80 won't start

[Darwood]

Well I got back from vacation last Wednesday and my wife tries to start the truck Thursday to go to work and it won't start. I figure the battery is just dead. We don't have time to jump it so I drive her to work.

I finally get time Saturday to jump the truck and it still won't start. When I turn the key to start position I get no noise at all. No click of the starter. Lights work and when I check to voltage at the battery I get 12.5 volts when the truck is off and 12.3 volts with the key on the on position. I've looked at the fusible link and it looks ok, but I need to go check the continuity on it.

So right now I think it could either be the starter of the neutral/park switch. I tend to tink it's the neutral/park switch since I've been periodically getting a P1780 as per this thread:

https://forum.ih8mud.com/showthread.php?t=70090

Also the starter was replaced by the PO with a remanufactured unit. I only know this because it says remanufactured on the starter.

I'll be working on the truck today so I'll update what I find. I'm going to eliminate the fusible link first then look at the neutral/park switch. The best part is I get to work in the rain. (yay!)

If anyone has any other suggestions I'd appreciate it.

 

[Cruiserdrew]

Derek-I would swap in a known good battery before I did anything else. That would make the most sense given the extended down time of the truck. If that fails, you'll need your volt meter to see if there is power to the starter and work from there. Good luck, I hope it isn't serious.

 

[Darwood]

Thanks Andy. I just tried starting with a good battery and still nothing. I finished checking the neutral/park switch voltages at the ECU and that checked out fine. I also just checked the continuity on the fusible link and that was fine too.

One thing I just noted was that the clock dims out when I try turn the key to the start position. However it does this when the gear selector is in D or anyother drive gear.

I guess I need to check the starter next.

Did I mention this is fun in the rain?

 

[rockclmbr]

Derek,

Bummer the Neutral switch checked out okay. That still leaves some guesswork. I would check all fuses, escpecially IGN adn ECU???

Short of completely removing the starter, you could jumper the starter directly to the battery to see if it spins. Just don't connect it too long or you will have a dead starter.

If it is infact the starter and you have a lower powered starter, I have the contacts for that. I ordererd both sets at the time.

Look on the bright side, at least your windshield isn't leaking anymore with all this rain!

 

[Darwood]

Thanks Jasper. Jumpering the starter is the first thing I should have tried. Luckily it wasn't raining when I just went to do this. The bad news is the starter worked. The good new is jumpering the starter eliminated both the battery and the starter as being a problem.

So now it seems that something is wrong with the ignition. I think the ignition switch is fine since the clock dims when I turn it to the start position. Or this could indicate some short?

I've also checked all the fuses and they seem fine. Think I'll double check.

The FSM has 2 procedures for checking a P1780. One starts with checking the voltages at the ECU and the other checks continuity on the park/neutral switch. If the first test passes then you check the one you didn't check in the first step. The only thing I can think of now is to check the continuity on the park/neutral switch.

I think I need the wiring diagram manual now.

 

[Darwood]

I just checked all the fuses and they are all fine. I also don't think I need to check the continuity on the switch since checking the voltages should be good enough. So if I'm reading my manual right then it's looking like an ECU issue.

To check the ECU the FSM specifies that I should check the ECU ground, however I'm not sure which pin this is. I wonder if my Haynes has that info...

 

[Junk]

You say all the fuses are fine, are you sure you checked the 7.5A IGN fuse?

 

[Darwood]

You say all the fuses are fine, are you sure you checked the 7.5A IGN fuse?

Yep double checked and also swapped in an unused 7.5A fuse to make sure the fuse was good. Funny thing is I can't find where this fuse fits in for the ignition. It doesn't appear in my Haynes wiring diagram or the small diagram in the FSM which shows the wiring for the park/neutral switch.

I checked the voltage of the black/white wire going into the park/neutral switch and got about 9 volts. I then checked the voltage at the starter connector (black/red wire that charges the solenoid) and got about 3 volts checking against the dirty frame for ground. To make sure I wasn't getting a voltage drop at the park/neutral switch I jumpered the black/white and black/red wires together and got the same reading at the starter connector. When the black/red wire comes out of the park/neutral switch I loose it when it goes over the transmission. I then can only find it again where it goes to the starter so it's hard to tell what the wire is doing.

I'm now wondering how much voltage the solenoid needs and also if my problem could be a sticky plunger? The starter works with a full 12 volts directly from the battery, but maybe due to the condition it's in it won't work with the lesser voltage as provided by the wiring harness?

I guess I should also check the resistance of the black/red wire starting from the park/neutral switch and ending at the starter connector.

 

[landtank]

I also don't think I need to check the continuity on the switch since checking the voltages should be good enough.

Nope not even close. It's very common for a switch/relay to be able to pass voltage but not be able to pass amperage. I'd jump the switch/relay out to be sure.

 

[Darwood]

Nope not even close. It's very common for a switch/relay to be able to pass voltage but not be able to pass amperage. I'd jump the switch/relay out to be sure.

I've jumped pin 5 and 6 on the connector to the park/neutral switch and this didn't seem to have much effect. I jumped it with 20 gauge solid core copper wire. It's a little small but should be fine?

I'm stumped. I'm back to thinking maybe it's the starter as stated above. It will run with direct 12 volts to the connector but not with anything less? I had a look at my starter and it seems to be a remanufactured Lucas unit. Did Toyota ever put Lucas components on their vehicles? I thought only Land Rovers used Lucas "prince of darkness".

 

[lacruiser]

try this

Derek, I think maybe you've got a wiring issue somewhere. If I were you, here's what I'd try. for safety reasons, prevent the engine from starting up by either disabling the ignition system or maybe disconnecting the crank angle sensor at the front of the motor.

