Medium and Heavy Trucks
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k. TH297145. BACKGROUNG IS AS FOLLOWS. NO START LAST FAFF. NO FUEL PRESSURE. INSTALLED NEW PUMP, WORKED FINE TILL NOW. CAN PRIME HAND PUMP HARD AD DOESNT WEAKEN EVEN AFTER CRANKING. INSTALLED NEW CAM SENSOR AND GAPPED. SAME ISSUE. NOT EVEN A PUFF OF EXHAUST. CIRCUT BREAKER FOR ECM IS GOOD. SCANNER IS OUT BEING SERVICED. DONT HAVE SCHEMATICS. PROCESSOR??
NONE OTHER THAN THOSE NORMAL TO KOEO.
THE LOW PRESSURE PUMP , JUST DOWNSTREAM FROM THE HAND PUMP
ONLY RELATED ONE I SEE IS A BREAKER UNDER THE PANEL FOR THE ECM, HAS POWER. DONT KNOW WHICH PINS ON THE PROCESSOR TO CHECK POWER AND GROUNDS
TKS WILL SCOPE IT OUT
IF IM FOLLOWING THIS RIGHT, FUSE 5 IS KEY ON IGN POWER TO THE PROCESSOR, PIN 24. FUSE 12 IS KEY ON POWER THE THE PROCESSOR RELAY. AND PIN 25 GROUNGE THE REYAY TO SUPPLY POWER TO 21 22 41. IF EVERYTHING IS KOSHER WITH THE WIRING, KEY ON SHOULD POWER 21 22 41 WITHOUT CRANKING, CORRECT?
FUSE 12? IM SHOWING 11. BAD ON MY PRINT OR DID YOU FAT FINGER THE KEYBOARD? P.S. LIKE I DO...
TRUCK AT COSTOMERS SHED. IM AT THE SHOP NOW, WILL CHECK AGAIN AM. IVE GOT ALL BREAKERS. NONE TRIPPED , ALL HAD PRIMARY POWER BUT ILL FUSED JUMP THOSE 2 TO TEST NOW THAT I KNOW WHAT TO LOOK FOR. TKS
harnesses are night and day different, can verify relay opperation, single wire directly to proseccor in place of 21 22 41. what i cant vertfy is power from fuse 5 ( if it even relevent to the 95 model) harness off the processor power only to one 10 gauge wire. would where you work have a 95 schematic?p.s. im not a cheepskate on bonuses
go ahead and look. as far as i can tell the computers are 95-96 only.im pretty sure its the processor. ive established a good relay but would like to check secondary power and grounds. if i can get a processor ordered by tues ill be in good shape.
Just checking with you again on this ! All the fuses in battery box are ok? And also did you say the warn engine goes on and then out as a bulb check at key on ?
primer bulb stays hard even after cranking, fuses are all good and constant battery power is present at the relay. your diagram for the 98 harness shows fuse 5 as secondary power to the processor. if i unplug the processor i only have power on the single circut # XXXXX comes from the relay. i have no secondary power. that is where i guess i will need the 95 specific diagiram to chech the power and grounds. my wiring #'s are totally different
got a 9004 bulb with alligator clips for high amp tests. wire to batteries ok. with the relay unhooked , key offthere is power on one big wire, go to key on, power on one big and one small, plug in relay and brings up power on other big wire to the processor.. key off drops it. possable ground issue from processor to batteries but dont know which processor pin is master ground. there is one 10 gauge white on the processor connector. wondering if that is the ground.
havent been back at it. possably later today. how and where do they usially ground the processor?
verified ground at processor plug with headlight from hot at processor wire. gona order processor. both are # XXXXX so im assuming the same as you. if its ok im gona leave this open with you till its running. thanks brian
Ok ! Let me know how it goes !Good luck !
finnaly got it but what a %ucked up deal. put in a idm and it took right off. fixed huh....not. changed the fuel filter and wouldnt go, air right.... not. bled and bled some more, ok what happened to the new idm? unhooked computer. hit power in with a test lite, good. at the relay out, good, at relay in, good. hit relay in with 9004 bulb, good. out, nothing ???? tried again after i put test leads back on bulb because they fell off and had power both sides??? screw around for a while and realized that when i put the leads back on that im now on the low beam (less amp draw). the amp draw on the processor is enough to drop the relay out, like "high beam" but the relay would stay in on the "low beam" draw. checked power at processor in with low amp draw, good. pluged in processot and back probed connector, nothing. hit relay with screwdriver and had power and started. bang on relay for awile and it lost power again, bang on relay for awile again and ipower came back and started. freeking intermittent relay. wont trust testing one again, im just gona replace it on a no start before i do anything else. cant get one aftermarket and my ihc dealer said they only sell about 2 a year. out of stock, special order for friday. hope yard takes processor back??? thanks for the help and the diagirams