diesel swap

AVILES

New member
hi everyone, i did an engine swap on my 97 jeep wrangler, i swaped the om617 turbo diesel engine from a 83 300sd mercedes benz. i got most of it done i just need to do some wiring and get new driveshafts. but i have a question, does anybody know if i can connect the mercedes alternator as if it was the jeep's? in other words can the mercedes alternator work in the jeep or should i just mount the jeep's alternator on the mercedes engine. thanks everyone.
 

I would think either would be fine but I'd prob run the mercedes. Oh and start a build thread cause I'd love to see some pics.
 
My guess is, it would depend on the wiring and the diesels ECU's requirements. Compare the charging output from the Mercedes and the Jeep and see if the Jeeps output comes close to the Mercedes. Look the wiring as well, remember to keep it simple. Some alternators uses a 1 wire, 2 wire and a 3 wire configuration.
 
Good job on the swap. If I recall, that's the five cylinder engine with an aluminum head. If it has glow plugs I'd use the Mercedes alternator. Glow plugs pull a fair amount of current and the Jeep unit might not keep up. For cold weather also consider a bigger battery because if the engine cranks too slow it might not want to start. Those Mercedes diesels run FOREVER. I think what you picked is the perfect size and weight for the Jeep- good job. Can't wait to hear what you get for MPG... Keep us posted -John
 

thanks everyone, im going to use the original MB alternator, other people who have done that same swap seem to have used it, but i have another question. does anybody have a pcm pinout for a 97 jeep wrangler? im trying to reconnect some of the components back up like the oil pressure sending unit, the water temp sending unit, the fuel level sending unit and so on but i cant figure out what harnesses connect with what. thanks in advance for any help
 
tj780271-1.gif

POWERTRAIN CONTROL MODULE (A) C2 CAV CIRCUIT FUNCTION
A1 - -
A2 F12 18RD/LG FUSED IGNITION SWITCH OUTPUT (RUN/START)
A3 - -
A4 K167 18BR/YL SENSOR GROUND
A5 - -
A6 T41 18BR/LB PARK/NEUTRAL POSITION SWITCH SENSE
A7 K19 18GY IGNITION COIL DRIVER
A8 K24 18GY/BK CRANKSHAFT POSITION SENSOR SIGNAL
A9 - -
A10 K60 18YL/BK IDLE AIR CONTROL NO.2 DRIVER
A11 K40 18BR/WT IDLE AIR CONTROL NO.3 DRIVER
A12 K10 18DB/BR* POWER STEERING PRESSURE SWITCH SENSE
A13 - -
A14 - -
A15 K21 18BK/RD INTAKE AIR TEMPERATURE SENSOR SIGNAL
A16 K2 18TN/BK ENGINE COOLANT TEMPERATURE SENSOR SIGNAL
A17 K7 18OR 5 VOLT SUPPLY
A18 K44 18TN/YL CAMSHAFT POSITION SENSOR SIGNAL
A19 K39 18GY/RD IDLE AIR CONTROL NO.1 DRIVER
A20 K59 18VT/BK IDLE AIR CONTROL NO.4 DRIVER
A21 - -
A22 A14 14RD/WT FUSED B(+)
A23 K22 18OR/DB THROTTLE POSITION SENSOR SIGNAL
A24 K41 18BK/DG UPSTREAM HEATED OXYGEN SENSOR SIGNAL
A25 K141 18TN/WT DOWNSTREAM HEATED OXYGEN SENSOR SIGNAL
A26 - -
A27 K1 18DG/RD MANIFOLD ABSOLUTE PRESSURE SENSOR SIGNAL
A28 - -
A29 - -
A30 - -
A31 Z12 14BK/TN GROUND
A32 Z12 14BK/TN GROUND

