1HD-T Starter Motor

[Douglas S]

For anyone curious, the changeover is simple to do.

The main power cables are fairly straightforward. Bat + directly to the post on the starter.

The issue is that the factory starter relay (that activates the starter solenoid) is controlled by both the ignition switch and the voltage converter timer. Power comes in to the relay coil from ignition switch (crank position) and is grounded through the voltage converter timer. Once the voltage converter relay is removed the voltage converter timer will no longer ground the starter relay coil and the starter solenoid with not get power when the key is in the crank position.

My fix for this was to disassemble the connector that controls the starter relay coil and remove the ground wire and extend it to ground on the starter relay mounting bolt. At this point the starter will operate as it did before the conversion.

 

[FJRanger]

For anyone curious, the changeover is simple to do.

The main power cables are fairly straightforward. Bat + directly to the post on the starter.

The issue is that the factory starter relay (that activates the starter solenoid) is controlled by both the ignition switch and the voltage converter timer. Power comes in to the relay coil from ignition switch (crank position) and is grounded through the voltage converter timer. Once the voltage converter relay is removed the voltage converter timer will no longer ground the starter relay coil and the starter solenoid with not get power when the key is in the crank position.

My fix for this was to disassemble the connector that controls the starter relay coil and remove the ground wire and extend it to ground on the starter relay mounting bolt. At this point the starter will operate as it did before the conversion.

Thanks! Waiting for my starter now. It shipped on the 24th and when it gets here I'll be following suit.

 

[Douglas S]

 

[IanB]

Well, that sounded like it cranked over just a quickly as my 24V starter, is it more noticeable when it's cold (like -20C and worse)? Or do you just not deal with "cold" starts anymore now that you have a webasto?

 

[Douglas S]

Well, that sounded like it cranked over just a quickly as my 24V starter, is it more noticeable when it's cold (like -20C and worse)? Or do you just not deal with "cold" starts anymore now that you have a webasto?

Hard to say, I didn't start it at all this winter (actually didn't even have it plated). I pretty much always use the Webasto on cold starts, but I'm going to see how it starts without it next winter.

 

[wrongway around]

I've had mine for a few years. Definitly wouldn't want it if i lived in the -20 climate . But -5ish pretty much the same. I did it to free up a battery for camping, no regrets. I have had to jump it with the extra battery after being left in the extreme cold for a couple of days .

 

[B Point]

For anyone curious, the changeover is simple to do.

The main power cables are fairly straightforward. Bat + directly to the post on the starter.

The issue is that the factory starter relay (that activates the starter solenoid) is controlled by both the ignition switch and the voltage converter timer. Power comes in to the relay coil from ignition switch (crank position) and is grounded through the voltage converter timer. Once the voltage converter relay is removed the voltage converter timer will no longer ground the starter relay coil and the starter solenoid with not get power when the key is in the crank position.

My fix for this was to disassemble the connector that controls the starter relay coil and remove the ground wire and extend it to ground on the starter relay mounting bolt. At this point the starter will operate as it did before the conversion.

Douglas. Did you happen to take a picture of where all this is happening? I can't wrap my head around the 12 volt to 24 volt process. I'd like to just delete it so I can have a 2nd battery for camping and all that. I really don't need the 24 volt flash start... even as impressive as it is.

 

[Douglas S]

Douglas. Did you happen to take a picture of where all this is happening? I can't wrap my head around the 12 volt to 24 volt process. I'd like to just delete it so I can have a 2nd battery for camping and all that. I really don't need the 24 volt flash start... even as impressive as it is.

I didn't, but there are really only two locations that you need to be concerned with. The series-parallel solenoid (located right beside the engine bay fuse box) and the starter relay (mounted to the LHS inner fender near the antenna motor).

The wiring isn't super complex, but some things are tricky. For instance I learned that the same wire that feeds power to the starter relay is also used by the alternator to sense voltage. I had attached this to the starting battery and my alternator voltage was completely unregulated unless the batteries were combined. Moved it over to the other battery and no issues.

