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6.5L Diesel Engine Discuss the 6.5 GM diesel engine & associated components. Automatic transmission questions & problems belong in the 4L80/85 - 4L60E - 6L90 Transmission Forum

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Old 12-13-2014, 11:36 PM   #81 (permalink)
VanBoy
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Okay, silly question.....the fuse holder pictured to the "left" of the buss bar, is that the 10amp fuse that powers the lift pump relay in the diagram? If not, where is that 10amp fuse located (fuse panel inside cab?)......other location?

I don't recall if my LP runs when cranking.....I tried the in "D" (drive) and turned to start and don't recall hearing anything when I did that test way back when....

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1990 Ford E-350 7.3L IDI Club Wagon, 3.54LS x2
1994 Chevrolet C2500 6.5L TD, 3.42
1981 VW Rabbit Pickup 1.6L N/A x2
1978 VW Rabbit 1.5L N/A

================================================== ==
140amp 1996 alt. May 2016 / HO Water pump, Fan Clutch (used OEM), Crank Pulley-Aug 2015 /Stanadyne PMD installed 6/13 replaced- reinstalled D-Tech ,Soot Trap Delete Jan 18, 2014 / Heath TurboMaster Dec 22, 2013 / New OPS (BWD), OPS Relay mod,
black Stanadyne PMD w/ #5-June 2013 / Dorman relocation kit, D-Tech PMD to bumper, #9 resistor- Jan 2013 / Carter Lift Pump, P74143 10-15psi, 32gph- Dec 2012 / Brought home Dec 17, 2012

Other then that, the Chevy is STOCK.

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Old 12-13-2014, 11:49 PM   #82 (permalink)
kerrye
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I don't know but my key won't turn to crank when the transmission is in D.

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Old 12-13-2014, 11:51 PM   #83 (permalink)
Freddyack
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Safety lock out to keep from moving the truck during cranking.
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Old 12-14-2014, 11:42 AM   #84 (permalink)
VanBoy
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Why do I distinctly recall some members here on this site have posted they fill their fuel filter by putting said vehicle in D and "trying" to start the vehicle??? Some have stated that it activates their LP and they fill it by this method???

I tried it this morning... I got the gauges to move a bit trying to go to 'crank'. But I didn't hear anything and I know what my LP sounds like. One odd observation, my oil pressure was below 40 even after about 2 mim or so of running. Plus I had to bump the accelerator a bit to get t smooth out....odd. I'm damned sure 40psi is not right. Must be my OPS going out..... I'll have to probe around under the hood and use that diagnostic checklist to find out if the LP run feature while cranking works on my truck.....
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1999 Ford E-350 7.3L Power Stroke Club Wagon, 3.55
1990 Ford E-350 7.3L IDI Club Wagon, 3.54LS x2
1994 Chevrolet C2500 6.5L TD, 3.42
1981 VW Rabbit Pickup 1.6L N/A x2
1978 VW Rabbit 1.5L N/A

================================================== ==
140amp 1996 alt. May 2016 / HO Water pump, Fan Clutch (used OEM), Crank Pulley-Aug 2015 /Stanadyne PMD installed 6/13 replaced- reinstalled D-Tech ,Soot Trap Delete Jan 18, 2014 / Heath TurboMaster Dec 22, 2013 / New OPS (BWD), OPS Relay mod,
black Stanadyne PMD w/ #5-June 2013 / Dorman relocation kit, D-Tech PMD to bumper, #9 resistor- Jan 2013 / Carter Lift Pump, P74143 10-15psi, 32gph- Dec 2012 / Brought home Dec 17, 2012

Other then that, the Chevy is STOCK.

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Old 12-14-2014, 12:09 PM   #85 (permalink)
kerrye
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Quote:
Originally Posted by VanBoy View Post
Why do I distinctly recall some members here on this site have posted they fill their fuel filter by putting said vehicle in D and "trying" to start the vehicle??? Some have stated that it activates their LP and they fill it by this method???

