Author Topic: Mystery Wire?  (Read 5745 times)

Offline 76_Scottsdale

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Mystery Wire?
« on: November 06, 2007, 10:30:30 pm »
Well I had to start a new post cause the other one was screwed up. Well a long story short I noticed this wire on the back of my block coming out of the stock wiring harness. My harness is not hacked at all so it is definitely a stock wire. It is blueish in color and has a rubber single female spade connector on the end. The pics are blurry but they are shot looking down the back of the block, with the distributor in the bottom right hand corner. Thanks for looking.




1976 Scottsdale K20
350 C.I.D.
700R4
NP205
2 1/2" Lift
305/70/R16 BFG MT
True Dual 3" Flowmaster 40 Series Exhaust

Offline 85MudMonster

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Re: Mystery Wire?
« Reply #1 on: November 07, 2007, 01:28:17 am »
It could be a wire for an option that your truck doesn't have. Can you trace it and see where the other end goes?
Dan

85 Chevy K10 - 408 BBC from a 71 Chevelle SS, TH350, NP208, 33" Mastercraft Courser M/T

Offline 76_Scottsdale

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Re: Mystery Wire?
« Reply #2 on: November 07, 2007, 01:44:44 am »
It goes into the firewall fuse block. There really aren't options on my pickup. It's a Scottsdale with nothing fancy on it, no A/C, no PW or PL none of that jazz. It's weird I never noticed it before and I can't really see anywhere to hook it up.
« Last Edit: November 07, 2007, 01:46:33 am by 76_Scottsdale »
1976 Scottsdale K20
350 C.I.D.
700R4
NP205
2 1/2" Lift
305/70/R16 BFG MT
True Dual 3" Flowmaster 40 Series Exhaust

Offline VileZambonie

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Re: Mystery Wire?
« Reply #3 on: November 07, 2007, 07:10:38 am »
Give more vehicle info. Was this a factory gas engine? What does the truck have in it? Is it AC equipped?
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline 76_Scottsdale

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Re: Mystery Wire?
« Reply #4 on: November 07, 2007, 01:00:03 pm »
1976 K20 Scottsdale, factory 350, SM465, NP205, No A/C, no power windows or locks.

It has a rebuilt 350 and I just swapped out the SM465 for a 700R4 everything else is stock and rebuilt on this pickup.
« Last Edit: November 07, 2007, 01:02:17 pm by 76_Scottsdale »
1976 Scottsdale K20
350 C.I.D.
700R4
NP205
2 1/2" Lift
305/70/R16 BFG MT
True Dual 3" Flowmaster 40 Series Exhaust

Offline VileZambonie

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Re: Mystery Wire?
« Reply #5 on: November 07, 2007, 01:25:07 pm »
It could be a wire for an option that your truck doesn't have. Can you trace it and see where the other end goes?

Do you mean it goes into the bulkhead connector? If you can take a pic of which pin it is on the bulkhead connector we can ID it on a wiring diagram. Try to focus your camera a little better for it.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline VileZambonie

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Re: Mystery Wire?
« Reply #6 on: November 07, 2007, 01:29:38 pm »
According to my schematic the dark blue oil pressure sender wire goes to the bulkhead connector. 3rd wire over from Lto R and second row down looking at the connector in the engine compartment.

What's connected to your oil pressure sender near the distributor? Do you have gauges or idiot lights? turn the key on and ground the wire and observe the oil pressure gauge/light
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              ⌠ŻŻŻŻŻ'   [☼===☼]
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline 85MudMonster

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Re: Mystery Wire?
« Reply #7 on: November 07, 2007, 03:25:04 pm »
Vile you counld be on to something there...
Dan

85 Chevy K10 - 408 BBC from a 71 Chevelle SS, TH350, NP208, 33" Mastercraft Courser M/T

Offline Captkaos

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Re: Mystery Wire?
« Reply #8 on: November 07, 2007, 04:14:21 pm »
It looks to be the oil pressure sender, but he indicated in the other post that it had a oil gauge, and in 76 it was mechanical...

Offline VileZambonie

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Re: Mystery Wire?
« Reply #9 on: November 07, 2007, 05:45:12 pm »
It looks to be the oil pressure sender, but he indicated in the other post that it had a oil gauge, and in 76 it was mechanical...

Are you positive it was mechanical in 76? My 74 was but my 75 wasn't
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                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline zieg85

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Re: Mystery Wire?
« Reply #10 on: November 07, 2007, 08:17:50 pm »
That plug pictured IS oil sending unit which IS blue.  At least mine are.  My $.02  If I had to guess the truck originally came with the idiot lights and someone upgraded the gauge cluster.
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline wrangler

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Re: Mystery Wire?
« Reply #11 on: November 07, 2007, 08:29:58 pm »
I swapped my lights for guages this summer and I had the same wire wrapped up against the firewall.  I'm almost positive that it's for the oil guage, since I'm using it now.

Offline Captkaos

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Re: Mystery Wire?
« Reply #12 on: November 07, 2007, 10:35:09 pm »
Are you positive it was mechanical in 76? My 74 was but my 75 wasn't
I am certain that it was on the full gauge setup.  Generally speaking the oil gauges on 73-77's were mechanical.