Finding Tachometer Circuit

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JMK
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Finding Tachometer Circuit

Post by JMK »

As it is supposed to go to -29 tomorrow night, I spent the relatively balmy -3 day working on getting the remote start installed. Just about done, but I'm stuck on:

1: finding the tachometer lead. I need to tap into the tachometer wire and get at least 1.8V AC and 1.5 Hz or faster. If anyone can tip me off on where to look for the tach wire, preferably in the engine compartment rather than underdash, it would be much appreciated.

2: Finding the door actuator lock/unlock wires. As the vehicle already has a remote for the doors I assume there must already be something installed somewhere.

3: Does anyone know the current for the electronic rear gate switch? THe remote's module supplies 500mah so I assume I'll need to use a relay to connect it if I want to use the trunk unlock on the remote to unlock the gate.

#1 is the most critical at this time as I have it working but it can't crank properly and won't run more than 8 seconds until it knows what the rpm's are doing.

Regards, John
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Re: Finding Tachometer Circuit

Post by Green1 »

1: finding the tachometer lead. I need to tap into the tachometer wire and get at least 1.8V AC and 1.5 Hz or faster. If anyone can tip me off on where to look for the tach wire, preferably in the engine compartment rather than underdash, it would be much appreciated.
good question... mine apparently didn't do well enough and the tachometer sensor always sees the engine as running, even if it's not (ie, doesn't start, but the remote says it did... (it worked for the first week after install...)
2: Finding the door actuator lock/unlock wires. As the vehicle already has a remote for the doors I assume there must already be something installed somewhere.
as this is aftermarket it will be hard to say exactly, but look for wires coming out of the driver's door and tied in to the old remote locking module, worst case pull the door panel off and connect direct to the aftermarket actuator unit.
3: Does anyone know the current for the electronic rear gate switch? THe remote's module supplies 500mah so I assume I'll need to use a relay to connect it if I want to use the trunk unlock on the remote to unlock the gate.
I'd try connecting directly to the back of the "gate unlock" switch on the dash and try that first, if there isn't enough "oomph" to pop the lock then you can try a relay, but that should do it.
#1 is the most critical at this time as I have it working but it can't crank properly and won't run more than 8 seconds until it knows what the rpm's are doing.
one thing to note... picture how hard it is to start these vehicles at -30... now remember that your remote starter can't use the accelerator pedal, and won't ever crank for more than a couple seconds...
The remote starter is great, but it won't do anything useful for you at -30, you'll still have to work in manually at those temperatures.
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JMK
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Re: Finding Tachometer Circuit

Post by JMK »

Thanks. I was aware after trying to start it at -26 that no remote start will ever be able to do it on its own. The main intended purpose of the remote start is to use the cold weather function to start the vehicle for 8-20 minutes every 2 hours while we're in Bow Summit for the day skiing. It will run that cycle for up to 24 hrs. Hopefully that will work.

Otherwise for home starting for mornings, you may have some luck up to -10 or -15 if when you park the vehicle the night before you set the throttle to something like 1500 rpm, I guess only time will tell.

Because the Deli has no Glo Plug light, the module can be wired to wait 18 seconds after powering the ignition as a delay. I noted on the other posts where it was felt that that long of a delay may make it pointless.

The rear gate wire is 14 guage so it must be getting quite a kick to open that latch, it would appear the relay will be required.
and won't ever crank for more than a couple seconds...
It actually depends on what it's reading from the tachometer setting. You 'train' the remote as to the correct idle RPM and you can adjust how much it actually cranks.

Thanks for the comments. I think the success of getting the vehicle started is extremly dependant on making a real good tachometer connection. THere are various places you can make your connection, which I either can't find/or don't exist on a Diesel Deli (in total they are: negative side of injector, camshaft sensor, crankshaft sensor, or ECM). If ir reads too low, it will overcrank, reads too high, and it undercranks. I originally connected to a module on the manifold beside the injectors that has about 4 Volts AC. but it doesn't work for the remote start module. I'm thinking one of the wires coming of the injector pump is probably a suitable wire if I knew which one. The downloadable wiring diagram unfortunately isn't the best as you've probably experienced.
Last edited by JMK on Sat Jan 26, 2008 8:56 pm, edited 1 time in total.
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Re: Finding Tachometer Circuit

Post by Green1 »

if when you park the vehicle the night before you set the throttle to something like 1500 rpm
remember that engine revs are dependant on engine temperature, 1500rpm when you park is probably nothing useful when you go to start...

