Weak voltage to starter

[Bob62]

Starter works only intermittently. I thought it was a bad starter but mechanic tells me that it's really low voltage going from ignition switch to starter. When he runs power directly from the battery power is full and it starts every time. He wants to change the ignition switch ("where the key goes in"). Does this make sense?

 

[MTB Land Cruise]

Check out this thread….

FJ60/FJ62 Heavy Duty Battery Cable Sets

The kit costs $155.00 shipped (within US). International shipping is available. The kit includes 5 cables and battery terminal connectors. This kit fits FJ60's and FJ62's. See below for additional kits (FJ40, FJ80 and FZJ80) Kit includes: Battery positive to starter cable (with protective...

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[3_puppies]

Starter works only intermittently. I thought it was a bad starter but mechanic tells me that it's really low voltage going from ignition switch to starter. When he runs power directly from the battery power is full and it starts every time. He wants to change the ignition switch ("where the key goes in"). Does this make sense?

the ignition switch/key barrel wouldn't need to be changed.
on the back of where the key goes there is the actual switch that can be replaced.
if removed you can use a screwdriver to turn the switch
only thing the key switch does is lock the column

assume the guy is running direct power to the solenoid to engage the starter?

 

[micruz60]

Change the corroded battery cables / clamps.

 

[ToyotaMatt]

Starter works only intermittently. I thought it was a bad starter but mechanic tells me that it's really low voltage going from ignition switch to starter. When he runs power directly from the battery power is full and it starts every time. He wants to change the ignition switch ("where the key goes in"). Does this make sense?

the ignition switch/key barrel wouldn't need to be changed.
on the back of where the key goes there is the actual switch that can be replaced.
if removed you can use a screwdriver to turn the switch
only thing the key switch does is lock the column

assume the guy is running direct power to the solenoid to engage the starter?

hi Bob , happy 4th !
- i read several things in your post # 1 above here .....
- making sure to always note your modle year and modle of land Cruiser is super important because as it directly related here the FJ60 & FJ62 have very different electrical key switch parts in the steering columns ......
- if you have a early FJ60 as in 8/80-1982 had a old-skool loaf of bread size-spec. single reduction starter motor on them , and it is absolutely possible that one could have been installed on a later FJ60 or FJ62 , i have seen al these topics before regarding the starter motors
- you say above : Starter works only intermittently ..
- does it do anything at all when it will not properly start your engine like make a loud Clicking sound perhaps , or a high-pitch winding of metal sound ?
- see ......... here is a situation where you have another person ( your mechanic ) involved other then yourself making the fundamental needed correction parts replacement diagnosis for you , as opposed to yourself ....

- what specifically has prompted you to reach out here on MUD and seek 2nd opinions , and why ?
- there is No wrong answer here Bob , it's very good that you have done so like you have here of course ,,,,
- but , knowing more as in much more of the big overall picture here Technical facts speaking , also posting photos of any related parts topics is always super helpful at any level , as opposed to a more general singular one about replacing the Electrical portion ignition switch ("where the key goes in"). Does this make sense?
if not i can try to explain in more detail ?
below are the FJ60 & FJ62 Electrical Key switches , the visual differences below , should help explain what i mention above as well
mat
,

/

 

[caladin]

I'm going to assume you are new to this, so If I explain too much, don't be insulted... just trying to help.

The only thing that's not super obvious is what a solinoid is... it's just a big fat relay, which is just a switch you control with electricity to turn it on and off.. You use a skinny wire to to turn the switch on and off, a fat wire is what gets controlled by the switch. The solinoid on the FJ is a little cylinder built onto the starter.

You use a skinny wire to control a fat wire, thats all a solinoid does.

There are basically 2 separate parts to the starter battery circuit ,
Part #1 the contol circuit (skinny wire)

battery + ---->key switch -------> Starter Solinoid Control (turns starter on and off using low power---> ground

This is a low power circuit, using thin wire that just toggles the solenoid on for the starter, its part of your wiring harness
The power from your switch, is a low power signal that controls the solinoid.

Part #2 The high power signal is usually from the battery to the big lug on the starter. (fat wire)

Battery+====> Starter solenoid Power===> starter Motor ====> ground

Ignore that is diagram is 24v and take a look.
Blue is your fat wire high power circuit.
Green is your low power thin wire circuit. it shared the ground through the body of the starter with the blue circuit.

The first question is is low voltage your mechanic identified to the control circuit (green) or the power circuit (blue)
The thing is, when most people jump a starter they go straight from the battery to the power side, to test, not the control side.

If it's the control circuit, then replacing the switch -MIGHT- work, but it's probably a bad ground or corrosion somwhere in the control circuit, which the swith will only help a little at best. (Otoh, its really easy to swap)

On old toyotas I always start by assuming it's the ground. It's a pain, but you can totally address this yourself. Start by cleaning up all the grounds on the control circuit..


My guess is it's the power circuit. Luckily thats stupid easy to upgrade so it works better. 4 bolts and 2 thick ass wires. that's it. You can 100% do this your self, if you can turn a few bolts and operate a tape measure.

I had the same problem with the starter on my Fj40, I added a new big fat ground wire (2awg or thicker, marine grade wire is better) from a mounting bolt on the starter right to my battery -, and it went away. I didn't even remove the old wire , just ran a new one in parellel.

If you also add a big fat wire from your battery + to the + lug (Big) on the power side of your starter solinoid, that would be even better, I need to do this on my 40.

I suggest 2awg or thicker, I'd probaly go 2/0 (double zero) and just be done with it , You just need to measure how long a wire you need and order it on amazon.

Here are the parts of the starter, double check I got the big and little wire right, I'm guessing based on the size of the bolt. just look at the wire going to it.

 

[Bob62]

Thanks to all for the helpful replies. I just bought an FJ62 ignition switch from Toyota Matt. We'll see how it works out. This is my 3rd 62; my first was a new one in 1989. First time I had this issue though. Thanks again. This site is filled with expertise.

Bob R

 

[cornboy]

Thanks to all for the helpful replies. I just bought an FJ62 ignition switch from Toyota Matt. We'll see how it works out. This is my 3rd 62; my first was a new one in 1989. First time I had this issue though. Thanks again. This site is filled with expertise.

Bob R

curious if the ignition switch resolved the issue or did you resolve it another way?

 

[Bob62]

Thanks for following up. Mechanic had put in a relay to increase juice to the starter, which did not resolve the issue. Then he installed a new ignition switch: that didn;t solve it either. Finally we saw that the starter was bad because the rod wouldn't go back in. This week installed a reman Toyota starter from the dealer and it works fine now. Thanks for all the help.