Author Topic: Oil Pressure Sending Unit Conversion  (Read 4739 times)

Offline A robs 23

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Re: Oil Pressure Sending Unit Conversion
« Reply #30 on: January 11, 2020, 08:04:05 PM »
Haha yeah I switched to a manual choke for my 350 rebuild. I prefer it for canadian winters over the electric.

Are there any suggested methods to secure the PC once I remove that clip, other than duct tape.


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Offline bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #31 on: January 11, 2020, 08:29:50 PM »
The adjacent clip is so close the PCB won't go anywhere.  Besides, the adhesive on tape might chemically react with the plastic and copper foils of the PCB.  I would let it be.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline A robs 23

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Oil Pressure Sending Unit Conversion
« Reply #32 on: January 12, 2020, 05:15:15 PM »
When i ground the oil pressure gauge, the needle returns to low.

**I am going to ensure my oil pressure sending unit wire is the same wire running from plug to pinout. If it is, I will use my multimeter and see if I have an open circuit.

I have a tach signal at the tach. I have 12v ignition at the tach. I also have proper ground. Is it possibly a dead tachometer?

**I am going to re terminate my ground that I created and add solder. I wonder if my ground is the issue.

I removed the second ground from the voltmeter, I no longer have intermittent failure with my voltmeter! Thank you!


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« Last Edit: January 12, 2020, 07:20:35 PM by A robs 23 »

Offline A robs 23

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Re: Oil Pressure Sending Unit Conversion
« Reply #33 on: January 12, 2020, 07:23:40 PM »
I confirmed I have proper ground. I made a new terminal end. Still no tach.

I also discovered that crkt 32(tan) in position 5 of my pinout, is not the same wire that runs to my oil pressure sending unit plug. I checked from the plug to the wire harness terminal, no continuity.


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Offline bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #34 on: January 12, 2020, 11:16:50 PM »
If you have an incandescent test light, clip it to B+ then probe the ground wire that connects to the tach head.  The test light should illuminate normally bright.  If it does, the ground connection is sound.  Once you're satisfied that all the external circuit connections have been verified, you should suspect a faulty tach head. 

In itself, 'no continuity' doesn't necessarily mean you connected the wrong circuit to the oil gauge.  It simply may be open.  You need to perform additional tests for verification.  Use the factory wiring diagram to ID where the oil pressure gauge wire passes through the firewall bulkhead connector.  Check for continuity between the bulkhead connector and the gauge.  Then check for continuity between the bulkhead connector and the sender.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline A robs 23

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Re: Oil Pressure Sending Unit Conversion
« Reply #35 on: January 13, 2020, 11:54:52 AM »
Replacement tachometer on the way.

I will verify bulkhead wiring in the next few days.

Using my multimeter, I connected to the oil pressure sending unit wire and touched the negative terminal to ground. This did not show any continuity either. This is why I am suspecting incorrect wiring.


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Offline bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #36 on: January 13, 2020, 12:06:57 PM »
Using my multimeter, I connected to the oil pressure sending unit wire and touched the negative terminal to ground. This did not show any continuity either.

Still not conclusive since an open in the correct wiring would show zero continuity.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline A robs 23

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Oil Pressure Sending Unit Conversion
« Reply #37 on: January 21, 2020, 05:08:45 PM »
I believe I found the problem. The red circled pin(male/female) is from my crkt31 (tan).

1. What can I do to repin this?
2. Does this look like grease and dirt, or electric burn? (**UPDATE: I have since read a post about a guy who pulled all the pins and cleaned, I will likely attempt this. I am assuming this is the substance that gets more viscous over time)





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« Last Edit: January 21, 2020, 05:38:21 PM by A robs 23 »

Offline JohnnyPopper

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Re: Oil Pressure Sending Unit Conversion
« Reply #38 on: January 21, 2020, 05:47:30 PM »
Flitz Metal Pre-clean followed by small brush and lots of water to rinse the gunk away.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #39 on: January 21, 2020, 06:25:30 PM »
Unless you know for an absolute fact that Flitz is non-caustic, avoid using it on electrical terminals!  I hesitate that Flitz Pre-Clean may be acidic, which could impose long-term damage.

The black "tar" is factory applied antioxidant-sealer.  It's a good thing.  It protects the connections from oxidation.  Don't remove it.  If it's too late and the product has already been cleaned away, replenish it using Truck-Lite NYK-77 (preferred), NOALOX, Ox-Gard or similar antioxidant compound.

It looks like the female terminal was simply dislodged and pushed out of the cabin side of the bulkhead connector.  That or someone relocated/removed it.  Separate the fuse box from the bulkhead connector (2 screws and two clips) and look for the dislodged wire sandwiched between the two.  You may need to slightly bend the locking tang on the back of the terminal then reinsert it into the connector and reassemble everything.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline A robs 23

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Oil Pressure Sending Unit Conversion
« Reply #40 on: January 21, 2020, 06:56:28 PM »
Using my multimeter, and the wiring diagram you provided, I have discovered that there are two crkt31 locations on my bulkhead. I just need to switch, from “old” to “new” as shown on my picture posted.



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« Last Edit: January 21, 2020, 08:12:06 PM by A robs 23 »

Offline A robs 23

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Oil Pressure Sending Unit Conversion
« Reply #41 on: January 21, 2020, 07:16:13 PM »
I swapped the terminal end on my bulkhead to the previously posted location. I now have continuity in crkt 31 from my wiring harness pinout #5 to my oil pressure sending unit plug!

Thank you for the help and guidance!


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« Last Edit: January 21, 2020, 08:14:45 PM by A robs 23 »

Offline bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #42 on: January 21, 2020, 08:14:29 PM »
There are some pieces missing from our conversation.  LOL 

Look at the circuit diagram again.  There is only one bulkhead cavity used for ckt 31.  The cavity you marked as "new" is the cavity for ckt 931, which should be the dark blue wire that originally ran to the choke OPS pictured near the beginning of this thread (second post).  From the factory, ckt 31 is tan from the OP gauge all the way out to the gauge sender.

In real time, what color wire did you connect to the new gauge sender?  Are you trying to repurpose the three-wire choke OPS connector to mate with the new single terminal sender?  The OP gauge sender uses a Packard 56 single wire connector and terminal (images).
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline A robs 23

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Oil Pressure Sending Unit Conversion
« Reply #43 on: January 21, 2020, 08:44:52 PM »
The wire I used to connect to my oil pressure sending unit is tan. Circled below.



When I checked for continuity of my tan wire, pinout 5, it was located in the position of 931 on my bulkhead. Also, a tan wire.

I swapped the terminal end from 931 into 31 location, which was empty, and reconnected the bulkhead.

I then had continuity from pinout 5 to my oil pressure sending unit plug. Previously circled in red. 

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« Last Edit: January 21, 2020, 08:47:02 PM by A robs 23 »

Offline bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #44 on: January 21, 2020, 08:56:26 PM »
Got it.  Someone in the past got creative.  Thanks for the clarification.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)