 

[B Point]

Thanks for the reply. When or if I get into it I may give you call if you don't mind. Right now I'm debating of leaving what ain't broke alone and contemplating a third battery back where the spare tire used to be. The space is cavernous and could easily have a battery tray of some kind mounted. I'm not too sure about a cable run that long though. Lots of things to research either way. Cheers..

 

[Douglas S]

Thanks for the reply. When or if I get into it I may give you call if you don't mind. Right now I'm debating of leaving what ain't broke alone and contemplating a third battery back where the spare tire used to be. The space is cavernous and could easily have a battery tray of some kind mounted. I'm not too sure about a cable run that long though. Lots of things to research either way. Cheers..

Absolutely. If you have any issues just PM me.

I also considered a rear mount battery, I actually still am considering it. the RHS battery tray would be the perfect location for an A/W intercooler.

 

[wrongway around]

I actually have a third battery on top of my cruisin off road transfercase skid plate.

 

[veiloctane]

For anyone curious, the changeover is simple to do.

The main power cables are fairly straightforward. Bat + directly to the post on the starter.

The issue is that the factory starter relay (that activates the starter solenoid) is controlled by both the ignition switch and the voltage converter timer. Power comes in to the relay coil from ignition switch (crank position) and is grounded through the voltage converter timer. Once the voltage converter relay is removed the voltage converter timer will no longer ground the starter relay coil and the starter solenoid with not get power when the key is in the crank position.

My fix for this was to disassemble the connector that controls the starter relay coil and remove the ground wire and extend it to ground on the starter relay mounting bolt. At this point the starter will operate as it did before the conversion.

I am trying to to put this into a picture in my head on how this was wired up? would it be possible for someone to post or make a wire diagram so I can have a visual on how to do this.

 

[Youngster]

Does anyone have a step by step to this for beginners? I maybe be experiencing the same problem. Hopefully this will fix it. I will be checking my fuses and my batteries later today. But long story short my 1hdt has been running top notch for the past 3 years had no issues whatsoever and yesterday I went out to start to go to work and truck would not turn over. All the light come on and it does crank and crank but does not turn over completely.

 

[asutherland]

I'm bringing this thread back to life as it's relevant to what I am dealing with.

I had my OEM 24v starter rebuilt last year. A couple times since, the starter has "stuck on" after firing up the truck. When I turn the key to Off, it continued to run for a moment, sometimes longer. So I removed the starter again, we opened it up and replaced both contacts and the spring (again). Everything seemed clean and functional.

Few weeks later, it stuck on again. To the point I had to disconnect <both> batteries to stop it from running. When Jason (Cruisin') did my 1HD-T swap, he ditched the 24V timer and Hold warning relay, so basically the starter solenoid is wired through the starter relay from the 24v post (through a fuse). When the starter was running away, I yanked the fuse, and nothing changed. Yanking that fuse would have cut the power to the starter solenoid. Which means something in the starter itself is wrong and sticking on.

At this point I'm looking at what @Douglas S did and thinking I should just swap the starter with a new 12V one and ditch the switchover solenoid etc.

 

[IanB]

I'm bringing this thread back to life as it's relevant to what I am dealing with.

I had my OEM 24v starter rebuilt last year. A couple times since, the starter has "stuck on" after firing up the truck. When I turn the key to Off, it continued to run for a moment, sometimes longer. So I removed the starter again, we opened it up and replaced both contacts and the spring (again). Everything seemed clean and functional.

Few weeks later, it stuck on again. To the point I had to disconnect <both> batteries to stop it from running. When Jason (Cruisin') did my 1HD-T swap, he ditched the 24V timer and Hold warning relay, so basically the starter solenoid is wired through the starter relay from the 24v post (through a fuse). When the starter was running away, I yanked the fuse, and nothing changed. Yanking that fuse would have cut the power to the starter solenoid. Which means something in the starter itself is wrong and sticking on.

