the twilight zone

Both relays were put back in place after I removed the jumper wire for testing.

 

i see you just forget to mention that .

you had the relays or they were in the truck someplace ?

then the starter relay worked correct?

 

Looks like it must be missing the ground to Pin 2 of the Starter Relay so they substituted the ground from Pin 4 of the Heater Relay.
They both come from the J10 Junction connector which looks like it's in the underhood fuse box, I bet there's something going on in that connector.
Doesn't explain the truck cranking on it's own though, any aftermarket remote start installed?

 

The 'starter' engages correctly when that bare wire is in place.
As for the 'starter relay' working or not, all I can say is that I'm not sure given that when the wire is there the starter engages. When its not the starter receives zero juice. Could that wire just be bypassing what the starter relay normally does?

 

nope. nothing like that at all.
Thanks for the diagram.
This might be a dumb question, but could I test the starter relay using a regular multimeter or do I need something more specialized for those larger relays?

 

I'd use a test light, you can connect it to battery positive to check grounds and battery negative to check powers.
If it works with that wire in place and doesn't with it removed the only thing it really can be is an open in the wire between Pin 2 of the Starter Relay and Pin E of the J10 Junction Connector.

 

I'll give it a shot tomorrow. Thanks.

 

Here's the full starting system wiring diagram if you need it.

 

I have an ideal....need to find if that #4 is giving u juice....or a ground path....

What happens if the blower switch is completely off when u start the truck...
and same with the blower on .......

#4 should not have juice unless 3 and 5 are powering/throwing the relay...ON THE HEATER RELAY...hence blower off....

if 3 and 5 are off.....then #4 may be the only ground path for the starter relay to energize correctly.....cause #4 should not have power at that point...only connected either 3 or 5......

 

Pin 4 of the Heater Relay is always ground.

 

So if you use that as a ground....you're using the blower as a ground route?
and not using the blowers ground....but shooting straight into the blower....every time you crank the starter...

Otherwise on this diagram when you closed the heat relay.....the battery would shoot straight to ground and not go thru the blower or ac circuit....least resistance route...

 

...

 

I did little more diggin.....on a manual if your clutch is not pressed in...
you will not get a ground in #1 on starter relay.....

So would the same happen in an Auto if neutral safety switch was bad on the tranny...
could it be that NS switch went out and they jerry-rigged it to start....
does the NS switch provide a clear ground when its happy....in neutral or park...
to the starter relay....

those are kinda pricey.....$120.....I can see where a paper clip would be alot cheaper...

 

Not the case, both Pin 2 of the Starter Relay and Pin 4 of the Heater Relay are grounds always. The only way they wouldn't be is if the wire going to that pin was broken which seems to be the case at Pin 2 of the Starter Relay since it has to be jumped to Pin 4 of the Heater Relay in order for the truck to start.

When the Heater Relay is energized the contact (connected to Pin 2) in the relay moves off of Pin 4 and connects to Pin 1 (Power from the Heater Fuse) thus connecting it to power and turning the blower motor on. Pin 4 of the Heater Relay is always ground, it can't be anything else unless the wire going to it is broken.

Now if multiple grounds or main grounds are bad and stuff starts backfeeding through said bad grounds... well strange things can start happening...

Why not just fix the original problem (broken wire) instead of doing all that?

 

Yeah it makes no sense to tap a ground off something else...
need to find why there is no ground for starter relay....

someone or something has altered that....
we could of been yakking last couple hours over a simple broken lead under the fuse box...
I just wanted to know what provided the correct/original ground....

if it was manual I'd say go check your clutch switch.......






According to this.....that ground has to come thru either the clutch switch or NS switch....


https://www.tacomaworld.com/threads...ay-and-where-does-it-go.803616/#post-28807964

 

So I think is the neutral safety switch ....or the wiring inbetween these...

or it could be out of adjustment if that adjustment bolt was lose...

that would explain crazy things happening during big rain events......


At least now I know how to by-pass it if goes out on the road...

cool beans....you guys....inspire me....

 

That diagram is for a 96 4cyl, OP has an 01 V6.
I posted the correct diagram for the OPs truck in post 49.
Pin 2 of the starter relay should be connected directly to ground through the J10 Junction Connector.

 

I get it....different color wires....but same concept....similar paths...
same devices....

 

Yea same safety switches but on the 01 they are on the power side instead of the ground side.

 

Your saying the pin 2 slot in the fuse box for the starter relay..... always goes straight to ground....
no if, and, buts....

And yet his does not....at least for the moment...


I will go test mine tomorrow and see if that is true....
both in park and in drive.....

at least I'll find out what pre 2000's do.....

I'll see which slots are grounded and which are 12v...
with the shifter in different positions...