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1987 BBII relay switch to fuel pump

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Old 03-14-2009, 06:12 PM
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1987 BBII relay switch to fuel pump

This relay is laying on fender well, passenger side. It burned to a crisp, both parts. I am pretty sure it has to do with the fuel pump, because when I connect two of the three wires, the engine starts and runs really good and when I disconnect the wires, the engine will turn but will not start. Do not know what the third wire goes to. I do want to replace the relay, but do not know what to ask for and I do not have the old one to take with me to the parts store. Any help, please?
 
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Old 03-14-2009, 09:48 PM
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It sounds like you are referring to the "fuel pump relay", though it might also be the EEC relay (though they are technically the same relay except maybe for color).
 
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Old 03-15-2009, 11:25 AM
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One wire will be to going to the device, one wire will go to a ground, and the other wire will be going to an "Enable" signal line that turns the relay on or off.

As a general rule of course. The fuel pump relay is designed to be on at all times the engine is running, or while starting. It uses also a prime function via the computer to power on the fuel pump(s) for about 4 seconds when the key is just turned to 'on' but not start.

Reason I bring this up? You've got 3 leads. One will be "hot", one will be "Ground" and the other line will be for the switch 'on/off' You can use a test light, and a few turns of the ignition key to 'on' to locate the signal line. Any parts house should carry replacement relays, and from the sounds of it? You'll probably want to pick up a socket. (wiring diag. will prove helpful as to how to wire in the replacement).

S-
 
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Old 03-15-2009, 02:35 PM
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Thanks so much for the great info, Big help.
 
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Old 03-15-2009, 08:21 PM
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Tedy Bear, Will one of these wires be hot with ignition on or off? Hot all the time?
 
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Old 03-15-2009, 10:04 PM
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As noted, a wiring diagram will be very useful (even the one in Chiltons/Haynes is adequate). One lead is hot at all times, and a second lead should be hot KOEO/KOER.
 
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Old 03-15-2009, 10:35 PM
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Thanks, I believe I hve it clear now...
 
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Old 03-16-2009, 12:09 PM
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Originally Posted by mrshorty
It sounds like you are referring to the "fuel pump relay", though it might also be the EEC relay (though they are technically the same relay except maybe for color).

Hope this is last question about the relay. I have ordered a socket and relay thru Napa. According to them, it is a 3 prong socket and relay. (I do have 3 wires)
I do know mine was green. Do you think we are on the right road?
Thanks
 
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Old 03-16-2009, 02:55 PM
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Heres what the factory diagrams show for the relays:

EEC relay solid yellow wire is hot key on or off

Red/light green stripe & black/light green stripe are hot with key on

Solid red is hot with key on.

Pump relay solid yellow wire is hot key on or off.

Solid red, tan/light green, orange/light blue are hot with key on.

FYI the PCM grounds the voltage on tan/light green to close the relay & turn on the fuel pumps.
 
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Old 03-16-2009, 05:43 PM
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Originally Posted by MessengerII
Hope this is last question about the relay. I have ordered a socket and relay thru Napa. According to them, it is a 3 prong socket and relay. (I do have 3 wires)
I do know mine was green. Do you think we are on the right road?
Thanks
Don't think so. as 87XLT points out, the wiring diagram shows 4 lead to the fuel pump relay: one lead from the battery, one lead from the EEC relay, one lead going to the pump, and one lead going to the PCM/self-test connector. You might want to have NAPA check what they are getting.

FWIW, the fuel pump relay and the EEC relay are essentially the same relay (except maybe for case color). If your EEC relay and socket are still intact, you should be able to use those to compare.
 
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