As mentioned earlier, my car has been carbed and with a turbo 400 for a while now, but I'm totally removing all unnessasary wiring and related computer components, what I'd like to do now is simplify how my in tank pump operates, I'd like it to be one of two ways, either by Toggle switch for anti theft purposes, or just switched on during start up with the key and I'll just employ a different type of anti theft deterrent later, now just let me know which under dash wires to utilize to get this going, please include wire color, locations, and schematics if available, and the vehicle in question is a 1992 RS, formally a 305 TBI car, already have the Mallory regulator, plus car and in tank pump worked fine prior to the removal of computer and associated wiring, but haven't heard my pump operate since! I'm stumped, and it's a good time to do it correctly once and for all, Thanks in Advance....

 

I have done a search Guys, but found different years and applications gave several results, just want specific instructions for my needs, thanks......

 

Give this a read

https://www.thirdgen.org/forums/elec...mobiliser.html

 

The pump runs from a relay controlled by the now gone ECM as well as a oil pressure switch that runs the pump once the oil pressure over 4psi.
Depending what you did to the engine bay wiring the OP switch should still be in place and functional so the pump should run as soon as you crank the engine over

 

With a carb swap , some like to retain the relay and wire it to run Ign on ;
all you actually need is the OP switch because the engine will fire up on the fuel in the carb bowls and the pump will kick in straight away.The pump will turn off as soon as the OP drops when you kill the engine.

If you use the relay you can put the kill switch that new power wire from the Ign switch that you have to install; with the OP switch you disable the tan / white power feed to the pump

 

if you intend to put a switch in the tan/white wire it has to be able to handle constant current of pump, 20 to 30 amps. i like the relay better because they carry the current better than switches, as far as longevity of the component. the switch will work but the relay will work longer.

 

Oil pressure switch is gone now, and a standard oil pressure gauge fitting is being used in its place, so that's not an option at this point.

 

Ok, with that being said, how do I start from scratch with a New Relay, what wires have to be employed, I see the Tan/White does something, and I know it should be grounded with a black wire at the back below the rear seat, but what wires for my year do I need to locate to bring into action to make the operate the second I turn on the ignition, and take it slow, not good at the wiring/electronic side of things!lol.

 

the diagram i have for 92 tbi says gray to pump, dk green/white to pcm. so this is how i would wire it if you are going to put a switch in. gauge fuse apparently is where the pump is powered from and that is on the key only. this relay configuration retains the power from that and will shut off with the key or switch. wont turn on with just the switch though, the key will have to be on. if you cant get at the old relay connections or your wires are different let me know. my car was different because it was an 87

 

This looks like exactly what the doctor ordered, I will look this over the weekend when I get the time to play with the RS! Thanks again.

 

Just an update:

I have come to the conclusion that my I tank pump is fried, as stated earlier I had this thing wired to the switch with a separate relay, and it worked great, but since the computer/wiring removal, I thought I did something wrong, but after straight wiring it from the battery and even putting my Mangafuel 300 pump on the wire coming from the relay and grounding it, and then hitting the key to see if the relay was bad, but I was pleasantly surprised when it came right on, so I'll be adding my fuel cell and pump earlier than expected, because replacing the intank pump is not an option, I fact the tank itself will be coming out all together! All electrical components are operational, except for drivers side low beam headlight, thanks for all the help Guys, I hate when a topic is not finalized with a solution to the problem or answers!

 

me too

 

I have wired mine to a switch inside the vehicle. I found that a grey wire on the driver side of the vehicle under the hood on the firewall wires going inside the cab there seems to be a grey wire and if i touch that to 12v it turns on the pump. I eliminated my relays and all.

 

I had that wire in play, and it used to work fine with a relay prior to the computer/wiring removal, but it appears that the pump is dead, came to that conclusion when jumping it straight wired from the battery gave no results, it will be switched when I add my external pump and fuel cell with the relay tho!

 

I see. I had a 383 lt1 in my car before and i removed the entire engine wiring last week cuz i went to a 355 old school carbed.

 

wiring just a switch is not good procedure. the switch is not really designed to handle higher current loads, thats why you should wire the switch to control the relay like he is. the switch will work for a while but will fail much sooner than with the switch controlling a relay.

 

Exactly! Relays are very important and proper Grounding, Im not a electrical or Wiring Guru, but I know that, do it right once and never look back!