Oil pressure sensor wiring on 3800 SC (Page 1/2)
TurboGN APR 23, 10:49 AM
I have a 1988 Fiero GT with the L32 swap. The oil pressure gauge is pegged and I found there are no wires going to the oil pressure sensor. Some info I found says I have to run a wire from the C203 Tan wire down to the center pin of the oil pressure sensor. I looked at the C203 and I don't see a Tan wire. Where do I go from here?
olejoedad APR 23, 11:15 AM
You need to add a wire to the C203 engine side.

Or you could tap into the wire on the chassis side C203 and run it to the OPS, but that wire couldn't be unplugged with the connector if you needed a cradle drop.

The C203 pin designation is 'E' for the OPS signal.

Sounds like your harness builder didn't do a very good job.

Typical swap harnesses also use the OPS circuit as a backup power feed for the fuel pump, utilizing an 88 OPS or similar. This circuit is included in case the Fuel Pump Relay fails.

[This message has been edited by olejoedad (edited 04-23-2022).]

TurboGN APR 23, 11:47 AM

quote
Originally posted by olejoedad:

You need to add a wire to the C203 engine side.

Or you could tap into the wire on the chassis side C203 and run it to the OPS, but that wire couldn't be unplugged with the connector if you needed a cradle drop.

The C203 pin designation is 'E' for the OPS signal.

Sounds like your harness builder didn't do a very good job.

Typical swap harnesses also use the OPS circuit as a backup power feed for the fuel pump, utilizing an 88 OPS or similar. This circuit is included in case the Fuel Pump Relay fails.




Thank you for the information. The previous owner used a 2003 Lasabre wiring harness for some reason. Seems like it makes everything more difficult.
TurboGN APR 25, 08:03 PM
Well it just got worse. Apparently the previous owner must have ripped out the wiring on all the connectors and then just put them in where he felt like it, or trying to match the 2003 Lasabre harness. I went to C203 and where the Tan wire should be for the oil pressure gauge there is no wire at all. I clipped onto the pin below it and that's not the correct wire either.
I then moved on to the same problem with the AC not having any wiring and once again at the C203 both the spots where there should be the AC clutch, and AC request, there is no wire at all.
olejoedad APR 25, 08:50 PM
If you want the harness repaired and to be fully functional, we should talk.
I build and repair harnesses for Fiero swaps and other vehicles as well.

You wouldn't believe some of the crap jobs I've had to make right.

PM me if you are interested.

[This message has been edited by olejoedad (edited 04-25-2022).]

TurboGN APR 25, 09:08 PM

quote
Originally posted by olejoedad:

If you want the harness repaired and to be fully functional, we should talk.
I build and repair harnesses for Fiero swaps and other vehicles as well.

You wouldn't believe some of the crap jobs I've had to make right.

PM me if you are interested.




Thank's, I'll have to go through the whole thing and see if I can get the last few things working or if the whole harness has to be redone.
I just can't quite figure out why they would change all the wire placements, it seems it would make it harder for them to do the swap.

How much do you charge for a full re-work?

[This message has been edited by TurboGN (edited 04-25-2022).]

olejoedad APR 25, 10:43 PM
As I said, you wouldn't believe some of the crap that has come across my work table.

This conversation should move to PM or email.

My email is in my profile.
MulletproofMonk APR 26, 03:38 PM
My memory is that I had to add a pin to the oil pressure connector because the LeSabre has a idiot light, not a gauge.

According to my information:
Oil Sender pin A to C203 pin E
Oil Sender pin B empty
Oil Sender pin C to Engine Block Ground
Oil Sender pin D to PCM C2 pin 19

Edited EDIT:
I believe that I had to either use the oil sender plug off an 88 motor or pull one off a 91-94 Cadillac 4.9L at the junkyard because the LeSabre only had the 2 pin spots.

EDIT:
I have a 1999 LeSabre motor that I just bought Sunday sitting here in the garage... I went and took a picture. Memory is still good.


------------------
-Brian

My 87 GT Poly Suspension Upgrade (all pics) thread
Removing the roof panel
My HUD install thread
Modified stock air canister and base to 3.5 inch for 3800na

[This message has been edited by MulletproofMonk (edited 04-26-2022).]

MulletproofMonk APR 26, 03:47 PM
Also I would recommend Joe if you aren't going to do it yourself. He's been around a long time, hasn't had any issues that I have seen on here and gives plenty of free advice. He and Ryan would be my go-to's.

It is fairly easy to do if you are organized and patient. If you start cutting wires just trying to poke around, you are going to be in worse shape... and better off to pay for it upfront then later...
olejoedad APR 26, 05:12 PM
The backup fuel pump power circuit is not wired per you info, Brian.
Pin A does indeed go to C203 E for the gage.
C and D go to C203 B and L.