autos don't iirc.
87 4Runner random stall and no start
- Thread starter thetoyotaman
- Start date
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- #22
The only relay I see in the fuse box under the hood says "head."
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- #23
My understanding is that the autos don’t have a relay which I can’t find one anyways. And basically the starter wire runs straight from the ignition switch. I replaced the switch so there could be a break in the wire somewhere in between. I need to verify all of this with the wiring diagram, but I really don’t know how to read one either 
pretty straightforward.My understanding is that the autos don’t have a relay which I can’t find one anyways. And basically the starter wire runs straight from the ignition switch. I replaced the switch so there could be a break in the wire somewhere in between. I need to verify all of this with the wiring diagram, but I really don’t know how to read one either
would be a good idea to add a relay anyway.
old ass wiring has voltage drop.
here's the diagram
As gnob showed, it's not straight from the ignition switch to the starter. It does travel to the neutral start switch on the transmission. From the switch it then goes to the starter.My understanding is that the autos don’t have a relay which I can’t find one anyways. And basically the starter wire runs straight from the ignition switch. I replaced the switch so there could be a break in the wire somewhere in between. I need to verify all of this with the wiring diagram, but I really don’t know how to read one either
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- #26
When it doesn’t work I’ve tried shifting it and juggling the shifter around Park and Neutral to see if that makes a difference, but no change. Good reminder to look into the switch. Whats weird is how the truck can start several times and then not in place without shifting so not sure about that switch.
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- #27
Update: Rebuilt the neutral start switch. So far so good. Used baking soda and lemon juice paste to polish the contacts. It cleaned up real well. Cleaned out the old grease and used marine grade diametric. The problem was the copper contacts that are spring loaded brushes were stuck with old grease hardening. Still need to add a starter relay and figure out how to replace the white fusebox wire in post #14 if anyone knows how. @cruiserdan ?
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- #29
Igniter wire harness and neutral safety switch rebuild seems to have fixed most starting/stalling issues except for an occasional stall I think is mostly the idle air control valve that is not working. Is it repairable at all? I don’t know where to find one.
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- #30
No start today. Only thing that happens when key on or start is charge light on. AM1 fuse blown but why?
the main pull behind that fuse is the starter and related wiring.
so potentially something with that wiring or the ignition switch itself. or some kind of direct short.
it would be a good idea to wire up a starter relay because the wiring voltage drop WILL eventually become a problem.
do you have a factory wiring manual?
if not i can link you my 86.
so potentially something with that wiring or the ignition switch itself. or some kind of direct short.
it would be a good idea to wire up a starter relay because the wiring voltage drop WILL eventually become a problem.
do you have a factory wiring manual?
if not i can link you my 86.
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- #32
Is a factory wiring manual for 87 different than the factory servers manual?
Oh heck ya. The Electric Wire Diagram (EDW) manual is worth their weight in gold. The FSM is a joke for wiring ... it's too basic. The EDW gives you pin out of each terminal/connector.
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- #34
Please. Thank you. I need to learn how to read them.
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- #35
Checked alll the fuses under the hood and under the dash and all are good. No burnt wires noted. Looks like I'm going to have to dive deep here as there aren't any other clues.
For you electrical experts out there, if I put an amp meter on the 40A terminals that blew and turned the key to on, would the reading give me clues?
For you electrical experts out there, if I put an amp meter on the 40A terminals that blew and turned the key to on, would the reading give me clues?
This may seem like a total nightmare suggestion but it might be worth pulling the engine wiring harness completely out and going through it very carefully. I’ve had multiple people who started having weird electrical problems with no luck and were able to find the root cause by unwrapping the original electrical tape/conduit and finding rub outs and corroded connections.
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- #37
That would be a job for sure. Sounds like a plan when I do the frame off restoration lol. I guess I was curious if I could measure the load off the circuit that blew as part of troubleshooting.
You can check continuity to ground using the tone feature on a meter. See if there are any shorts. You could use a dc amp meter and see what it’s pulling but I’m not sure what the normal amp draw on that circuit should be. I’d guess something is shorting out. The engine harness isn’t terrible to remove. Unplugs from the ecu through the pass firewall. Breaking down the plenum is the hardest part. After that everything unplugs. Probably could be done in 2-3 hours.
This. Especially the wires to the injectors. Those wires have a ton of crimp splices that corrode.
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- #40
Well, following the EWD to what powers the blown 40A, I'd have to rip it out from the fuse box to the tail lamps.
