Author Topic: Oil Pressure Sending Unit Conversion  (Read 12864 times)

Offline bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #15 on: January 04, 2020, 02:41:28 PM »
The factory w/gauges IP connector has one additional pnk/blk (ckt 39) and one additional blk (ckt 150) wires than the w/o gauges IP connector.  If your question concerns the addition of these two circuits then you have the option of cutting an existing pnk/blk and resplicing two-into-one (image); similarly with the black ground.  Alternatives are to run completely new 18-gauge wires from the IP connector directly to a fuse box ignition tap and the cabin sheet metal ground OR install 6" long jumpers between one of the existing IP connector pnk/blk (39) wires and one of the existing blk (150) wires to the new pin locations using all new IP connector terminals.
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 #16 on: January 07, 2020, 06:37:02 AM »
Thanks!

I have rearranged my wires. Am I correct in identifying that I am now going to no longer use circuit 25 and 50 (brown)?

Additionally, the wiring diagram shows a line running from circuit 30 (pink) to circuit 30(pink) on the w/ gauge pinout.

Do I need to splice and add another pink terminal to my pinout, or does this mean something other than splicing?




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« Last Edit: January 07, 2020, 06:39:16 AM by A robs 23 »

Offline bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #17 on: January 07, 2020, 09:44:23 AM »
Circuit 50 (I+ only in the "run" position of the ignition switch) should be reconnected to circuit 25 (I+ exciter circuit for the internal regulator in the alternator) through a 1N4002 - 1N4007 silicon diode, completely bypassing the cluster.  The diode's cathode will point toward ckt 25 (image).  Without this modification, the alternator will not recharge the battery.  Adding the diode replaces one of the necessary functions of the red no-charge indicator light eliminated from the idiot light cluster.  CAUTION - connecting ckts 25 & 50 directly together w/o the diode will melt the 18-gauge wiring and lead to an electrical fire!

Circuit 30 is the signal lead from the fuel tank sender to the dash gauge.  I believe that two ckt 30 connections to the cluster are redundant to compensate for multiple PCB configurations.  Inspect the cluster PCB to determine which foil path runs to the fuel gauge and pin the single ckt 30 wire accordingly. 


Edit:  added image
« Last Edit: January 07, 2020, 11:57:41 AM by bd »
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 #18 on: January 09, 2020, 02:10:11 AM »
I am learning a ton!

I have tried to figure out which diode to use, based on the range of diodes you provided.

Is this information found somewhere? Or is this something I can figure out with my multimeter?

How can I educate myself on learning which diode to use?


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Offline bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #19 on: January 09, 2020, 10:50:59 AM »
Google 1N400x diode.  The 1N400x series listed are 1-amp diodes.  The only difference between them is their inverse voltage tolerance with 1N4002 being 100 volts and 1N4007 being 1,000 volts.  Use any in the series.  If you have to buy a pack, purchase 1N4007.
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 bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #20 on: January 09, 2020, 11:36:49 PM »
In lieu of a diode, you can substitute a ~20 Ω, 3-watt resistor.
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 #21 on: January 09, 2020, 11:47:41 PM »
I was able to purchase a small package of the diodes for under $2.

I just installed my new coolant temp sender for my gauges. I chose to use the intake manifold location as I would have has to unbolt my headers and power steering pump to remove the old 1/3 switch.

I plan on tackling the electrical in the next few days. I purchased all the required tools to solder that you mentioned.

I grabbed too small heat shrink tubing though. A closer look at your picture with the diode, I realized the structural integrity of the two wires locating inside the heat shrink was pretty critical.

I will post pics of progress soon.


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Offline A robs 23

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Oil Pressure Sending Unit Conversion
« Reply #22 on: January 10, 2020, 04:37:31 PM »
I have almost finished my install.

When I initially plugged in my new cluster with gauges, my oil pressure gauge climbed to max and now it wont come down. I unplugged the plug from the oil pressure sending unit, still no change.

