99 Rav4 no power to fuel pump

[mastersat1]

I pulled the pump out and checked voltage at the pump connector and had no voltage. What powers the fuel pump. Does Toyota run through the oil pressure sending unit like GM? Which relay is for fuel pump, none of them are labeled "fuel pump". HHHHEEEELLLLLPPPPP is greatly appreciated.

[ctwright]

If you don't see one that is labeled fuel pump, meaning that they are all labeled for something else, it is probably mounted up in your dash and you will have to lie on your back looking up under behind the steering wheel to find it, since you already have the fuel pump out you know which color wires to look for, I don't think that it is wired like GM with the oil pressure switch. Also to though, you said that you pulled the pump out and checked for voltage at the connector, did you also take the connector loose from the pump and then no voltage at the connector. I tried to trouble shoot one before one time, and checked for voltage at the connector that goes down to the pump, it didn't show anything, I checked both wires right after having the key turned on, nothing. Well, I then went through all of the trouble finding the relay in the dash, checked the wires there, and didn't have power on the wire there at the relay but had power on the coil side of the relay, so I thought the relay contacts were bad. Took the relay out and tested it and it was good, so then I got the idea of going back to the connector at the pump and unplugged it, and then hooked the relay back up, and then it showed voltage at the connector that goes to the fuel pump when the key was turned on. Just thought I'd add that you may have checked it unplugged not sure though. The problem was a bad fuel pump.

[mastersat1]

The plug to the pump only has 2 wires. I checked voltage there unplugged from the pump. If relay is under dash, will it be labeled. You normally will hear it click when turning key on. I don't hear any under dash.

[ctwright]

Originally Posted by mastersat1

The plug to the pump only has 2 wires. I checked voltage there unplugged from the pump. If relay is under dash, will it be labeled. You normally will hear it click when turning key on. I don't hear any under dash.

I already know your plug has two wires who said it didn't. One of those two wires is going to your relay I may have accidentally wrote which wires instead of wire when I said you can tell which color wire is going to your relay(which will have 3 other wires also going to it) if so my bad. This might sound like a dumb question but you did already check your fuse first right, if that is blown you will not get power to either your control circuit side(coil) or power circuit side(contacts) of the relay?



Relay coil = @@@

Relay Contacts = -\ -

12V+ in Run or Start --~~~(fuse)-------------- @@@ ------- ECM ground pulse (control circuit)

12V+ in Run or Start---~~~(same fuse)---------- -\ --------- Fuel Pump ------Ground (power circuit)

Hope that helps that is how it should be.

[mastersat1]

I got it guys. I finally found the fuel pump relay under passenger side kickpanel. I pulled it and swapped it with the main and all ok. Is it possible it was just stuck in the open position and when power was removed it straightened itself out. I dunno. Thanks

[ctwright]

Originally Posted by mastersat1

Is it possible it was just stuck in the open position and when power was removed it straightened itself out. I dunno. Thanks

No, because you were already removing power to the relay every time your switch was turned off, well, unless they don't have it wired like I showed above but it should be wired like that. Also you mentioned that you switched it with another relay, you didn't say you switched back.

[mastersat1]

One terminal was battery voltage and the other one was keyed voltage. No, I didn't swap them back. But I figured that since it was the "main relay" that I swapped it with, then if it was bad I wouldn't have had keyed voltage for it to even turn over after the swap. One other thing that I discovered was that the pump didn't get voltage until you turn the key to start. I mean the pump wasn't powered until the engine was cranking.

[ctwright]

Originally Posted by mastersat1

I mean the pump wasn't powered until the engine was cranking.

Well, if you look at the diagram I showed you it showed that the coil in the relay does not get power until it gets the ground pulse from the ecm. The other side has of the coil has battery voltage with the key in the on position. The ECM should however send the ground to the relay coil with the key in the on position also for about the first 3 seconds. Meaning you should be able to hear the pump run when you first turn the key on, not cranking.