Vbb199
B-rate Hillbilly Customs
- Joined
- Jan 12, 2018
- Posts
- 9,316
- Reaction score
- 15,949
- Location
- Salisbury NC
- First Name
- Vince
- Truck Year
- 89, 79
- Truck Model
- 89 Suburban R1500, 79 C10
- Engine Size
- 350, 502
so, with revisiting my k5 or "k5ton" im handling electrical in preparation for firing the motor up. i retained the factory 91 wiring harness for the engine compartment, the cab harness was cut to bits and tiny pieces by the PO. so years ago, i purchased a CLEAN and UNCUT harness off ebay from a 87 or 88 4x4, fuel injected suburban. i got everything plugged up that goes to that to the best of my knowledge.
im using holley sniper EFI for fuel delivery on my 502 ci bbc. so with that said, i do not need the ecm, or any of that other stuff. the holley takes care of metering the motor. so far, in my pursuit of having a functional electrical system, i have put in a marine battery, gotten power to the efi, alt, and starter. and ran grounds from the battery to the frame, body, and engine.
i swapped a round eye front clip on the truck, spliced in the wiring,
headlights and tail lights that arent burned out or broken all work. only have drivers turn signals, pass i have nothing, but i will say passenger side bulb is missing, rear turn signal might not even have a bulb.
from the efi's LCD display, i have rpms, as well as actual spark to the ignition.
when i turn the key, motor turns over, efi turns on.
NOW onto the issues i DO have that im trying to diagnose.
on the instrument cluster, when i turn the key for the first time, the temp gauge is just pegged all the way over to HOT, upon turning the key, voltage gives me a reading, oil pressure needle does move. fuel gauge is stuck in place. ( i have sending unit hanging by a hose under the rear of the truck, plugged up, and ground wire ran to the frame.)
i need to know WHY the temp gauge is pegged, and more importantly, why is it when i turn the lights on , it pegs itself even further over towards hot?? i tried what @bucket said, grounding the GREEN coolant sending signal wire to the body or frame to reset it, but to no avail. theres clearly a short somewhere.
to clarify, the temp SENDING UNIT with 1 green wire that goes in the side of the head is hooked up, the CTS sensor that the ECM would normally use (two wires, yellow and black) is not hooked up. the EFI has dominion over that one.
still pegged over. im clueless on that one. i found a few open grounds on the engine bay wiring harness, tied them over to the firewall. still nothing. im at a loss on that one.
NOW.........the fuel pump. i have a ******, old, half working fuel pump plugged in line with the sending unit thats dangling off the frame (nothing conductive suspending it)
i have the fuel pump relay plugged up on the firewall. the wires that lead to it are as follows: green/white, black/white, red, orange, and grey.
the EFI has a 12v wire to power the fuel pump... i wanted to just tie that wire in the relay as a trigger wire (comes on when the key is turned on, also powering the efi)
i thought at first the grey wire was tan, cut it, tied the relay side of the wire to the efi's 12v signal wire, tried cycling the key to turn on the pump, no success. i as well tested at the pumps actual plug with a multimeter, im getting 0.09 volts when the key is cycled on, realized my mistake, fixed that wire with heat shrink, my mistake.
it is not sending signal to the pump. the relay is grounded, and firmly plugged in. i have no reason to think that relay would be bad considering it was pulled from a running truck, but im not taking that option of the table.
next i tried the green/white wire as the 12v trigger wire.... still no success. (that was really just grabbing for straws)
correct me if im wrong. the red is a test wire, orange would be constant 12v , idk what grey would be, black/white is ground, and... green/white im not sure of.
where should i go from here? should i look and see if the relay is actually getting the 12v on the orange wire? is there something additional i may be missing here? each time i tried something different, one thing at a time mind you, i would test the actual connection that the fuel sending unit plugs into on the pos lead of my meter, with a big longass wire ran from battery negative to the multimeters black lead, while that sounds crazy, i did that just to eliminate any chances of poor grounding. im getting 0.09v there, no matter what i do.
im sorry to ramble, im just trying to cut down on obvious questions, and try to give the reader the full story of where i stand...
thanks guys!
im using holley sniper EFI for fuel delivery on my 502 ci bbc. so with that said, i do not need the ecm, or any of that other stuff. the holley takes care of metering the motor. so far, in my pursuit of having a functional electrical system, i have put in a marine battery, gotten power to the efi, alt, and starter. and ran grounds from the battery to the frame, body, and engine.
i swapped a round eye front clip on the truck, spliced in the wiring,
headlights and tail lights that arent burned out or broken all work. only have drivers turn signals, pass i have nothing, but i will say passenger side bulb is missing, rear turn signal might not even have a bulb.
from the efi's LCD display, i have rpms, as well as actual spark to the ignition.
when i turn the key, motor turns over, efi turns on.
NOW onto the issues i DO have that im trying to diagnose.
on the instrument cluster, when i turn the key for the first time, the temp gauge is just pegged all the way over to HOT, upon turning the key, voltage gives me a reading, oil pressure needle does move. fuel gauge is stuck in place. ( i have sending unit hanging by a hose under the rear of the truck, plugged up, and ground wire ran to the frame.)
i need to know WHY the temp gauge is pegged, and more importantly, why is it when i turn the lights on , it pegs itself even further over towards hot?? i tried what @bucket said, grounding the GREEN coolant sending signal wire to the body or frame to reset it, but to no avail. theres clearly a short somewhere.
to clarify, the temp SENDING UNIT with 1 green wire that goes in the side of the head is hooked up, the CTS sensor that the ECM would normally use (two wires, yellow and black) is not hooked up. the EFI has dominion over that one.
still pegged over. im clueless on that one. i found a few open grounds on the engine bay wiring harness, tied them over to the firewall. still nothing. im at a loss on that one.
NOW.........the fuel pump. i have a ******, old, half working fuel pump plugged in line with the sending unit thats dangling off the frame (nothing conductive suspending it)
i have the fuel pump relay plugged up on the firewall. the wires that lead to it are as follows: green/white, black/white, red, orange, and grey.
the EFI has a 12v wire to power the fuel pump... i wanted to just tie that wire in the relay as a trigger wire (comes on when the key is turned on, also powering the efi)
i thought at first the grey wire was tan, cut it, tied the relay side of the wire to the efi's 12v signal wire, tried cycling the key to turn on the pump, no success. i as well tested at the pumps actual plug with a multimeter, im getting 0.09 volts when the key is cycled on, realized my mistake, fixed that wire with heat shrink, my mistake.
it is not sending signal to the pump. the relay is grounded, and firmly plugged in. i have no reason to think that relay would be bad considering it was pulled from a running truck, but im not taking that option of the table.
next i tried the green/white wire as the 12v trigger wire.... still no success. (that was really just grabbing for straws)
correct me if im wrong. the red is a test wire, orange would be constant 12v , idk what grey would be, black/white is ground, and... green/white im not sure of.
where should i go from here? should i look and see if the relay is actually getting the 12v on the orange wire? is there something additional i may be missing here? each time i tried something different, one thing at a time mind you, i would test the actual connection that the fuel sending unit plugs into on the pos lead of my meter, with a big longass wire ran from battery negative to the multimeters black lead, while that sounds crazy, i did that just to eliminate any chances of poor grounding. im getting 0.09v there, no matter what i do.
im sorry to ramble, im just trying to cut down on obvious questions, and try to give the reader the full story of where i stand...
thanks guys!
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