18 second delay is a big problem, might be good for a standard system, but we have a quick-glow system in the Delica, I know I need to shorten my delay somehow too because it's cold again by the time the starter tries.

If your device can take an input from a glow-plug light instead of a set delay you could probably wire something from the glow plug relays to substitute for the light (I've been thinking of wiring in my own glow plug light that way)
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JMK
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Re: Finding Tachometer Circuit

Post by JMK »

See my edit above about the number of cranks.

Yeah I think the idea of creating your own glow plug light is the best, and probably won't be all that hard to do. Luckily I've got a bunch of spare relays kicking around.

The other delay setting is 3 seconds, which was mainly intended for gas engines. Do you think that would be better for the Deli?

I've certainly been spoiled by the 24V starting system in the HDJ81 Land Cruiser that's our other current JDM. Now off-topic but this is definately worth a look anyway. It sold at auction in Japan on Dec 27. Bidding started on it at 700,000 Yen and it went for 1,480,000 yen
http://www.outbackimports.ca/landcruiser.php#HD-2963

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Green1
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Re: Finding Tachometer Circuit

Post by Green1 »

The other delay setting is 3 seconds, which was mainly intended for gas engines. Do you think that would be better for the Deli?
seems a little short to me, but I'm not sure... may have to take a stopwatch to it at some point, but I'm suspecting that in cold weather (when it actually matters) it's somewhere around 8-10 (just a guess)

beyond that... I was considering that I could always build my own delay circuit of some form to do the job...

Really I'm not planning on doing anything on that front until spring though, sounds like too much time fiddling around outdoors for this time of year, ESPECIALLY this week!
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Schwa
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Re: Finding Tachometer Circuit

Post by Schwa »

3 seconds sounds good if you're gonna be starting semi-warm (every 2 hours) but not good for the first-start-of-the-morning type start.

The tach gets a signal from the alternator, not sure of the voltage/frequency.
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JMK
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Re: Finding Tachometer Circuit

Post by JMK »

Thanks Eric,

I'll poke around the alternator and see if I can find an AC circuit, however it may be just providing a reference as it's not listed as one of the potential sources. THey list 'the negative side of injector', which I assume must apply to gas fuel injectors.

Given that it's probably not going to cold start anyway, maybe the 18 second delay is worthless. But then again, if it is starting every 2 hours, it probably doesn't matter if it's 18 or 3. At the moment it is wired for 18.

If anyone's interested because they wire up a remote as well, it may be useful to know it looks like you'll need 2 relays if you want to wire your back gate to unlock (or lock for that matter) from your keychain remote. THe dashboard switch closes 2 circuits when you press it.
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Re: Finding Tachometer Circuit

Post by EricN »

Another option for the rear gate lock is to pull the 2 wires out of the switch and just splice them into the wiring for your door locks. That way the hatch just locks and unlocks with the doors and if you want to get fancy you can use the "trunk unlock" circuit on the remote as an unlatching circuit by adding a strong actuater to the handle linkage. Only downside is the button on the dash gets disconnected but I have never had the desire to use it.
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JMK
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Re: Finding Tachometer Circuit

Post by JMK »

Thanks Eric.

That would be tempting as getting 2 relays onto that cramped wiring is a nightmare. Now as for that switch, here's something we did for travelling in Mexico as an antitheft device that worked real good in the '70's before the 'club':

This was for a gas vehicle that had an ignition coil, I wonder what the best circuit you could use in a diesel for this?

1: Take an innocous looking swith on your dashboard that is not in use, or you can hide a new switch in a secret location.

2: Wire the switch to the ground wire on the ignition coil so it breaks the circuit.

3: When you leave your vehicle unattended, throw the switch.

If someone tries to steal your car, of course they will never get it started. As most thieves are not going to lift your hood and run diagnostics on your ignition circuit, they'll be gone. And it's probable they are not going to say, "jeez, the car won't start, maybe I need to push this 'rear gate' switch to get it started!"

SO the rear gate switch, if made redundant, would be good for that. And if someone does manage to steal your vehicle and you were using this switch, you'll know they were on this forum! Somehow I don't think there are too many car thieves hanging out here however.

-WOn;t work of course if you're using the cold weather option on your remote though. In that case probably good to use a 'club'.
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