Engine/Transmission (1998.5 - 2002) DTT Smart Controller and Exhaust Brake

[DavidC]

I was trying to finish the Exhaust Brake install and read a post on DTT's site from a person that he installed a relay on the TC lockup signal (Blue wire) from the smart controller so that the EB would be disabled if the lockup signal was lost. I installed the relay, ran the coil ground and was ready to connect the other side of the coil to the blue wire. To my amazement the relay energized with the truck sitting in the garage with nothing on. I checked the voltage and sure enough 12. 8V on the wire. This kind of tells me the lockup signal is there when the truck is parked. The trans. and controller work normally with the indicator lights and lockup working ok. Tried to call DTT with no answer, left an e-mail. Thought I would ask here. Does anybody have any experience with this one.



Dave

 

[Herman8r]

Dave--I would wait until Monday & talk to BILL K AT DDT as he is the man! He may be busy but he will find time to talk to you.



Herman

 

[DavidC]

Dave--I would wait until Monday & talk to BILL K AT DDT as he is the man! He may be busy but he will find time to talk to you.



Herman

Thanks for the reply. Looks like I do not have a choice except to wait for a reply to the email or call on Monday. I can get myself into the weirdest problems. If there is an answer to this I will post here for future reference as I do not think this is the first or last time someone needed this info.



Dave

 

[Regcabguy]

Desert Diesel Parts

You might be able to get a hold of Fred Swanson @ 623-910-9575. He's an authorized DTT dealer in your area. Really a good guy.

 

[DavidC]

OK, here is the skinny after talking to Bill at DTT. The exhaust Brake wiring that sends the +12VDC to the solenoid stays as it is installed. The ground wire for the solenoid ties into the lockup solenoid, not to the chasis ground. No need for the added relay. The signal for the lockup creates a ground when it initiates. The reason I had read the 12VDC on the lockup wire was because the voltage was going through the lockup solenoid but the computers were not calling for lockup (not grounded) so I essentially had an open circuit.



Dave

 

[Herman8r]

Dave--did you tap into the lock up wire on the DTT controller to activate the exhaust brake? If so what color was the wire?



Thanks, Herman

 

[DavidC]

Dave--did you tap into the lock up wire on the DTT controller to activate the exhaust brake? If so what color was the wire?



Thanks, Herman

Yes on the Smart Controller. The wire on the Controller is blue which then spliced into the orange/black to the trans. lockup solenoid. I essentially T'd off of that wire with a removable insulated spade connector. 1 male on the exhaust brake and 1 female T'd off the blue wire. This was so I could isolate the brake if need be. The system is now automatic and the light in the rocker switch comes on when the TC is locked showing the brake is active and waiting for the throttle to go to idle. When I get down to 30mph the brake deactivates and the light goes off until the next round.



Dave

 

[Herman8r]

Thanks for the info--is the blue wire a ground that also grounds the rocker switch? Do you have a wiring diagram? Sounds like a good idea.

Herman

 

[DavidC]

Thanks for the info--is the blue wire a ground that also grounds the rocker switch? Do you have a wiring diagram? Sounds like a good idea.

Herman

Take a look at this. On page 10 shows the wiring diagram for the jacobs brake. The green wire that it shows to Chassis ground is the wire you remove from the chasis and T into the Orange/Black which is also the Blue from the Smart Controller. Hope this helps.

http://www.jakebrake.com/service/pdf2/028536C.pdf



Dave