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Re: Wiring a 3406E up to a truck that had 3406C peec

Hope I’ve posted this in the correct place! I am trying to help a friend use a 1996 Peterbilt 379 running gear (1996 Caterpillar 3406e 5EK version engine) with a 2005 Peterbilt 379 cab/sleeper combination that was wired for the Cummins ISX type engine. I checked the schematics and it looks like this is doable fairly easily with a few wiring changes and minor parts substitutions. I am just curious about any special considerations for the Caterpillar ECM wiring, we are planning on using the J1587 and J1922 data links but not the J1939 data link as it apparently was not used originally. This vehicle is registered as a 1996 Peterbilt, any suggestions or comments are appreciated.

Super Contributor

Re: Wiring a 3406E up to a truck that had 3406C peec

Cat didn't build the truck. They only supplied the engine. You'll need to go to the truck manufacturer/dealer for a schematic of the truck wiring.
New member

Re: Wiring a 3406E up to a truck that had 3406C peec

I did the same thing incoverted it to a 3406e to figure the wire numbers out I need the diagram for the peec side at firewall
New member

Re: Wiring a 3406E up to a truck that had 3406C peec

Hi do you have a link I'm looking for a wireing schematic at the firewall for ecm of a 3406c peec from a 93 378
Super Contributor

Re: Wiring a 3406E up to a truck that had 3406C peec

Jakes work depending on the way they are programmed. They automatically turn off at 1000 RPM and won't work with the truck not moving unless programmed to "manual". I wouldn't take the brake and clutch switches out of the circuit as you need those for the cruise control also. You'll need Cat ET to T/S the speedometer and tachometer issue. There is a speedometer test and tachometer test in ET. The tach head needs to be set for 113 pulses per revolution. The speedometer head needs to be set for 30000 pulses per mile. You'll also need to program the correct pulses per mile for your tire size and rear end ratio. Your local Cat dealer can probably go through the parameters with you and run the tests on the speedo and tach. Have them update the engine software also.
Contributor

Re: Wiring a 3406E up to a truck that had 3406C peec

Thanks Dave for all the help i got hte truck running now ive got issues first got the jake hooked up like you said and i have nothing im thinking of just takingthe clutch and service brake and tieing them right to a common out of the ecm to bypass the switches all together is the a good or bad thing

 

second tachometer am i missing something hooked it up and it dont work signal negative to signal negative on ecm and same with the positive is there something im missing maybe like a 12v out of the ecm

 

Third Speedometer hooked up the way you said even changed the sensor on the transmission and it does nothing any help with these three would help me greatly cause ive been beating my head against the wall trying to figure this out

 

Thanks again

 Mike Stotler    

Super Contributor

Re: Wiring a 3406E up to a truck that had 3406C peec

NO, you cannot tie in to the wiring to the oil pressure and coolant temp sensors. Either install senders for your gauges or buy a Cat dash display.
Contributor

Re: Wiring a 3406E up to a truck that had 3406C peec

On the clucth fan could i just hook it up to the 2 wires already coming out of the cab from my fan switch i have. With me being heavy i normally just let the fan run espesially with all the mountians i pull.

Contributor

Re: Wiring a 3406E up to a truck that had 3406C peec

Thanks Dave for my engine temp and oil pressure could i just tie in to the wiring before the sensors and just a run a wiring into the cab to the temp gauge and the oil gauge after 4 hours of tracing and checking wiring all im waiting on is the new TPS and checking to see if i could just splice into the wiring before the sensors cause i cant seem to find  pin on the out going to the cab for the oil pressure and engine temp.

 

 

Thanks in advance for all the help you have given me

Mike Stotler

Super Contributor

Re: Wiring a 3406E up to a truck that had 3406C peec

The oil pressure and coolant temperature gauges are connected to separate sensors from the engine electronics. Another option is the electronic dash display which is connected to the engine data link. Engine brake has one wire for the low setting, one for medium and both together for high. Connecting those wires through a switch to battery negative enables engine brake. You just need a new 3 position dash switch for the engine brake, along with the on-off switch.