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· Registered
9 Posts
Discussion Starter · #1 ·
The original 2000 Sienna starter got stuck on and consequently got pretty hot before the minivan was shut down.

I replaced the starter, turned the key to start and not a sound/silence. I then had my son turn the key again to "start" and measured the voltage at the incoming (small diameter) solenoid wire to the starter and measured 12.55 with key turned to "start"

I then disconnected the solenoid wire, had him turn the key to the "on" position and used a jumper wire from the hot side of the battery to the solenoid contact.

The solenoid kicked in, the starter cranked and the car started without problems.

I reconnected the solenoid wire and tried jiggling the shifter between P and N -- no help. I tried different help there. I continued to read 12.55 on the solenoid wire whenever the key was in the "start" position yet it was silent every time unless I jumpered directly from the battery.

I returned the starter got another one, had the shop bench test the replacement and it was fine. I installed that one and the same thing happened...Dead/Silent with key turned to "start" yet I read 12.55 incoming at the solenoid (small diameter) wire. Disconnected the solenoid wire, reconnected the jumper wire and starter number two started the car.

I've since installed a fused spring loaded toggle switch and start the car with the key to "on" using the toggle to kick in the solenoid.

All fuses test good. I know there is a starter relay ($71.00 from Toyota) and an ignition switch which I think is located in the steering column and most likely a PIA to replace. Any thoughts on how to replace the ignition (not keylock) switch would probably be helpful at this point.

I'd like to fix this but don't want to shotgun parts, especially electrical stuff as they are difficult to return and get your money back on.

Any ideas why I see 12.55 on the solenoid wire when it's connected to the starter and the key is turned to "start" (shifter in either P or N) yet nothing happens.....dead/silence....yet when I jumper directly to the solenoid contact on the starter from the battery it starts every time? It makes zero sense to me.

Thanks for any help

· Registered
395 Posts
Diagram for my 2003 Sienna.

There are 2 electrical connections to the the ground.
1....should be the big connected directly to the positive terminal of the battery, no fuse, no relay.....
2nd.......same color wire as above......comes from the start relay......also +12 volts....through the relay contacts......from 40amp "Main" fuse.
You need +12 volts to BOTH terminals to engage the starter.
The 2nd wire connects a contact inside the starter to make it work.

In short......the big fat wire from the battery gives you +12V all the time.
When you turn the ignition key to "START" get +12V to the other terminal to make the starter work.

Start relay.....Pins 1 and 2 are the coil.....
Ground always to Pin 2
Pin 1 gets +12V through pins 5 to 6 of the transmission "park/neutral" switch and the 5amp "Starter" fuse.....from the Start wire on the ignition switch (red wire).

If you are always seeing the +12V at the switched terminal......check what you are using for ground......also....disconnect the lead and see if you get the +12V from the LEAD.....if not....that is the problem.

· Registered
9 Posts
Discussion Starter · #3 ·
Thanks wiswind...I'm still a bit confused as to what's not working

The battery lead (big wire) going to the starter is fine.

Ground wire to chassis is tight and clean.

When I turn the key to "on" and jumper from the battery directly to the solenoid terminal the solenoid kicks in and starter motor starts the car.

When I reconnect the van's solenoid wire back onto the solenoid......different result.

That small diameter wire, from the wiring harness, going to the solenoid measures 12.55 when I turn the key to the "start" position yet there is silence at the starter motor.

I measured voltage both with that wire connected to the starter solenoid (under load) by probing thru the wire's insulation with a sharp pointed probe and measured voltage with it disconnected from the starter and in both cases I see 12.55 but here is no response from the starter. The starter only kicks in when I bypass the van's solenoid wire and power it directly.

I'm unclear as to why I see the correct voltage at the solenoid when I turn the key to start in either P or D and I get silent response. Yet when I disconnect that little solenoid wire and jumper directly to the solenoid terminal with the key to "on" the car starts. The 5 amp starter fuse is good.

Are you saying you think the start relay is faulty?

If it is, why do I see 12.55 at the solenoid when I engage the key to the start position when using the van's solenoid wire coming from the wiring harness? And why does nothing happen at the starter when 12.55 hits it thru that wiring harness wire?

My current start circuit goes through a high current 30 amp spring loaded toggle -- one side goes to the solenoid and I'm pulling power from the power door circuit from inside the interior fuse box. The wiring harness solenoid wire is disconnected.
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