tj780261-1.gif

POWERTRAIN CONTROL MODULE (C) C1 CAV CIRCUIT FUNCTION
C1 C13 18DB/OR A/C COMPRESSOR CLUTCH RELAY CONTROL (EARLY BUILD)
C1 C13 20DB/OR A/C COMPRESSOR CLUTCH RELAY CONTROL (LATE BUILD)
C2 - - (EARLY BUILD)
C2 C27 18DB/PK RADIATOR FAN RELAY COIL FEED (LATE BUILD)
C3 K51 18DB/YL AUTOMATIC SHUT DOWN RELAY CONTROL
C4 - -
C5 - -
C6 - -
C7 - -
C8 - -
C9 - -
C10 - -
C11 - -
C12 A142 18DG/OR AUTOMATIC SHUT DOWN RELAY OUTPUT
C12 A142 18DG/BK AUTOMATIC SHUT DOWN RELAY OUTPUT(LATE BUILD, W/O DRL AND ABS)
C13 - -
C14 - -
C15 K118 18PK/YL BATTERY TEMPERATURE SENSOR SIGNAL
C16 - -
C17 - -
C18 - -
C19 K31 18BR FUEL PUMP RELAY CONTROL
C20 K52 18PK/BK DUTY CYCLE EVAP/PURGE SOLENOID CONTROL
C21 - -
C22 C22 18DB/WT A/C SWITCH SENSE
C23 C90 18LG/DG A/C SWITCH OUTPUT
C24 K29 18WT/PK STOP LAMP SWITCH SENSE
C25 K72 18DG/OR GENERATOR FIELD SOURCE (+)
C26 K226 18DB/LG FUEL LEVEL SENSOR SIGNAL
C27 D21 18PK SCI TRANSMIT
C28 D2 18WT/BK CCD BUS(-)
C29 D20 18LG SCI RECEIVE
C30 D1 18VT/BR CCD BUS(+)
C31 - -
C32 - -


tj780281-1.gif

POWERTRAIN CONTROL MODULE (B) C3 CAV CIRCUIT FUNCTION
B1 - -
B2 - -
B3 - -
B4 K11 18WT/DB INJECTOR NO.1 DRIVER
B5 K13 18YL/WT INJECTOR NO.3 DRIVER
B6 K15 18PK/BK* INJECTOR NO.5 DRIVER
B7 - -
B8 - -
B9 - -
B10 K20 18DG GENERATOR FIELD DRIVER (-)
B11 T23 18OR/LG TORQUE CONVERTOR CLUTCH SOLENOID CONTROL
B12 K16 18LG/BK* INJECTOR NO.6 DRIVER
B13 - -
B14 - -
B15 K12 18TN INJECTOR NO.2 DRIVER
B16 K14 18LB/BR INJECTOR NO.4 DRIVER
B17 - -
B18 - -
B19 - -
B20 - -
B21 - -
B22 - -
B23 G60 18GY/YL OIL PRESSURE SENSOR SIGNAL
B24 - -
B25 - -
B26 - -
B27 G7 18WT/OR VEHICLE SPEED SENSOR SIGNAL
B28 - -
B29 - -
B30 - -
B31 K6 18VT/OR 5 VOLT SUPPLY
B32 - -
 

I too would like to know what type of fuel mileage you are getting. Also, ball park figure on your investment.
 
ok so i got it running already, i drove the jeep for a while today. i swaped the sending units for the water temp, the oil pressure from the original engine but now none of the gauges on the dash board are working. nothing else is connected to the computer but that and the volt meter and the fuel level. does anyone have an idea why it is not working?
 
Look on the right side of the engine compartment. Near where the Jeep starter was there should be two black heavy wires that share a common eyelet connector. These need to go to gnd. I have a Cummins 4bt in my 98 TJ, so our wiring harnesses are very similar due to the years. I had a similar gauge issue till I grounded those wires. As far as the alternator determine which is the signal wire, which is 12v reference, and the charging wire is obviously bigger. The sig and 12v ref will need to be cut and separated. Thats what I did on my Delco alt. and connect them to their respective terminals on your alt. As far as glow plugs go and alt. output it does not matter because the engine isn't running yet when the GP are on, they use battery voltage only. There isn't any ECU on a om617.
I have an extensive build thread over on 4btswaps.com I have the same username on that site. http://www.4btswaps.com/forum/showthread.php?1209-Jeep-TJ-and-a-4bt-diesel&highlight=
Let me know if I can help.
BTW if anybody is thinking about doing a diesel swap with the intention of having fuel savings pay for the swap don't fool yourself, this isn't a cheap swap.
 
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Another thing on mine I always have a check engine light.
 
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