Auto shutdown based on EGT up and running!

[Archive]

I just finished installing an ISSPRO turbo temp monitor on my '98. 5 24v. This is a really neat product - it monitors a post-turbo thermocouple (it can daisy chain off of an existing one if you mounted your's post-turbo) and doesn't let the engine shut down until the EGT is below a set temp (comes preset at 300 degrees and you can adjust it from there). It was a little tricky getting it hooked up as Isspro doesn't have vehicle specific instructions. At first I had it wired into only one of the ignition wires and when I turned off the truck ABS and Air bag alarms went off (they are fed off of a different bus). So I had to design a circuit with a relay and a diode to power up the second bus. It now works GREAT!! An added benefit is that I put an exhaust brake on last weekend and now I can start the truck, turn on the exhaust brake, wait about 15 seconds for the post-turbo EGT to get over 300 degrees and then turn off the ignition and pull the key, lock the doors and walk away for it to warm up at idle (takes about 4 minutes to come up to full operating temp in 30 degree weather!) (Don't forget to leave the truck in neutral) When I want to shut down I just turn off my exhaust brake, set the parking brake, turn the truck off and walk away. She turns herself off when she's cool!! I also installed a disable switch on the right side of the steering column right behind the ignition switch for an emergency shut down - turn off the ignition then hit the switch. I'm attaching pictures of the install plus the schematic that I drew. This schematic is out of the factory service manual on page 8W-12-6 (in the 98 manual) - it's the very first schematic in the 8W-12 junction block so you can compare to the schematic and wiring colors in your truck. This setup is much better than the diesel life saver through genos (it's just a timer) and it's cheaper too! Here are the total costs:

(I bought most of the stuff through diesel injection service except for the relays, wires, fuse holders, etc. which I bought through a local electronics supply shop and these prices do not include shipping)
ISSpro turbo temp monitor (R4130) $116. 64
K type thermocouple (R658) $27. 34
Lead wires (R660-10) $10. 29
R51-1D40-12F 40A-12VDC relay $5. 72
NTE5983 100V 40A Rectifier $5. 00
small plastic project case $2. 00
(to house rectifier)
2 automotive style fuse holders $1. 84
20A switch $5. 00
2 20A fuses (had on hand) ~$1. 00
10 gauge and 14 gauge wire $4. 00
--------
$178. 83

-Steve St. Laurent - President of the Great Lakes TDR
'98 Quad Cab Long Bed (CMNSPWR), 4x4, ISB, 5sp, 4. 10 LSD, Prime-loc remote fuel filter,
boost & pyro gauges, TST Powermax, muffler eliminator, 5" chrome tip, BD Exhaust Brake,
Isspro turbo temp monitor, Permatech spray in liner, Grizzly stainless nerf bars,
Stull SS grill & bumper inserts, Front Draw-Tite receiver, BFG 285/75R16 AT KO's
http://my. voyager.net/stevest

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[This message has been edited by Steve St. Laurent (edited 03-29-2000). ]

[This message has been edited by Steve St. Laurent (edited 03-31-2000). ]

[This message has been edited by Steve St. Laurent (edited 07-20-2000). ]

 

[Archive]

excellent steve , i purchased the same thing from DIS , haven't recieved it yet , but i will scare up the parts and be ready , this will probably get me off my butt to wire the lights to my gauges too. this is the bestest board .

doc welcome aboard , come over to the "DARK SIDE" its so much more fun being BOMBed !! #ad
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Great documentation, bravo!

Looks like the 99's manual is the same, I was a bit confused until I realized you had written over the A31 wire.

When you wrote the first posting on my other thread, I had considered using the module to drive two relays that would therefore maintain the independance between the two circuits and allow me to run low current wires from the relays to the controller &/or cutout switch.

Are you driving that relay all the time(when the engine is over 300), or only when the keys are removed?

 

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All the time but with the recitifier in there it can't back feed.

-Steve

 

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Steve,
Thanks for the reply,

I was thinking of using the power outlet from inside the cab which is already fused to 20A. Tapping that and feeding your circuit, see any risk in that?

[This message has been edited by David_VT (edited 03-30-2000). ]

 

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Yes there is. You have two circuits that are being fed 12v - one is 20a and one is 15a. That's a total potential draw of 35a to feed both circuits. That's why I went to the post in the underhood fuse box that's protected by a 140a fuse. I connected both 12v wires directly to that post (2 wires going to the engine compartment). There is a rubber boot that is in the firewall to the left of the clutch pedal that you can pierce to send the wire through - it's very easy and quick.

-Steve

 

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Good point

 

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I had to change out the 15a fuse to a 20a fuse - I blew the 15a yesterday. I've updated the message and the drawing at the top of this post to reflect that. I thought a 15a would drive everything but after looking closer at junction block 8W12-2 and circuit breaker 8W-12-17 (a 20a circuit breaker that is fed from the 14 gauge Black/Orange wire) I see that 20a's is necessary. The 14 gauge wire (the weakest link in the line) should handle 20a no problem as that's what the factory is feeding that block with. I wanted to keep the fuses down to the smallest size possible to protect everything as best as I could. Sorry about the mistake.

