Bad2ndgen

ok im working on a 85 gsl-se and am having some ghost problems. first of all there is no power to the fuel pump, wich is why it wont start. Im not sure where the fuel pump relay is or any fuses that may be related. The other issue is a little stranger! When you step on the brakes or push the trunk relese button the dash lights and one blinker comes on! this seems pretty fu@ked up to me and Im not the best wiring guy. Im not sure if this is a common problem but Any help would be much appreciated. Thanks

85RX7GS

iTrader: (1)

Fuel pump cut relay is located under the dash to the right of the fuse box.

Directfreak

iTrader: (2)

Check your ground connections. Seems recently several of the guys here have problems with a main common ground near the tailights.

FJ

It is on a 12A, but he is talking about a 13B.

On an SE, the relay is called a circuit opening relay and is under the carpet at the passengers feet. But, just to be sure, you do know that you will not hear the pump with the key on "ign"? It only runs in "start" or when the engine is running.
In case you are not aware, the test connector is by the air box. Black with two pins. If you jump it with the key on "ign", the pump should run.
If it does but you suspect, or have checked, that it does not run while turning over, check the trailing spark. With no signal at the trailing coil, the pump will not run.

The voltage for the relay comes from one of the fusible links on the drivers side strut tower. You would lose a lot more than just the pump if it had dirty connections (it also is the source for the ignition switch), but it is worth the time to clean the five of them while you're there. It then goes to the 20 amp "engine" fuse, under the dash.


As Directfreak mentioned, the second problem is likely the rear ground. Both the brake lights and the hatch release solenoid use the same one. (The fuel pump does not use that one, by the way.) Strange things happen when it has a dirty connection. On an '84/'85, you will find it under the plastic surrounding the hatch light.

-John.

Bad2ndgen

thanks for the help, the rear ground worked great but I still haven't got the fuel pump to run. Could you clairfy on the jumper? I tried to jump the one with the white connector and the black housing, is this the right one? If it is, it still didn't make the fuel pump run, I also checked the fuses and all the fusable links look good. Should I try a new relay? or can I jump it? just to try. Also wich is the trailing coil? Thanks.

FJ

Glad the rear ground solved part of the problem.

Well, I tried to respond last night. Shortly after logging in, we started having brownouts then lost power altogether until this evening.

I called the connector black; it is indeed a white connector in a black boot. Beside the green TPS connector. I believe you had the right one.

If you jumped it (with the key on "ign") and the pump didn't run, check for 12V on one of the pins. One should have 12V, the other 0V. If it's not there, either the fusible link or the fuse is bad.

If you do have 12V at the connector:
-Check the ground at the strut tower. (Ground for the fuel pump, and it is the main chassis ground)
-Check the ground on the bar that holds the solenoids. Under the BAC. It's the ground for the air flow meter switch and the test connector (which simply grounds the pump relay as the AFM would) and make sure the engine ground is good. Use jumper cables from the battery neg to the ground on the solenoid bar and try jumping the test connector again.

If that doesn't help;
pull back the passenger side floor carpet and remove the floor pan beneath it. By the wires, you will find the relay. In relation to the attached diagram, the wire codes are:
BW =black with a white stripe
BR =black/red
Br =brown
L =Blue
B =Black
With the key in "ign", check for 12v on the BW and on the Br. Should be 12V on both.
Then jump the fuel pump test connector, always with the key on "ign". You should still have 12V on the BW, but now 0V on the Br.

Check the L wire, and it should be 12V.
-If not, it could be the relay ground (for that coil) at the solenoid mount, or the engine ground, or the relay itself. Ground the Br and see if it's that helps. (It will not hurt, it normally goes to ground when AFM flap opens.)
- if the L wire has 12V, the problem has to be at the pump itself. Check the voltage at the pump.


You can bypass the relay, just to check: jump the BW and the L :
-if the pump doesn't run, it's the pump itself or it's ground. Check at the pump.
-If it does run (and the BW had 12V and you had grounded the Br as mentioned above) then the relay is bad. I would remove it and double check: apply power and ground to test it out of circuit as per the diagram.

Just a general idea of how to approach the problem.
I've attached the diagram for the relay.

The trailing coil is the front one. It has two wires on it's neg terminal connector. The leading only has one.
Good luck.

-John.

Bad2ndgen

John, you are a huge pimp. If for one day I could be as cool as you my life would be fulfilled. Thanks for all your help.

Justin

FJ

HaHa. You're welcome, and thanks for the grin.

-John.