I tried it this morning... I got the gauges to move a bit trying to go to 'crank'. But I didn't hear anything and I know what my LP sounds like. One odd observation, my oil pressure was below 40 even after about 2 mim or so of running. Plus I had to bump the accelerator a bit to get t smooth out....odd. I'm damned sure 40psi is not right. Must be my OPS going out..... I'll have to probe around under the hood and use that diagnostic checklist to find out if the LP run feature while cranking works on my truck.....
I've read that on here too. That's why I wrote what I did. It doesn't work for the reason Freddy noted. Just check the voltage at pin G at the OBDI connecter just to the right of the hood latch handle to check if the LP is getting power.
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Old 12-14-2014, 12:12 PM   #86 (permalink)
Freddyack
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IIRC filling their fuel filter by putting said vehicle in D and turning the key on works in OBDII trucks.
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Old 12-14-2014, 12:26 PM   #87 (permalink)
kerrye
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Somewhere someone claims you can do it on the OBDI by cranking in D. They probably thought that even though the neutral safety switch would stop the starter from operating, that the connection would still be made to the LP. However, there is some kind of physical barrier in the key switch which stops it from turning to crank in D. It's not like other vehicles where you can physically move the switch to crank, but nothing happens.
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Old 12-14-2014, 12:58 PM   #88 (permalink)
Glagulator
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A 95 will "CRANK" but no starter function in any gear other than park/neutral and is OBD1.
Pre-95 will not, there is a mechanical park/neutral lockout as well as the electrical one.
Post 95 function the same as 95 but are OBD2.
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96 SUBURBAN K2500 wife's truck 210k+ mi. orig. motor & trans, 3.73...
95 C2500 Suburban 6.5td HO w/p, timing set, HB & pulley, all rubber hoses, modded engine & main harness, converted to OBD2, PMD to bumper...
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Last edited by Glagulator; 12-14-2014 at 01:01 PM.
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Old 12-14-2014, 01:02 PM   #89 (permalink)
Freddyack
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Quote:
Originally Posted by Glagulator View Post
A 95 will "CRANK" but no starter function in any gear other than park/neutral and is OBD1.
Pre-95 will not, there is a mechanical park/neutral lockout as well as the electrical one.
Post 95 function the same as 95 but are OBD2.
Now we know for sure
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Old 12-14-2014, 07:38 PM   #90 (permalink)
HeavyChevy95
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"Somewhere, somebody claimed" would most likely be me. Seems the '95 model was the "red headed step child" caught in the middle of corp developement and EPA mandates so few bothered to take the time necessary to completely understand them, then as now SOSDD really.
If theres one thing Ive learned here at DP, that is EACH model year has its owns subtleties so what may apply one year may not necessarily apply to all.


ELECTRICAL TROUBLESHOOTING 101: Know how the system or circuit is supposed to work.


Quote:
Originally Posted by Glagulator View Post
A 95 will "CRANK" but no starter function in any gear other than park/neutral and is OBD1.
Pre-95 will not, there is a mechanical park/neutral lockout as well as the electrical one.
Post 95 function the same as 95 but are OBD2.
Not an automotive authority and certainly not alot of experience with pre or post '95 models however I can only confirm that on my '95 C3500 model which I do have some intimate knowledge of, with gear selector in "D" and ignition switch in the "Crank" position will ACTIVATE the lift pump while by-passing the starter motor (not engaged)..

I've used that method when I had a helping hand around to work the ignition switch so I could remain under the hood to observe.

With that said.. It was only later that I learned the much prefer LPR jumper method I routinely employ now. As it turns out, it works on all 6.5TD C/K Trucks ('92-'02) SO long as theres nothing wrong with the LPR electrical circuit or wiring..
No need to find an alternative fused 12vt power source.
No need to remembering which DLC is the "Fuel Pump Test Terminal."
No need to rush back and forth from under hood to cab to DLC to turn on/off.
No need in hunting down a female spade connector somewhere in the mess of wires behind the Underhood Fuse/Relay Center.. book all that..

With a simple paperclip, your in full 100% positive control of the lift pump s'ituation while still free to work on, further diagnose, and/or observe things right from under the hood.


The '95 model ushered in the Underhood Fuse/Relay Center. Before that relays where scattered on the firewall in weather proof housings that make identifying the LPR a slight challenge if things have been replaced and/or shuffled 'round a bit.
And repeatedly opening the brittle plastic weatherproof housing to gain access without breaking the locking tabs off, good luck with that. Know that if it does occur, its easily remedied with a 6-8" zip tie.. A fellow DP member showed me that, maybe he'll read this and post a pic..



Figure 1- Jumper installed in empty LPR receptacle of post '94 6.5 Turbo Diesel's Underhood Fuse/Relay Center. Note orientation..








Pre-Underhood Non "Convenience" Centers. BTW, thats NOT a LPR, not enough wires..


Im certain someone here has a picture of the LPR receptacle with the relay removed..

FWIW The jumper orientation is polar opposite corners, NE to SW or NW to SE depending if your standing on your head or not
Point is, the LP will operate when the correct polar opposite corners are jumped so if it doesnt work at first, try the other opposite corners ONLY. Your weather proof receptacle should be oriented just as the empty LPR receptacle shown above.





And I strongly advise AGAINST jamming s'it willy nilly into any terminal as it may cause "excessive terminal spread" resulting in a faulty/lose electrical connection..
Thats why I suggest taking a minute or two and using the LPR as a model and a normal ave sized metal paperclip, fabricate your own "jumper" like so to protect from protruding to far into the service panels or LPR receptacle and/or possibly damaging the terminal(s).






bookmarking this stuff for future reference.....

Electrical Diagnostic Tools-pdf 14 pages, lots of illustrations and precise descriptions of common "electrical problems".
Explains (quickly) what to look for during a visual inspection, proper techniques for using a jumper wire, advantages and features of and how to properly use digital multimeters, basic electrical stuff that often mystifies, seen as magic by most people.. 'self included..


Connector Experts- Automotive Wiring Harness Repair Solutions

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