At this point I'm looking at what @Douglas S did and thinking I should just swap the starter with a new 12V one and ditch the switchover solenoid etc.

I've had my starter stick on a few times, not a fun experience! I replaced the contacts and plunger and had no further issues. That was a long time ago, I can't even remember if it was my current or previous truck, but I think it was the '91.

Cutting power to the starter and having it stay stuck engaged makes me think the contacts are welding together/sticking, same mode of failure as I rebuilt my starter for, it was never about staying engaged, but rather being unable to disengage. Another rebuild is like $30 in OEM parts, and worth a try. Use only OEM parts after your past experiences.

On the other hand, you're in the Okanagan, and have a Webasto, so cold-cold starts shouldn't ever be a real issue for you and 12V would be just fine, there's no wrong answers in your instance.

 

[asutherland]

I've had my starter stick on a few times, not a fun experience! I replaced the contacts and plunger and had no further issues. That was a long time ago, I can't even remember if it was my current or previous truck, but I think it was the '91.

Cutting power to the starter and having it stay stuck engaged makes me think the contacts are welding together/sticking, same mode of failure as I rebuilt my starter for, it was never about staying engaged, but rather being unable to disengage. Another rebuild is like $30 in OEM parts, and worth a try. Use only OEM parts after your past experiences.

On the other hand, you're in the Okanagan, and have a Webasto, so cold-cold starts shouldn't ever be a real issue for you and 12V would be just fine, there's no wrong answers in your instance.

I agree with your diagnosis! However, this is the second time the contacts and parts have been replaced (with OEM Denso). John B did it with me so I know it was done right. And that was only a couple weeks ago.

 

[IanB]

I agree with your diagnosis! However, this is the second time the contacts and parts have been replaced (with OEM Denso). John B did it with me so I know it was done right. And that was only a couple weeks ago.

Might be haunted? How much more is a 12V starter conversion than a rebuild kit in the meantime?

 

[Douglas S]

I'm bringing this thread back to life as it's relevant to what I am dealing with.

I had my OEM 24v starter rebuilt last year. A couple times since, the starter has "stuck on" after firing up the truck. When I turn the key to Off, it continued to run for a moment, sometimes longer. So I removed the starter again, we opened it up and replaced both contacts and the spring (again). Everything seemed clean and functional.

Few weeks later, it stuck on again. To the point I had to disconnect <both> batteries to stop it from running. When Jason (Cruisin') did my 1HD-T swap, he ditched the 24V timer and Hold warning relay, so basically the starter solenoid is wired through the starter relay from the 24v post (through a fuse). When the starter was running away, I yanked the fuse, and nothing changed. Yanking that fuse would have cut the power to the starter solenoid. Which means something in the starter itself is wrong and sticking on.

At this point I'm looking at what @Douglas S did and thinking I should just swap the starter with a new 12V one and ditch the switchover solenoid etc.

As a bit of an update to this thread (was that really 10 years ago...) I did not have very good luck with the 12v Bosch starters. Took two of them dying in relatively short order before I bought a new OEM starter. That starter has been installed for a few years with no issues.

 

[asutherland]

As a bit of an update to this thread (was that really 10 years ago...) I did not have very good luck with the 12v Bosch starters. Took two of them dying in relatively short order before I bought a new OEM starter. That starter has been installed for a few years with no issues.

Hey Douglas, you stayed with 12v though right? No issues as far as that went?

 

[Douglas S]

Hey Douglas, you stayed with 12v though right? No issues as far as that went?

I did, no regrets on my end regarding the conversion. Was nice to be able to isolate a battery for loads when camping etc, but less of an advantage these days with all the portable lithium power packs available.

I haven't winter driven the truck since but I have driven it in the winter, if that makes sense, and never had an issue starting after using the Webasto or plugged in when the temperature called for it.