Starter relay

[Doctor J]

As I noted, many TN forum users have reported the intermittent no crank- no click condition, commonly happened in 2nd generation Camry and 86-89 Celica despite the GOOD battery
This problem often takes place after extended driving when the starter is getting hot due to the engine heat. The starter can operate, however after it cools down in about 45 minutes.
During the no start, no click condition, the starter operates if the power applied to its “ignition” [clip type] terminal from the battery positive post with remote starter switch.
Therefore many owners of affected cars just installing pushbutton switch under hood.
“Extensive studies” conducted by yours truly, discovered that bypassing the neutral start switch or getting power from the hot terminal of ignition switch [AM1] are not helping.
As a result, based on common practice I desired to wire relay, so the power from ignition switch will flow trough the relay coil instead of going trough the starter solenoid windings that require more then 15 amperes at hot condition in order to operate [pull the plunger, engage pinion gear and pre-rotate motor]


I used Single–pole, single-throw normally open relay with coil rated at 12 V DC; the main contacts are rated at 25 plus amper [40 A on mine].
You will need to use 16 gauge, stranded wires, with insulation rated to 80 degree centigrade;

• 4 female spade terminals
• 2 butt splice terminals and
• 2 ¼ inch ring terminals

To install[refer to figure below]:

• Disconnect the negative terminal from the battery
• Cut the thin black wire to solenoid about 3 inches from its end [remove and discard its jacket as necessary], unclip this wire from solenoid
• Attach this 3 inch piece to “87” terminal on the relay [relay switch pole-to starter], add wire length as necessary
• Now connect the black wire that ran originally to the starter solenoid to the terminal “85” of the relay [to the relay coil],
• Connect another coil end terminal [86] to the good ground [igniter bracket] using ring terminal [white wire on my car]
• Finally, connect relay terminal “30” to the power source [the circuit side of 80 or 100 amp alternator fuse link [blue wire on my car]
  
• DO NOT CONNECT THE BLACK WIRE TO THE SOLENOID IGNITION TERMINAL AT THIS POINT!
• Attach the battery negative terminal.
• Operate ignition switch to start [if engine is cold, disconnect cold start injector, to prevent flooding].
• If relay clicks, it is wired correctly, so connect the black wire to the solenoid.
• Start the engine.
  

Note:

• if solenoid clicks, but starter is not working, the relay won't help-- check the solenoid contacts and thick battery cable connector;
• If remote starter cannot make the starter crank and the solenoid plunger is not moving, the starter is defective [open pull-in solenoid coil, open starter winding, or bad brushes]

P.S: Should this thread be stickied??

[normalize]

Very helpful post, thanks Doctor J

[disregard]

This is great information ! Thank you doctor J

[WannaBButch]

Worked like a charm. I don't have to use my starter button anymore to start the car. Woo hoo!

[jasonck08]

I'm trying to wire up a relay that triggers a hydrogen generator that I just made. I want to make it so it only runs when the engine is on. I have a 40 amp relay, but just do not know exactly where to connect the wires. One goes to the ground and the other???

[fairladyZX]

I just want to say Thanks again to Doctor J. for posting this very helpful thread. Also thanks so much for helping a fellow forum member out installing the relay on my camry. My engine bay was a mess until Doctor J. gave it a through exam and fixed everything back where they belongs. Now it starts like a brand spanking new car again.....hehehe.

I can't say Thank You enough!!!

[Doctor J]

Thanks for compliments; I also saw again what can happen if someone is using the impact tool to tighten bolts into aluminum part

[atobe]

hey come and install it on my car too !!!!!!

[malayan]

WOW... Not all of us are rocket scientists.


I would rather

just run a remote starter switch in under the dash!

Dr. J has been very helpful thogh!

[WannaBButch]

Here's the short and sweet for all who are like me and don't have the attention span to read all the directions. These are the ones I followed and they worked great.


The relay you need is available at most autoparts stores, it is sometimes used for light accessories such as off-road lights of fog lights, the part number is 610T, 12VDC,30-40AMP rating.
The terminals are marked with numbers, connect it as follows:
Locate the relay as close to the starter as possible, find a place to bolt it on to the frame or any other metal surface.
Connect the #30 terminal on the relay directly to the battery with 10 gauge wire and suitable connectors to the positive terminal of the battery.
Remove the small connector from the starter, it will be used later, connect the #87 terminal from the relay to the starter's small terminal(the one just removed)the terminal on the starter, NOT the wire connector just removed.
Connect the #86 terminal on the relay directly to ground.
Connect the #85 terminal on the relay to the wire that was removed from the starter earlier this wire should be black/yellow or b/w

[Doctor J]

10 ga wire size is overkill; 16 should be good enough.

[atobe]

25A is ok too since that's all they had at my local radio shack(who still goes there ? ).. and since the starter's close to the battery i just grounded it to the car's battery

[dataeagle]

Does this fix work on a '91 4 runner with the same issue?

Thanks in advance

[WannaBButch]

From what I hear it does. That where I originally got my directions from on how to do it.

[Doctor J]

this repair was originally suggested by Ted Ritter for his own Rav-4