2 oilswitches?

[fatbob]

Well I pulled the TBI 350 out of the 88 crewcab last night and found two oil switches on it. The oil pressure guage did not work when I got the truck, so I bought a new switch and installed it in the back of the intake. An aftermarket gauge was hooked up there, and the plug from the wiring harnesswas there so it seemed like a no brainer. But the factory gauge still didnt work. Now I find this other switch right over the oil filter, and I wonder if the wiring harness is somewhat universal with plugs in both places.

 

[diesel4me]

mm..

I think the one at the oil filter is for the computer if I recall correctly..I might be wrong though..do both sending units have the same number of prongs??..some trucks used one for the choke,some had it combined in one sender with the oil sender..its been awhile since I had to look one up--I know they had a lot of questions in the listings( how many prongs,0-60psi gauge,0-80psi gauge,etc)..very confusing..it usually took 2 trips at least to send a customer the right one...

 

[pauly383]

The one behind intake works gauge .

The other one , in my books diagram , is the fuel pump oil pressure relay switch . I believe its bypassed for cranking , and upon starting , it just waits to cut of the engine when you drop oil pressure suddenly .

My 83 actually had one , I think for the ESC distributor , its useless now , I have regular HEI form a 76 Nova .

 

[dyeager535]

TBI motors of that vintage should have a single prong oil pressure sender that goes to the gauge (brown wire) and an oil pressure switch for the fuel pump that is two wires.

IF you have to rewire and/or replace connectors, I suggest a later switch/sender combo (I believe a '90 or '91 K5 will have one, later cars will, I have part numbers if needed) as all three wires go to the same piece, and are a much more compact package.

 

[fatbob]

Thanks guys,
Th truck ran with out the top one hooked up so that one must be for the guage only. It has two prongs. I think the three pronged ones did the guage and fuel pump relay. The one by the oil filter only has 1 wire I think.
Pauly, I might be hitting you up for those diagrams if I can't remember where all the bs hooks up too.
Can you see the hole in the front of the block?
I gotta go get me some JBweld

 

[pauly383]

If you need them I will e-mail them to you