will open it up tomorrow if I get a chance and post up a few lines with a pic or two.

Thanks.
 
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If you do, keep in mind my cautions about the springs, etc inside the switch body when you open it as you don't want to lose your balls...:rimshot:

As my pics show, there can be both a blackening along the sweep of the contacts on the discs that rotate to contact and some actual distortion/pitting of the contact plates. And your truck is 6 years older than ours. Cleaning it and reassembly should buy you some time with some luck. The part seems to keep going, but performance drops off. Eventually you get to no go some of the time.

If you have the $100 and you've ruled out other things, then you might want to hold off the tear down, get the part and then do the deed. If you slow and old like me, maybe a 3 hour job. It goes back together faster than it comes apart -- assuming you don't lose the balls, springs, etc. Take it apart gently over a plastic catch basin in an area where you can hunt stuff down if it takes a leap. Once you figure it out, it's easy to reassemble if you haven't lost anything.
 
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Thank you, I will order a new switch and give the old one a look inside. What I am going to do tomorrow is wire a relay that goes directly from the starter switch to activate the relay and the power source from the battery with a fuse that way it pulls nice and strong and I don't have to use a push button start. The switch will activate the relay.


Once again thank you for all of your help and I'll keep you posted.

I am going to disconnect the logic wire from the starter also and test the voltage at the switch again, if there is a large voltage drop maybe something is grounded.
 
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So I have some good news. I decided to give it another go, I got to the NSS and took it apart but it was kind of a nightmare since I had to take it apart almost in place as I couldn't find the connectors. I think the truck some work done at some point and when the put the harnesses back, they zip tied everything really tight. I opened it right there and then the two springs and contacts fell on me and I couldn't find them.

I ended up finding the contacts and one spring and I used a spring from an ac valve that I took apart, to make the story short the NSS was full of old grease and the contacts were quite dirty so I cleaned all the contacts, greased it up a bit and voala it started but at the second try everything went dead I mean no power to anything. So I went to the battery and the negative contact was a bit loose but that wasn't the culprit as I had disconnected the battery prior to that and didn't tightened back up.

I want to thank you for helping out. So the culprit ended up being the NSS I guess it wasn't designed right, it only lasted 300,000 and 24 years I should probably do a written complaint to corporate to make sure this doesn't happen again, jajaja these things go on and on. (NO COMPLAINTS HERE). In comparison my sequoia isn't built with half the quality this was built 24 years ago.

Well I'll read you later.


Gio.:bounce:
 
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