Fuel Pump Issues on the relay

Hey all,

First post here, and I need you guys help before I ended calling a mechanic. I'll do it in cliff notes to make it easier to read.

1.Drove home on the HWY and car just died.

2.Found out that my v belts broke and messed up all the wiring. Yes the wiring is messed up from the previous owner try to hardwire the LED lights etc etc

3.Try to crank it and won't start, start one time with starting fuel (fuel pump issues).

4.Did not hear the fuel pump prime when trying to start the key to acc.

5.Check the relay and there is no power on the relay.
http://easyautodiagnostics.com/ford/4.9L-5.0L-5.8L/fuel-pump-relay-tests-3

6.CheCk the ECM and relay and there is low voltage coming from the ignition to the pcm.
http://easyautodiagnostics.com/ford/4.9L-5.0L-5.8L/fuel-pump-relay-tests-3

7.Check the fusible links, There are a bunch and one of them do not have 12 v. Fixed it and have 12 v, try to put everything together and when i connect the battery terminal, the engine turns by itself which means i might have jump it while fixing the fusible link.

8.When the engine turn, there it still won't start, so that's mean there is still no power to the relay.

Car is 1986 ford Bronco II cologne engine. How do i fixed the issues? How do I find out which fusible link is connected to the starter and prevent it from jumping it and turn the car while connecting the battery. Ill take pics of the mess once I get home.

Help please.

The engine turning over when you connect battery +ve means to me that you the battery +ve and the wire from the starter on the same post of the fender solenoid. The fender solenoid should have all the wires EXCEPT the starter wire on one big terminal. The starter wire goes to the other big terminal. There is a small terminal that the ignition start wire goes to, Bat +ve when key on only.

Yes, look at the starter motor
See the big wire(cable) on it
Follow that wire up to the inner fender, unhook it from where it is now, large post on Starter Relay(solenoid)
Connect it to "other" larger post on that relay with NO OTHER WIRES ATTACHED TO IT, if other wires are there remove them

Put ALL the other wires on the "other" larger post, they are the Battery + cable, Alternator wires, Fuse box wires, basically all the 12volt wires including the Fusible Links

The Larger posts do not have an assigned "side", as long as starter motor cable is on its own, all will be as it should be.

There will be 1 or 2 smaller posts on this relay, you want the one marked with an "S"
Red/blue stripe wire connects to the "S" post, this comes from the Key switch, when this wire has 12volts starter motor will turn, so it should ONLY have 12volts when key is turned all the way to START

If you have a second small post on the Relay it will be labelled "I", if used it would have a wire that runs to Coil "+" terminal, not sure they still used this in 1986

In the engine bay there will be an OBD1(VIP) self-test connector hanging off main wiring harness
Could be passenger side firewall, drivers side firewall or near battery
In 1986 it is probably right near fuel pump relay
Drawing of it here, second one down: http://www.therangerstation.com/tech_library/OBD_I.shtml

Fuel pump slot is IDed, if you use a jumper wire in that slot to a GROUND, then Fuel Pump Relay will close when ever key is ON(RUN)
So turn key ON, then GROUND that slot, you should hear FP relay click closed, and fuel pump should come on

OBD1 connector location here: http://ww2.justanswer.com/uploads/fordguy4u/2011-12-20_222417_a1.jpg
Self-test connector

ok. I finally figured it out. Retest and still no power on the relay connector that is powered by the ignition switch. The ignition switch itself is working since i can crank the engine via the switch. I concluded that thats the issue. refer to the pic where theres no power from where i pointed.

The fuel pump prime when i connect a wire from the #3 wire connector straight to the battery. I couldnt find the diagnostic switch for the love of God. i think the previous owner removed it.

So how do i trace the wire and get power from the ignition switch?

thanks.

It is a short wire, it doesn't get power from the ignition switch itself

The ignition switch closes the PCM(EEC) relay, Brown base, which then sends power to PCM(computer), fuel injectors, spark system, and fuel pump relay, this is the "key on" power for that relay, usually a Red wire

So there should be a Red wire on one terminal in the Brown base PCM relay, that is the Power OUT of that relay and is spliced to power the PCM, injectors, spark and fuel pump relay(not fuel pump, just the relay)

The diagnostic switch will be buried on the passenger side close to or under the blower motor / fan housing on the firewall.

RonD said:

It is a short wire, it doesn't get power from the ignition switch itself

The ignition switch closes the PCM(EEC) relay, Brown base, which then sends power to PCM(computer), fuel injectors, spark system, and fuel pump relay, this is the "key on" power for that relay, usually a Red wire

So there should be a Red wire on one terminal in the Brown base PCM relay, that is the Power OUT of that relay and is spliced to power the PCM, injectors, spark and fuel pump relay(not fuel pump, just the relay)

Click to expand...

So how do i proceed from here. There's power on the eec relay. The only thing that has no power is the one i pointed on.

I see what you pointed to but have no idea of what that slot on the FP base should be

On the back is that slot a Red wire?