My tachometer is also not working. It sits at 500RPM at all times. With and without ignition.

I verified I am plugged into the distributor.
I verified I have 12V ignition.
I verified I have a proper ground.

At one point I played with the ground while at idle and it seemed to jump to 1200RPM but did not change with actual RPM.
« Last Edit: January 10, 2020, 08:38:00 PM by A robs 23 »

Offline bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #23 on: January 10, 2020, 08:50:24 PM »
Assuming the new PCB configuration you have matches the factory "with gauges" cluster for 1986, repin according to the alternate (with gauges) IP harness connector illustrated on the schematic.  Otherwise, you will have to map out the new PCB and repin accordingly.

Why did you remove the images of the PCBs and the repinned IP connector?  Repost them.

Did you map out the new PCB and compare it to the circuits on the wiring diagram or just repin the connector?
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 #24 on: January 10, 2020, 08:55:52 PM »
Old PC


Tach conversion PC





I felt my post was disorganized. I wanted to make my post a bit more organized to read.

I removed and labeled all wires and repinned based on the schematic you guys provided.



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« Last Edit: January 10, 2020, 09:10:28 PM by A robs 23 »

Offline bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #25 on: January 10, 2020, 09:56:12 PM »
When I initially plugged in my new cluster with gauges, my oil pressure gauge climbed to max and now it wont come down. I unplugged the plug from the oil pressure sending unit, still no change.

My tachometer is also not working. It sits at 500RPM at all times. With and without ignition.

I verified I am plugged into the distributor.
I verified I have 12V ignition.
I verified I have a proper ground.

At one point I played with the ground while at idle and it seemed to jump to 1200RPM but did not change with actual RPM.

Ground the oil pressure gauge sender wire.  Does the gauge drop to zero?

To which distributor terminal is the tach signal wire connected?  Probe the signal wire at the back of the tach head using an incandescent test light.  Does the test light brighten with increasing engine RPM?


I removed and labeled all wires and repinned based on the schematic you guys provided.

After mapping out the new PCB against the IP cluster connector using your posted images, it seems to be correctly pinned.  However, the voltmeter should have only two of its pins connected: one to ground, one to I+.  It appears to have two pins grounded.

Did you figure out why the left turn indicator was always illuminated?

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 #26 on: January 10, 2020, 10:47:06 PM »



I will attempt your suggestions tomorrow!


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Offline A robs 23

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Oil Pressure Sending Unit Conversion
« Reply #27 on: January 11, 2020, 12:00:05 AM »
Tach wire for gauge is connected to tach side of distributor.

Checked distributor with multimeter, it reads voltage and increases with rpm increase.

Grounded oil pressure gauge cable. The gauge remains pinned full.

Would you mind clarifying your point on the voltmeter having two grounds? Did I pin incorrectly?

I believe the harness was not fully plugged in. I no longer have the left turn signal issue.

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« Last Edit: January 11, 2020, 12:14:23 AM by A robs 23 »

Offline bd

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Re: Oil Pressure Sending Unit Conversion
« Reply #28 on: January 11, 2020, 01:01:14 AM »
Tach wire for gauge is connected to tach side of distributor.

Checked distributor with multimeter, it reads voltage and increases with rpm increase.

Grounded oil pressure gauge cable. The gauge remains pinned full.

Would you mind clarifying your point on the voltmeter having two grounds? Did I pin incorrectly?

Recheck the tach signal at the tach head.

An oil pressure gauge pinned past maximum implies an open in the sender wire.  Use a short jumper and momentarily ground the signal wire pin on the back of the oil gauge.  With the ignition ON does the gauge drop to zero?

The IP connector is pinned correctly, but you've installed one too many clips to the back of the voltmeter.  Remove the clip circled in red in the attached image.
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 JohnnyPopper

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Re: Oil Pressure Sending Unit Conversion
« Reply #29 on: January 11, 2020, 01:03:24 PM »
Is that a manual choke handle? I haven't seen one since my old '57 Apache! Thanks for the memory...
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