-Steve

 

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Sending this back up to the top as several people have been asking about it lately. One addendum - the 2nd circuit, the one on the black and orange wire will occasionally (it's only happened twice) blow the 20a fuse on that line. I've changed that fuse out to a 25a now and haven't blown any. The 14ga wire should be able to handle 25a, I normally use 20a as my limit on a 14ga wire but Dodge used 14 on that line so it must be able to handle it. I'm also going to add a parking brake interconnect soon (waiting for DavidVT and MCrossley to finish their project to see how they did it first) so that the circuit isn't powered up during normal operation of the truck.

-Steve

 

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Well, here I am a month later and the 25a fuse is doing great. I feel the wires, diode, and relay regularly to check for heat - none found. Haven't blown a fuse yet with the 25a in there - I'm 99. 9999% sure that it's just a very momentary spike above 15a that was blowing them. Still loving my shutdown module!!

-Steve

 

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steve , thanks for bringing it back to the top , maybe i'll connect it up , i just printed the schematic , now to get the parts , i've had the unit since march ...

 

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Steve,

The ISSPRO Turbo Temperature Monitor is only rated for 15 amps. I'm going to use the monitor to control 2, 30 amp relays, for the ignition circuits.

2001 ETH/DEE...

 

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Steve,
As I mentioned in my email, I've had little time to proceed with our module. MCrossley has the prototype.

One thing we also did was to use the start signal (yellow I think) to open the circuit which is held open by the key switch but closed by yours and our circuits. The thinking was that Dodge must be killing that circuit during start for a reason and I did not want a restart on a warm engine to allow it to close during the start cycle.

As I recall, the parking brake switch is just a ground so we were going to tie into it and isolate with diodes to prevent any 'backtalk'. The hot side of that relay would be from the cool down module, effectively isolating the cool down module from the normal operation of the truck unless the parking brake is pressed. That should decrease the load on the fuses you are using since their usage will only occur when the system is hot and the brake is depressed.

I was worried about the more upscale trucks with the OEM alarms and how the brake circuit being tapped might effect the alarm. This might be unfounded concern but fell into the better safe than sorry bucket (re: the diodes).

 

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jcbrown, my data sheet shows 15 amps as well. When I designed that circuit I was talking with the Isspro engineer responsible for that product extensively. I don't remember exactly what he said at that time (I have a phone call into him to verify this) but he said that it is rated much higher than 15a. They had changed the unit once production was under way to increase it's load capability and hadn't reprinted the documentation. He said 20a was no problem at all (I think he said it was rated for between 30a-40a) - I'll post the exact number once I speak with him.

David, I had considered that but the only time that that situation could occur would be if the post-turbo EGT is over 300 degrees at start time. The only time that could happen is if you did an emergency shutdown (using the switch on the column) and then restarted very soon thereafter. I like the parking brake switch idea but was waiting for you guys to figure that part out before I dove into it. Maybe I'll dig into the manuals and check that out myself. I'm going to be putting together an article for the TDR on this product and install for issue #30 and will have it done before then. If I'm missing something here let me know.

Thanks,
Steve

 

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I got a call back today from Bill Larsen of Isspro who is the engineer I worked with there while designing my circuit and the guy responsible for the shutdown monitor right now. He had to go look it up as he didn't recall off of the top of his head what the module was rated at. He looked at the schematics and his data and he says it's good to 30 amps on a 12v system which was what I thought he had said back then. There was a production change before it ever went out to the public and the data sheet was never changed.

-Steve

 

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Steve, I know this is an old post -- hope you're still looking at it now and then.

Do you know if this device will work with an Auto Meter thermocouple? I don't know if it's grounded/ungrounded (or if it matters), but it is a "Type-K" (whatever that means).

What brand thermocouple are you using?
Anybody using this with something other than a Isspro t-couple?

 

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The type means what material the two TC leads are made of. For Type K the + side is Ni-Cr (Chromel), and the - side is Ni-Al (Alumel). If I understand the way thermocouples work, you should not have any difference in reading as long as the TC types are the same. If the unit is using type T for instance, you couldn't use your AutoMeter probe. Looking at the installation instructions, it is a type K so you should be alright.

[This message has been edited by jwgary (edited 07-21-2000). ]

 

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Steve,
I've been reviewing your drawing and I have a question about it.

Why does the relay connect to the terminal labeled "Lamp"? Is this a mistake (on the drawing)? Or do I not understand how this circuit works?

My understanding was: You need to energize two busses based on the signal coming from the Isspro box. The box itself can handle the current draw from one of the busses, but not both. So, you used the signal from the box to power one bus and close a relay that powered the other bus. Is that about it? Or have I missed something?

What's that "Lamp" signal do?

 

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The lamp signal is simply there originally to light an led when the temp is over 300. I used that to fire the relay that powers the 2nd circuit, the lamp position switches to ground when over 300 degrees.

-Steve

 

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Thanks Steve, That explains it (I thought that lead should go to ground).

Do you know if this box will work with an Auto Meter thermocouple? It's a type-K, but I don'w know if it's grounded or ungrounded.


[This message has been edited by Kyle (edited 07-23-2000). ]