Need help identifing items on engine

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Houston Ben

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HI, could someone tell me what these are? They are located on the back side of the 327 that I just swapped out for 5.3 and I am trying to figure the wiring out as the person I had swap the engines didn't label them....so pissed right now!!

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I thought one of the above was for the engine temp but then I saw this on the drivers side of the engine.

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Now I think that is for the temp??

Please help this lost soul!!
 

J Knight

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On the first pic the one the right is oil pressure sending unit and bottom pic is coolant temp sending unit.
 

Swims350

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x2 for retro both are oil pressure sending units/switches and the other is temp switch/sender.
 

foamypirate

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I'd guess the oil sender on the right is for the gauge? And the one on the left is probably a switch for the choke heater circuit.
 

Jims86

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I'd guess the oil sender on the right is for the gauge? And the one on the left is probably a switch for the choke heater circuit.

Choke circuit on carbs, fuel pump interrupt on EFI.
 

Houston Ben

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WOW, thanks guys! So this brings up more questions. I had the harness wiring place stub out for these things in the original harness. When looking at the plug for the oil pressure on the right in the first pic it has three wires going into it

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The light green wire on the top doesn't lead to anywhere, I think it was plugged into the pressure valve on the right in the firs pic, the other two go to the gauge cluster, an I correct on the light green wire?

thanks again!
 

Houston Ben

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One more thing, is there any way to check these wires at the cluster? Can I hook each individual wire to some power and watch the needle on the cluster jump to tell what it is to???

Thanks
 

chengny

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That plug is deceiving. The dark blue and the light blue are spliced together within the plastic casing of the plug.

For sure that 3 wire plug goes to the oil pressure "switch" (the one with 2 prongs). It closes when engine oil pressure reaches about 10 psi and supplies power to the choke heater to start opening the choke.

The other - bell shaped - one is a "sender". It provides a variable resistance to ground depending on the oil pressure (0-60 psi). That variable resistance is used to position the oil presure gauge on the dash. It connects to the cluster via a tan wire.

Both of these units have distinct terminations. The switch for choke heater operation is supplied from the factory with a wrap-around locking cover.

The tan wire to the sender - single terminal - has a nice tight boot at it's termination that is designed to snap into the groove on the top of the bell.
 

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89Suburban

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That plug is deceiving. The dark blue and the light blue are spliced together within the plastic casing of the plug.

For sure that 3 wire plug goes to the oil pressure "switch" (the one with 2 prongs). It closes when engine oil pressure reaches about 10 psi and supplies power to the choke heater to start opening the choke.

The other - bell shaped - one is a "sender". It provides a variable resistance to ground depending on the oil pressure (0-60 psi). That variable resistance is used to position the oil presure gauge on the dash. It connects to the cluster via a tan wire.

Both of these units have distinct terminations. The switch for choke heater operation is supplied from the factory with a wrap-around locking cover.

The tan wire to the sender - single terminal - has a nice tight boot at it's termination that is designed to snap into the groove on the top of the bell.

I'd like to meet you in person some day and shake your hand sir.


Posted From Hell
 

Houston Ben

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Dang!!! Thanks for the info! You all are awesome!
 

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