can someone please tell me what exactly these relays do? ive marked them all with question marks. a few people have told me that the one of the right is the fuel pump relay.... does anyone here know what exactly this thing does? im converting my TPI to carb, so i dont know if i really need it any more. could you guys give me a detailed description of what each relay does? also, that thing on the far left, what does that do? is it wiper related? im trying to eliminate as many underhood wires as possible.

 

I know the box on the far left is your headlight module--you need that! Makes your lights go up and down.
Fuel pump relay is needed for your fp to cycle on--don't think you'll need that if you're going to carb.

 

relays dont prevent things from burning out do they? they just "relay" signals to other places right? what happens if i directly wire up my fuel pump to the acc and igniton power sources at the same time? will it fry? can i use that relay to make a branch between the ignition power source and the acc source?

 

From left to right. As tony said... the 1st is headlight module. Electronic Spark Control module, Fuel Pump relay and, if your car if MAF, one is the MAF power relay and the other would be the burn-off relay. If it's speed density, I'd guess they were the fan relays. If you're yanking the wiring anyways, you could always trace the wiring to the source as well.

 

the source always seems to be under the dash towards the ecm......

 

Heh.. sorry.. I sould have been more clear about that.
Most all relays under the hood have a heavier gauge wire running to them and a diff color coming out of equal gauge going to what the relay powers.
Eg.. the fan relay has a heavy orange wire running in from the battery (as most all the relays do) and usually a heavy black/red wire running to the fan. A light gauge green/white wire runs to (or from) the ECM which switches the relay and a tan/white runs to the bulkhead for switch +12v to power the relay (not power the fan itself).

 

hm.... you seem to know alot about electronics. heres what ive done to my fuel pump and VATS relay.... ive cut the black fuel pump wire right where it comes from under the car, into the car. then i drilled a screw into the body right next to it and attached the ground to it. then i cut the tan wire and ran it up to where the VATS relay is. i pulled the relay off, and stuck a thick thread of wire in-between all the little posts where the relay plugged into. so basicaly all the wires that plugged into the relay are now touching. i havent tryed to crank it over yet like this because i want to know what will happen first if all these wires touch. i want to connect the fuel pump tan wire to this cluster of wires and then to acc power. does this sound like a good idea? or am i creating a bomb here?

 

this is a pic of the relay that i am talking about before i started the butchering. dont forget to read my above post

 

Oh now.. I wouldn't go getting your hopes up there... :sillylol:

I don't know how the VATS relay is wired since I've never dealt with those but, if it's wired anything like a standard relay is, you could end up with a slight problem (like an electrical fire, worst case scenerio...).

If you're wantng to power your fuel pump, which, since you've converted to carb, I'm not sure why you'd want to use a TPI fuel pump on a carb but, that's not what you're asking about, the relay needs a source of (switched preferrably) power from the fuse panel and a ground (or vise-versa). Next you'd need a power source in, most likely from the battery and your FP on the outgoing side of the relay.
If you have all the terminals of the relay together, then they are all touching the ground which can be a bad thing if the power wires are not fused. VATS relay is probably wired different but, then again, I don't know w/o a diagram.

Here's a fan relay diagram to sort of help explain the nonsense I'm talking about....

 

i wish i knew what a fuseable link was.... i seriously know nothing about electical stuff or how to properly read diagrams. i probly should have taken an electronics class in high school. im still haveing trouble understanding what exactly relays do. something uses a small electrical current to close the relay, so that it can connect another electrical current.... why not just wire up the fuel pump directly to the ignition power source? technicaly the pump should be running at all times on acc anyway, exept when the engine isnt running

 

If you're curious about relays, a easy to understand explination can be found here... http://www.howstuffworks.com/relay.htm

I'm not a carb guy and really don't know much of squat beyond adjusting the idle on them but, the TPI FP is able to push fuel pressure up to 50psi which I know isn't good for a carb. If you were to want to use an electric FP, I'd think using a TBI FP and a regulator would be a better route. Don't take that as gospel though since I'm not into that stuff about carbs.

Having the fuel pump on a toggle switch controlled relay (that is powered when the ignition is on only) would be the way to go IMO... but that is only my opinion, I could be wrong.

 

Yeah you should definitely listen to deadbird, i really can't explain how relays work, don't have the time but with that thread of wire in each terminal would would definitely cause some problems for yourself. It would be like taking two live wires and touching them together which would cause a short, blowing a fuse or burning up a fusible link, or start a fire. And if it were me i don't think i would bypass any of the relays. if you run direct power to the fuel pump from the starter for example i think you would be bypassing the fuse too. I mean you may be able to see what i am talking about by looking at that fan diagram that deadbird supplied,and the relay is also somewhat like a fuse, sometimes they burn up, like a fuse, so it saves you the hassle of running another wire, and i know you don't want to do that. not sure exactly but I would make sure from someone else, who really knows what they are talking about. hope this helps some. Good luck