On my wiring diagram I have 4 wires for FP relay:
1. Black/yellow stripe wire is 12volts IN from FP Fuse or fusible link, always has 12volts key on/off doesn't matter
2. Dark Green/yellow stripe wire is 12v OUT to fuel pump/inertia switch

3. Red wire 12v IN from EEC Relay, Key on 12volts
4. Light Blue/orange stripe wire Ground from Computer(EEC), only a Ground for 2 seconds with key on, or when engine is running, this wire is also connected to the VIP OBD1 FP Slot so you can Ground FP Relay full time for testing

So if wiring matches and you have no 12volts on the Red wire with key on, then you will need to find the break in the wire or cut and splice a new wire in from EEC relay to FP relays red wire

RonD said:

I see what you pointed to but have no idea of what that slot on the FP base should be

On the back is that slot a Red wire?

On my wiring diagram I have 4 wires for FP relay:
1. Black/yellow stripe wire is 12volts IN from FP Fuse or fusible link, always has 12volts key on/off doesn't matter
2. Dark Green/yellow stripe wire is 12v OUT to fuel pump/inertia switch

3. Red wire 12v IN from EEC Relay, Key on 12volts
4. Light Blue/orange stripe wire Ground from Computer(EEC), only a Ground for 2 seconds with key on, or when engine is running, this wire is also connected to the VIP OBD1 FP Slot so you can Ground FP Relay full time for testing

So if wiring matches and you have no 12volts on the Red wire with key on, then you will need to find the break in the wire or cut and splice a new wire in from EEC relay to FP relays red wire

Click to expand...

The slot is for the yellow wire. And i believe it's powered by the eec relay. Initially the eec relay connector has no power on one of the slots. I fixed it by replacing the fusible link. Should i check the EEC relay to make sure it's good? I tried swapping the fuel pump relay and EEC relay and still doesn't work. Could both relay be broke?

There is power on the red wire (low circuit) but no power on the black/yelow stripe wire. If i hard wired the Green wire straight to the battery, the pump will prime.

The black/yellow stripe wire should go to a fuse or fusible link and be connected to the battery, usually via the starter relay post with the other fusible links, or engine fuse box if its a regular fuse

When the relay closes the Black and Green wires are connected, and the battery voltage is sent to fuel pump, thats why when you jump battery voltage to the Green wire the pump comes on, so Black wire needs to have voltage all the time
You can use an inline 30amp fuse or replace the fusible link

To activate/close the FP relay the relay's coil needs 12v and a Ground, those are the other 2 wires
Red wire gets 12volts from EEC relay, key on
Light blue OR Tan/green stripe wire is the Ground wire computer uses to control fuel pump power

If red wire has voltage with key on then FP relay should "Click Closed" for 2 seconds each time key is turned on

RonD said:

The black/yellow stripe wire should go to a fuse or fusible link and be connected to the battery, usually via the starter relay post with the other fusible links, or engine fuse box if its a regular fuse

When the relay closes the Black and Green wires are connected, and the battery voltage is sent to fuel pump, thats why when you jump battery voltage to the Green wire the pump comes on, so Black wire needs to have voltage all the time
You can use an inline 30amp fuse or replace the fusible link

To activate/close the FP relay the relay's coil needs 12v and a Ground, those are the other 2 wires
Red wire gets 12volts from EEC relay, key on
Light blue OR Tan/green stripe wire is the Ground wire computer uses to control fuel pump power

If red wire has voltage with key on then FP relay should "Click Closed" for 2 seconds each time key is turned on

Click to expand...

Ill check the black wires for voltage. But for now how Do i fix the yellow wire so it will have voltage?the wire went all the way to the main harness so I don't know where to start the repair. Didn't see any broken wire before it went deep to the harness. and i check all the fusible link on the distributor and all of them has power. There are 2 slots on the distributor. One slot it just for the starter wire right and the rest goes to the other slots correct?

update:

Thanks for your help. I did the Relay test from the link. Here's what I found weird. When I use the multimeter and probe the connector, it will not show any volt with black lead on the battery and red lead on the connector. It did show power on both red/yellow wire with key on ignition with red lead on the battery and black lead on the connector. Does it mean I put it on back wards on the starter relay? After putting the relay on the connector and ignition on, I did not hear the fuel pump prime even though it is showing power on both red and yellow wire on the connector.

I have check the fusible links and turned out the large yellow wire was blown, replaced it and now it's back on. I also replaced the black wire fusible link (20G) which I think is the one that supplies the fuel pump relay connector. If not which one?

I have a new issues. I tried to start it but only hear click at the solenoid and the starter will not turn the engine.I went and get it tested and they said it was bad. I removed the starter which has two wires. Red (small) and red(2/4g) wires from the stock starter. The new starter that I got, has only one place to mount the wire which I ended up mounting the bigger wire. Refer to pic.

I tried to start it again, and the problem still persists. Just a clicking noise from the solenoid. I tried to jump start it with one cable to the + battery and one end to the small post (ignition wire) and still just making clicking noise as well as the big cable that connects the starter jumped. I tried to use a screw driver to jump start one terminal (big) to another big terminal and nothing.

I have checked the battery cable that is mounted to the solenoid + and show 12 v. I check the - battery cable and ground to chases and both show 12 v. I checked the wire that connect the starter to the solenoid and it has 12 v. Where do the small wire goes in the new starter?

I am at lost here. One problem after another and need your help. It sounds like easy electrical but has no other way of fixing it.

thanks.