Oil pressure switch (12HT)

[Fey1]

Hello all,

Does anyone here know at what pressure the oil pressure switch switches at? I am looking to replace the one in my 12HT with one that reverse senses. In other words, the stock switch CLOSES when there is NO pressure and OPENS when there is pressure. In reality, this is UNSAFE because if the wire is disconnected or broken, the IDIC will assume that everything is okay and you loose the low pressure shut down.

I am building a new controller for my 12HT and will set it up for a switch the closes when the pressure is good. In that way, if the wires is broken or comes off, the controller will take that as a loss of pressure and shutdown the engine.

I understand generally why many sensors in older case used the backwards sense, but it is a stupid idea.

Cheers,
Michael

 

[David*BJ70]

Instead of the 3B and 2H who are led by EDIC, there is no oil pressure switch on the 12HT. Only a oil pressure sensor.

 

[Fey1]

Hmmmm. That's going to make shutdown on pressure fail rather difficult.

 

[Tapage]

Mechanical oil aftermaket gauge ..?

 

[db3]

I'm using a Holley Pressure Safety Switch P/N 12-810 , which has both NO and NC contacts, and switches at 5#. I also am using the Engine Watchdog TM1 to monitor both head temperature and low oil pressure. ENGINE WATCHDOG Audible Engine Overheating Alarm, Gauge & Sensor The unit works very well.

 

[roma042987]

Hmmmm. That's going to make shutdown on pressure fail rather difficult.

If that's what you want to do just add an aftermarket pressure switch and let it trigger a relay the grounds the shut down solenoid.

 

[Fey1]

Yeah, I'll have to go with the after market pressure switch. I'll have to tee it off from the pressure sender for the gauge.

The Engine Watchdog stuff looks good but it requires a normally closed switch, and is therefore intrinsically unsafe.

Like the IDIC on the 2H, I want a slight delay before shutting down the engine. My old 2H did not always pressure upon startup until after a few seconds. (especially when cold). A warning light will illuminate instantly when the pressure drops, but the engine will run for a few seconds. The system will have two timers - one when starting which will provide a longer delay, and one for running after starting with a much shorter delay. Probably over kill, but what the hell. What I would really like to do is install a pre-oiler system to ensure that everything has at least some oil before starting.

 

[hj 60]

If you can make it yourself maybe add a anti theft timer, I like how my HJ starts and then shuts off and I hope an occasional thief gets out after a few starts and stop, possibly in the middle of the road.
The system is very dangerous, when the wire is cut the edic does not notice and starts even without oil.



SWITCH ASSY, OIL PRESSURE
08.1980 - 02.1985= 8353014010
8353028030


SW-P1003
TOYOTA,SUZUKI,SUBARU,NISSAN,MITSUBISHI,MAZDA,KIA,HYUNDAI,DAEWOO,FORD 83530-10010,83530-10020,83530-12020,83530-14010,83530-14030,83530-28030,83530-30030,37820-73000,37820-79600,37820-80G01-000,37820-82000,37820-82001-000,37820-82002-000,37820-82001,42995-7000

HJ60 testing oil pressure switch, no pressure (engine off) is contact.
Test with air compressor if it switches off (so pressure means no connection),

HJ60 oil pressure switch cut open, small membrane with rubber O-ring and spring.
It was dirty with typical white electicity erosion and the membrane was pushed in and the metal plate was not making contact with the contact on the oil/engine side.
Like there was oil pressure even with engine off!

a wd40 straw will fit trough and might help cleaning it a bit:

original pictures and more from: hj60.freeforums.org • View topic - EDIC manual, oil pressure switch, relief valve

 

[Fey1]

For anti-theft, I have a number of systems in place that inhibit starting or running. Hidden kill switches, RFID proximity relays, and a few other things.

 

[db3]

What I would really like to do is install a pre-oiler system to ensure that everything has at least some oil before starting.

I had Pre-Luber pumps on all my vehicles at one time. The guy who designed them in the late 80's did so because he kept destroying the turbo on his Datsun pickup. The timer module could be set for both pre and shutdown lubing. The company changed hands several times, and I'm not sure if they are still around. If you are interested in a used one, let me know. I'm just across the bay in San Ramon.

 

[Fey1]

I had Pre-Luber pumps on all my vehicles at one time. The guy who designed them in the late 80's did so because he kept destroying the turbo on his Datsun pickup. The timer module could be set for both pre and shutdown lubing. The company changed hands several times, and I'm not sure if they are still around. If you are interested in a used one, let me know. I'm just across the bay in San Ramon.

I actually have an aircraft pre-lube system. Installing it requires more effort than I can afford at the moment. My big hurdle for this is where to tap back into the system. I'd like it to be before the oil filter. Pickup is easy enough - pull the pan weld a fitting on to it.

This is all something that should be considered to do now as my truck is down waiting for a turbo. I just don't have the cash / time / location to do such work.

 

[db3]

The original Pre-Luber used a 'T' at the pressure switch. Easy, but not the best. I am considering an oil filter bypass adapter. I think I saw one for my 1HZ engine, but don't know about the 12HT. As for the Engine Watchdog unit, I think the manufacturer would take issue with you calling them 'unsafe'. I think you meant Fail-safe.

 

[Fey1]

The original Pre-Luber used a 'T' at the pressure switch. Easy, but not the best. I am considering an oil filter bypass adapter. I think I saw one for my 1HZ engine, but don't know about the 12HT. As for the Engine Watchdog unit, I think the manufacturer would take issue with you calling them 'unsafe'. I think you meant Fail-safe.

Yeah, I am thinking of a puck by-pass adapter at the filter.

If the watchdog uses the original pressure switch, it is unsafe. They should be normally closed and open on pressure.

 

[Terry2can]

Hello all,

Does anyone here know at what pressure the oil pressure switch switches at? I am looking to replace the one in my 12HT with one that reverse senses. In other words, the stock switch CLOSES when there is NO pressure and OPENS when there is pressure. In reality, this is UNSAFE because if the wire is disconnected or broken, the IDIC will assume that everything is okay and you loose the low pressure shut down.

I am building a new controller for my 12HT and will set it up for a switch the closes when the pressure is good. In that way, if the wires is broken or comes off, the controller will take that as a loss of pressure and shutdown the engine.

I understand generally why many sensors in older case used the backwards sense, but it is a stupid idea.

Cheers,
Michael

Gday Mate have you got some photos to share as I’m doing mine atm.
Cheers Terry