Help with header install
- Thread starter Chillin014
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ah i see i see.
markcp- did the unit you put behind the intake manifold look like the one in my picture? Im afraid it might be too thick to fit back there but i havent tried yet.
do yall think yall dont evne have the threaded hole like i do down on the bottom of the motor or maybe its plugged from the factory?
markcp- did the unit you put behind the intake manifold look like the one in my picture? Im afraid it might be too thick to fit back there but i havent tried yet.
do yall think yall dont evne have the threaded hole like i do down on the bottom of the motor or maybe its plugged from the factory?
When I did my 355 swap into my V6 85 Cutlass, I installed the factory gauges and proper harness for them. I used the port behind the manifold for both the switch and the sending unit, running a brass tee and a short brass extension tube to get it the right height. It is where the SBC G body harness I used placed it. ( I don't know where the one you used is located) My pressure switch has two terminals in it, not one. The reason for the difference is that the one wire switches provide the ground for the bulb in the dash while the two wire switches provide the positive for the bulb and thus need to have an in and an out. The single position switches ground through the block and require no such provision. To use one with the other all you would need is a simple DIN relay and then wire the switch as either the positive or negative side of the relay's turn on coil with the circuit being provided through the switched end of the relay.
85 Cutlass Brougham said:
hmm, you lost me with the electrical bit at the end there. Ideally, I would like to simplify the set up as much as possible. I dont know what the plug going to the manifold Oil Unit is connected to...but if I could bypass that and use that mounting spot for a single gauge sending unit like i had on the bottom that would be cool. And then just plug the bottom hole of coarse. Sounds like everyone is baffled as to why i have one on the bottom and on the top 🙁
Ok, since you have an 85, you need the two prong switch ( likely) and there should be two units. The bigger gold one in the first pic you posted is the gauge sender. The second one with two prongs is the oil light switch. One is a variable resistance unit that sends the signal to the gauge. The other is the one that lights the light. Like I said, my car has both units. The light plug on mine always comes off and so it never works. The point about the relay is that it allows you to switch from a negative to a positive switch or vice-versa, but it is not necessary for you to understand that- I just threw it in as an aside. Anyhow, the pressure gage wire is tan. The pressure switch wire plug has two female terminals but has 4 wires running into it. I can't see the colors right now because it is too dark out and the wires have black paint on them. All of this assumes you have the proper harnesses in both the dash and engine bay to run the gages cluster. Removing the computer harness would not affect this as it is a seperate harness that runs only the computer and maybe the A/C cutoff at WOT ( only a few engine types had this, most did not). Even the Cruise Control is not dependent on the ECU- it is a standalone system that uses a direct VSS signal and is in no way connected to the computer. I have the 85 wiring diagrams for Oldsmobile models, and the pinouts are usually the same as is the wire color coding...however... the diagram is illogical in how it describes the switch circuit and I can't understand it. The switch looks like it runs a parallel connection with the choke, but it shows nowhere the circuit grounds. Maybe it is supposed to be a series connection instead of parallel? It also fails to take into account the 4 wires running to and from the switch on my harness. So... I dunno...
85 Cutlass Brougham said:
ah i see. well if you have a picture of how you t'd your's off i'd be interested in that since it looks like i'll probably need both. I'd like to replace the big single unit for this piece if possible to save space.
looks like the unit already in there behind the manifold but has the single piece.
I dont know WHY i wrote 85, its actually an 82, if that even matters. I believe everything is connected so it sohuld just be a matter of mounting the unit and plugging that one hole. Any suggestions on plugging the hole?
Hmmm..... now you have me thinking... Maybe the Cutlass with a gauge package did not use the oil pressure light, just the gauge. The manual shows the pressure switch only being used with the non-gauge package cluster, and not on the gauge package harness. I used a 85 Grand Prix 305 harness and it seems to have the wiring for it, but maybe there is no corresponding set of pins in the C100 bulkhead connector for it to work with...
Okay, I can't put up a pic tonight because of where my car is ( up on ramps in a dark driveway in pieces), but will try to do so tomorrow. I looked at mine, and I actually used 3 separate brass fittings to get it all in there. A tee, a male in, female out elbow and either a nipple or a plug. To plug the hole, just go to the hardware store with the piece you took out and tell them you want a plug with these threads and size. They should be able to hook you up. You may also not use the switch because GM may not have used a light for oil pressure in your model. It will still light up in the factory wiring because it is in the choke circuit and the light says OIL/CHOKE on it in most cases. As for the size of the gold sender, you need that to be that big. It is not a simple switch, but a pressure sensitive rheostat that varies resistance based on pressure input. The Ohm range is 0-90 ohms with 0 being 0 psi and 90 being "max pressure" according to my 85 Olds Schematic. To know the exact specifics of your car/truck, I would really need the correct schematic for your particular vehicle's harness as it varies by make, model, engine and options.
That's cool, no problem.
In that case ill keep this ugly bulky thing and stick it back there. I hope it doesn't look too ugly. Should I use that sealant tape for the plug and T fittings?
In that case ill keep this ugly bulky thing and stick it back there. I hope it doesn't look too ugly. Should I use that sealant tape for the plug and T fittings?
Yeah, I think I used Teflon tape when I did mine, but it was 9 or 10 years ago so I don't remember exactly.
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