EDIC Relay Oil Pressure Timer Repair

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rockcrawler

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Common problem so I thought I'd post the fix.
From what I have seen most EDIC relays use the same system for the timer although they may be a different board.

This is my BJ40 12V EDIC relay.
The capacitor circled is set up as a timer. As it ages its capacitance decreases causing the oil pressure delay time to become shorter.

Timer is reset when starter is engaged. There is no delay in turning the fuel supply off once the motor is running (after timer delay has expired) should oil pressure drop to low.

Replace capacitor to fix the bug.
 
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WOW! Did you read my posts in the "Is that normal" thread??

I was just asking around for hints as my 2H shuts off 8 seconds after starting when it's been sitting for awhile. I'm suspecting something wrong with either EDIC relay, low oil press. switch or, worst case scenario, oil pump.

If I understand correctly, the delay before shutting the engine off for low oil pressure on start-up should be 15 sec. but is decreasing when aging. So replacing that simple capacitor would reset it to it's original 15 sec duration, resolving my problem in the process...

Does that sound about right??

Thanks a bunch!
 
Henry James the 47th said:
Well done.

Do you have the specs. on that capacitor? A link to a source for a replacement capacitor?
Click to expand...

On my 12V EDIC, 330uF 16V, just run of the mill, you'll be able to get that anywhere. For 24V EDIC it may be a different value, but again just a common type.
But do check your particular EDIC for the value, I don't know if they used different values on others, depends on the resistor in front of it.
Get a 105°C rated cap, they will last longer.
 
To test EDIC relay/timer outside your vehicle:

Connect Negative to E

Connect Positive to IG (click - Relay 2 Down)

Connect Negative to OIL (click - Relay 2 Up)

Touch ST (2 seconds) with Positive (click - Relay 1 & 2 Down) and let go (click - Relay 1 Up). Count seconds until Relay 2 resets (click - Relay 2 Up).

To test low oil pressure cutoff function:

Remove Negative from OIL, Relay 2 should click immediately (Relay 2 Down).
(having Negative on OIL = Low Oil Pressure)

At least that's how I think it goes from memory.

Edit: should have written this down. Just checked it on my spare relay, correct now.

Edit 27 Oct 09: Multiple alligator jumper leads must be used for this test. Unless otherwise stated, jumpers stay on connector terminals through the procedure. Thought I'd point this out.
Thanks to Tom for making this clearer in his BJ42 FCR diag post.
https://forum.ih8mud.com/diesel-tec...rol-relay-woes-please-help-2.html#post4911649
 
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Thanks Alex!!! This thread has answered questions that were buzzing around inside my head too.

:beer::beer:
 
Excellent - thanks for posting up that diagnostic test. I had that test in my old 2H engine manual, which I sold :doh: when I got a 1886 2H engine along a newer manual. The late 2H manual does not have that test for the fuel control relay.

It's a bit academic for me as my truck has the pneumatically-operated injector pump, but it's great info for the forum.:clap:
 
No problem guys.
By the way I have revised the post on the diagnostics, so if you had copied it earlier for your reference then please re-copy it as there was a couple of errors in it, also I have made it clearer.
 
Mucho Gracias!!!

rockcrawler said:
To test EDIC/timer outside your vehicle:

Connect Negative to E

Connect Positive to IG (click - Right relay)

Connect Negative to OIL (click - Right relay)

Touch ST with Positive (click - Left relay) and let go. Count seconds until Right relay resets.

To test low oil pressure cutoff function:

Remove Negative from OIL, Right relay should click immediately.
(having Negative on OIL = Low Oil Pressure)

At least that's how I think it goes from memory.

Edit: should have written this down. Just checked it on my spare relay, correct now.
Click to expand...

WOW! This is great info! Thanks a lot man! Really!

There's just one thing I'm not sure about in the testing procedures. Should I connect all the E, IG, OIL and touch ST simultaneously? I suppose so, to replicate actual engine starting conditions.

Anyway, again, great thread! Thanks for posting it! :clap::clap:
 
Justcruzin said:
WOW! This is great info! Thanks a lot man! Really!

There's just one thing I'm not sure about in the testing procedures. Should I connect all the E, IG, OIL and touch ST simultaneously? I suppose so, to replicate actual engine starting conditions.

Anyway, again, great thread! Thanks for posting it! :clap::clap:
Click to expand...

Yes that's right. By connect I mean using alligator jumper leads onto the terminals from your supply. The test only draws a few milliamps. Use 14V for a 12V relay if you want to get an accurate count on the seconds.
 
You know if someone were to want to make a living repairing electronics and all they did was replace capacitors, they'd probably do alright :lol:
 
Ah I see, my HJ 45 always shuts itself off straight away on cold startup, so this is a big help. Just a note, the fuel control relay that is on the HJ 45/ BJ 40 are a little different to the BJ 42/ HJ47 relays, different pin outs in the plug for a start.
 
Nice to see what the relay looks like inside. Mine is clicking like mad and making the engine jump of and on constantly. I disabled the edic arm for now and dump the clutch just enough to kill the engine. Other then perhaps a electrical connection issue to the relay, what else would cause the relay to click madly when exceperating? Seems not to do it when decelerating much.
 
I do not regret doing what I did, but had I known about this, there's a very good chance I would not have ditched my EDIC system.

This is amazing. "Well done" is an understatement.
 
haryv said:
Nice to see what the relay looks like inside. Mine is clicking like mad and making the engine jump of and on constantly. I disabled the edic arm for now and dump the clutch just enough to kill the engine. Other then perhaps a electrical connection issue to the relay, what else would cause the relay to click madly when exceperating? Seems not to do it when decelerating much.
Click to expand...

I would try replacing the cap. Let me know if the situation changes after that but you still have problems.
 
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