Is there an Oil Pressure and Water Temp. output signal on 95 LT1 PCM ?

[lionelhutz]

Taking a quick look, it appears to be a oil pressure switch (not sensor, switch) connector. On the early GM fuel injection stuff they put an oil pressure switch across the fuel pump relay. There has been many a thread about this switch being used to control the fuel pump once the engine is running but I have never seen any evidence of that being true. From my experience, it is simply a backup to the fuel pump relay only and I've eliminated it without any issues. I didn't believe it was ever used on a LT1 but it may have been on the early years.

[RobertISaar]

There has been many a thread about this switch being used to control the fuel pump once the engine is running but I have never seen any evidence of that being true. From my experience, it is simply a backup to the fuel pump relay only and I've eliminated it without any issues.

both, really, in every application i've inspected the schematics for. i'm sure there will be exceptions though.

once the engine is running and oil pressure rises above the ~4PSI threshold, the current used to drive the fuel pump is shared between the relay and the oil pressure switch. if one of them fails, the other takes all of the load and the engine continues to run.

[nchittman]

Alright so I will need to install an oil pressure sensor and wiring to connect it to the Blazer's harness. I have not heard back from Techrods yet, had to email could not find a phone #to call at lunch. Time for some internet hunting. Thanks for the replys guys it helped me alot.

[lionelhutz]

I looked through the '96 schematics. I have the GM electronic version '96 to '05 so that's what I looked at. The LT1 was used in the B-body cars, the F-body cars and the Y-body cars. There is no oil pressure switch shown for the B-body and F-body applications but there is an oil pressure switch shown for the Y-body application. I also have other versions of 94-96 F-body schematics and the oil pressure switch is not shown in any of them. Finally, I have been through both an earlier model F-body and B-body harness wire by wire and I can tell you 100% the switch was not in those harnesses.

So, you can decide if you want to use that switch to back-up the fuel pressure relay or not. You can just tie it off in the harness if you want to and it will still work just fine unless the fuel pump relay fails and then you lose fuel.

Knowing this it's easy to see what they did. The harness plug is for a 3-terminal sensor with 2 terminals in use. Looking up a '96 Corvette oil pressure sensor finds this thing.

http://www.ebay.com/itm/ACDelco-1020...item43c2bc0c35

So, the 2 wires they use are the oil pressure switch and the 3rd terminal is the oil gauge sender. If they would provide the 3rd wire in the pigtail you could use one of those sensors I linked for the both functions and keep all the connectors plugged in and looking neat.

[nchittman]

So the LT1 Camaro's, Caprice and Impala's did not have factory oil pressure gauges but my little V6 S10blazer had one. That's Odd.

Lionel thanks alot for the time you spent on this, Hopefully I can help you out some way. Let me know how?? Maybe Structural Welding Info?

I'm going to see if Techrods can supply me with the the correct oil pressure switch / sender connector and the coolant sensor connector with wiring. This will be great to have all my gauges working. Thanks Again

Well I decide to go take a quick look at what oil pressure switch I have and it the 3 terminal. But the connector doesn't have the third wire. I maybe able to go down to our local auto electrical specialist and either have him add the wire to my three terminal connector or sell me the terminal. Thanks Again might get it done this weekend.

[RobertISaar]

So the LT1 Camaro's, Caprice and Impala's did not have factory oil pressure gauges but my little V6 S10blazer had one. That's Odd.

they had them, but they were in no way connected to the PCM as described.

[nchittman]

Just looked at some 95 & 97 Z28 camaro insturment cluster on ebay and both definnetly have Oil Pressure gauges. So the output from the sensor only goes to gauge cluster. The link to the AC Delco Oil Pressure sender/switch also fits 94 thru 97 Camaro's , Firebirds and Vetts.

I agree that they have nothing to do with the PCM.

[lionelhutz]

So the LT1 Camaro's, Caprice and Impala's did not have factory oil pressure gauges but my little V6 S10blazer had one. That's Odd.

I think you confused oil pressure switch and oil pressure sensor in my previous post. The F-body LT1's did not have an oil pressure switch. They did have an oil pressure sensor. It looks like that switch/sensor combo you have but it only has the middle pin where you are missing the wire. There is no switch in it.

FYI, you can also get one that has the outside 2 terminals and is only the switch. You got lucky you used the 3 terminal one that you need to get the gauge working. Good luck finding the terminal and wire.

You could use the 3-terminal unit to replace either of the other 2 units. You can not use one of the other units to replace any of the other ones though.

[AngryCorvair]

Digging up an old thread to ask a semi-related question:

I'm doing a stand-alone LT1 swap from a '94 Corvette into a '65 Corvair, and i'm thinking I'd like to replace my dash gauges with an Android tablet running ALDLdroid. All i really care about is tachometer, water temperature, oil pressure, and CEL.

Question: Has anyone taken the oil pressure sensor output (that normally goes only to the oil pressure gauge) and run it into the PCM, perhaps in the A/C Pressure input, so it can be displayed by TunerPro or ALDLdroid, similar to what has been done with AFR?

Thanks!
PC

[steveo]

just throw that thing through the oil temp input (useless sensor)... it's logged on the standard datastream, i'm sure we can help you get it into your ADX file so it'll display on the dashboard

but honestly if all you want is those four gauges, a tablet seems a bit overkill..hows about a raspberry pi with this thing? it logs too... http://fbodytech.com/misc/raspberry-...arddatalogger/