Then, have someone hold the ignition key in the start position while you go around and move wires around. Push, pull, twist, etc until you get some action at the starter. I've used this kind of technique to isolate trouble spots in the wiring harness before. It's not foolproof, but it may point out your problem.

I don't know what the signal voltage at the solenoid is supposed to be, but 9v sounds kind of low to me. You say youv'e got 9v going "out" of the NSS, or "into" the NSS? From what I read it's the same, right because you jumperd them together? If so, then maybe the problem is the ignition switch itself.

before doing the above, try this first:
I haven't had the ign switch apart on these trucks, but sometimes the electrical portion (as opposed to the lock portion) will be comprised of a two-piece assembly that's either riveted or screwed together. sometimes these two pieces will slightly pull apart, and the contacts inside won't make contact, and the switch malfunctions. If you can, try and push on the back of the "electrical
portion" of the switch, while holding it in the start position. if necessary, grab the bundle of wires coming off the switch, and push them toward the switch, I'm not sure of the access under there. Hopefully the starter will engage. I've seen this as the problem on several vehicles.

If this doesn't do it, I'd try to find out what the voltage is supposed to be at the solenoid signal wire. if it's 12v, youv'e almost certainly got a wiring issue, or an ign switch issue.

good luck

Dana

 

[RavenTai]

it should be 12v

looking at the 96 LX450 EWD next thing I would try is shorting pins 2 and 4 (both black w/ white stripe) on connector S12 of the starter cut realy (alarm controlled)

if that is not it check the voltage of the start lug at the back of the ignition switch with it turned to start. should be close to 12v, there are bare terminal there you can check with everything hooked up, if that is no good check the voltage into the ignition switch with it turned to start, if input is good and ouput is bad ignition switch is bad.

 

[FirstToy]

Derek, if it's the starter - did you try giving the starter a good whack? I know it sounds silly but my friend had a truck w/ a bad starter and he got it to start for awhile with a quick hit or two with the end of a metal rod (tire iron)

SOmething in the starter clicked and it would start. Same symptoms as you and eventually he got a new starter.

 

[Darwood]

Thanks RaventTai, Dana, and James thanks for the leads.

I think I'll need to trace the route for the voltage as suggested. Looks like the black w/ white stripe wire is the one to trace.

Now when I took my voltage readings I think I did it wrong. I disconnected the connector and took the reading off of the pin. My EE is not as good as it should be, but won't this give me the reading from the pin to my ground and not what is seen by whatever is on the other end of the connector. And shouldn't this only be as good a reading as my ground? I tried to get a voltage reading at the NSS but the connector is hard to tap into. I also can't figure out how to tap into the wire black w/red stripe wire right at the starter.

So my 9v reading was going into the NSS, but it really was from the connector to grounf via the DMM. So seeing as I'm probably doing this wrong, what is the right way to tell the voltage? If I'm going to disconnect a connector should I run a wire from the negative terminal to get a more 'accurite' reading?

James, I was able to get the starter to work when I applied a direct 12v to it, so I'm not so sure the broom handle trick is needed.

 

[CJF]

James, I was able to get the starter to work when I applied a direct 12v to it, so I'm not so sure the broom handle trick is needed.

Au contraire: Wouldn't that help pinpoint the (crappy aftermarket get that thing out of there) starter as the problem?



Whack that sucker! (Not kidding; it's worth seeing what the effect is.)

Hang in there,

Curtis

 

[NorCalDoug]

Au contraire: Wouldn't that help pinpoint the (crappy aftermarket get that thing out of there) starter as the problem?



Whack that sucker! (Not kidding; it's worth seeing what the effect is.)

Hang in there,

Curtis

All Toyota starters purchased over the cournter are remanufactured, IIRC. Because it's stamped "remanufactured" doesn't mean it's not a Toyota starter.


Sorry Derek -- no hints/tips for you.
All was fine when you left her sitting?

 

[Darwood]

All Toyota starters purchased over the cournter are remanufactured, IIRC. Because it's stamped "remanufactured" doesn't mean it's not a Toyota starter.


Sorry Derek -- no hints/tips for you.
All was fine when you left her sitting?

Yep all was fine when I left it sitting, well other than the P1780 I got about 3 weeks earlier which didn't return.

As for the starter it had a remanufactured label on it with Lucas on it. Under that was a more permanent label with Lucas on it. I have no idea if it's aftermarket or OEM, however I would expect it to be from Nippon Denso if it were an OEM manufacturer. I'm sure CDan can clarify that.

 

[roncruiser]

Sounds similar to something that happened to me awhile back. Before pointing fingers at the strarter, check the fusible link to the ignition switch. Mine went bad. The supply from the battery to the ig. switch wasn't getting there. "Hot wire" your vehicle... direct connect from the battery to the ignition switch. Then try cranking her. I bypassed the wire that goes directly to the ig.switch with another wire. Started right up. Make sure to put fuse in-line too.

Here's an old thread detailing my past woes.... maybe it will help a little: https://forum.ih8mud.com/showthread.php?t=31372

 

[NorCalDoug]

Yep all was fine when I left it sitting, well other than the P1780 I got about 3 weeks earlier which didn't return.

As for the starter it had a remanufactured label on it with Lucas on it. Under that was a more permanent label with Lucas on it. I have no idea if it's aftermarket or OEM, however I would expect it to be from Nippon Denso if it were an OEM manufacturer. I'm sure CDan can clarify that.

Lucas?

Prince of Darkness Lucas?




My reman'd starter looks and smells like an OEM starter...has Toyota labels where it's supposed to...

 

[RavenTai]

any good ground will do for refrence but it must be a good ground. on something like this you want to check for voltage with a load on the part, so it has to be connected to the eventual end user the starter. like Junk said if it does not have a load you may get a false good reading, ran into that problem tryign to troubleshoot my fuel pump relay.