Car not starting randomly? READ THIS (30 Amp Starter Relay Mod)

[Nick M]

so what exactly is causing the non start problem? The old harness? The old ignition? Starter? Has anyone pinpointed it yet?

I know it is from 2008, but it was brought back to life.....There isn't a common problem to a Supra that is different on other cars. There are several reasons why a car doens't crank over when the key is in the crank position. You have to diagnose to find out why. Or pay somebody competent.

 

[jimmymc6g]

I know this post is really old, but this just fixed my starting problem! I can't thank you enough.

 

[Poodles]

I know this post is really old, but this just fixed my starting problem! I can't thank you enough.

I sure hope you read the entire first post at least to read the part that says read the entire thread...

 

[jetjock]

The car wins again :nono:

 

[jdmfreak]

.

 

[wingnut89]

can I get a picture of this wired up in car or a copy of the wiring diagram, pretty sure this would fix mine.

 

[jdmfreak]

Read the whole thread!!!

 

[wingnut89]

Thanks for the help

 

[IndigoMKII]

Oh man, I just read this entire thread. I can honestly say I've laughed out loud a few more times than I should have. The solution was offered SEVERAL times in CLEAR view if you're attempting to find the actual solution and not some quick fix.

This thread is just so full of information that would be better explained to a wall.

 

[wingnut89]

You're probably right, I will read through the whole thing, I understand 95% of what the first post says to do, I just was wanting to see the wiring diagram since it is no longer available. The only thing that had me confused was it doesn't specify (that I saw, could have overlooked it) if I need to splice the new circuit into existing circuit. I wasn't trying to be a pain in the ass, I will go back and read it all, thanks and sorry.

 

[wingnut89]

Disregard, I'm now convinced I'm part retarded.

 

[80083r]

Is it the wing part or the nut part?

I know EXACTLY how you feel.

 

[TweeT91109]

HAHA, I bought my car from this guy. BA

 

[theGOODWIN2012]

I had trouble starting my car once only to find out that it was the [stock]alarm system immobilizing the engine. I had to literally lock and unlock my car with the key 3-4 times, then get in and start it. Started right up.

 

[fienloco]

Im having this problem with my 88. Im just curious to know what exactly do you do with the stock relay how is it bypassed? Is it still in use? Does it get looped after removing the relay? Fill me in on the exacts someone. Please. Im going to get what I need but Im still looking for an answer to those few questions. Thanks.

 

[gsxr141]

yesterday my car decided not to start. first time ever, so i hoped it was something simple. after reading this whole thread, i did some diag. i tested the relay and found it good, i pulled the dome light fuse to see if it was an alarm issue, i then checked for power to the starter with the key turned. everything looked ok so i pulled the starter. i had the store test it and it was bad.
in this case it was actually the starter at fault.
a note to anyone changing their starter......... the bolts are a bitch to get to, and my car had nuts/bolts.........yay.
once i moved the master cylinder, i had enough room to get my meathooks in there.

 

[Dan_Gyoba]

the stock relay how is it bypassed? Is it still in use? Does it get looped after removing the relay?

Here's what this "mod" does:

Take ALL of the stock wiring, the stock relay and everything that goes with it, and use THAT to trigger yet another relay to deliver power to the starter solenoid... Which is really another relay.

Basically it's "I can't be bothered to take the time to figure out what's really wrong, so I'm just going to throw another relay at the problem and hope that it goes away."

The trouble with it is that it's my experience that problems don't just go away. If there is a problem that makes it so that the stock wiring can't trigger the solenoid, then how long until it can't trigger the relay? Will it be harder to fix then?

A previous owner did this mod to my '90. While I've got stuff apart, I plan to track it down and remove it.

 

[Satan]

...But

By using the power/signal wire that goes to the stock relay (TRSM Page ST-12), you would then bypass the stock relay and associated wiring (pay attention if using stock alarm). You would use the signal/wire coming from the ignition switch (ST1). This mod uses the signal/output of the stock relay (#4), which is what Dan's point is. U are just using a weak signal to drive another, but with all of the other pieces (potential faults) still in place.

Basically you need to replace stock components w/aftermarket (or new)... You could argue about fixing this issue all day long, but in the end (after sitting on the side of the road or being late for work too many times), you just want the bitch to start, when you turn the key.

I am getting ready to revisit the mod, since I did it and it worked great, until this latest rebuild. I moved the new relay into the cabin, near the ECU. Now, I can hear/feel the relay trip, but somehow the signal/juice is not enuff to turn the starter (tho it did fine, until recently). I ordered a bunch of wire and a distribution block to do something fancy with it. I believe I need to get closer to the ST1 signal from ignition and bypass any other relays, etc. Basically replace the entire circuit w/new relay & fresh wires.

In the end, there's some flaw in the starting circuit which many of us could not overcome (relay, wires, alarm, or combination of all). There's only been minor success with just replacing the relay and no one has truly documented the root cause/fix... which is why we have this mod (work-around).

 

[jetjock]

Crack me up. How can something so simple bamboozle so many?

 

[Satan]

I've chased it and resolved in several other MKIIIs. Just seems to be a ghost issue in my current one :-/ If it helps, my foglights don't work after the foglight mod, even when I returned things to stock (fuses are good). There're definitely gremlins in my sheeyat.

Easier for me to go end-to-end for the whole starting circuit.