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-   -   fuel pump relay ground problem (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/fuel-pump-relay-ground-problem-1009181/)

ben.farnath 08-22-12 03:40 AM

fuel pump relay ground problem
 
fuel pump had no power to it so I checked the relay under the steering column with a test light. When I touched the ground wire the pump switched on. Do I need to trace that wire and find why its not grounding or can I splice in and ground it somewhere new?

Unrelated second question, where can I take ignition start signal closer to the starter motor. My car used to be auto so doesn't have the wire that clips onto the starter that manuals have to allow the starter to turn on.I must have inadvertently removed a wire the previous owner had rigged up.

satch 08-22-12 04:04 AM

There are two grounds for that relay. The solid Black wire (lower left position) is a constant ground and is for starting the car. The Brown wire (lower right position) is another ground wire that has a ground 'only' when the engine is running above 500 rpm.

ben.farnath 08-22-12 04:07 AM

Ok It was the brown wire that I touched that had the pump turn on. What the crap do I do/test new. And might I point out the shear extent of your electrical knowledge is astounding.

satch 08-22-12 04:16 AM

The Brown wire should only have a ground w/the engine running and key to on and not just w/the key to on but engine not running w/the caveat being you're testing the fuel system and the fuel check connector needs being jumpered, which is the same thing as physically grounding the Brown wire.

So with key to on and the engine off the pump should not turn on in a normal sense.

ben.farnath 08-22-12 04:26 AM

Oh ok good and it should turn on with the key held to start but probably only when I resolve my starter issue as well?

satch 08-22-12 04:31 AM

The starter wire is in a Blue plug near the trailing coil. It feeds a B/W wire that runs to the starter solenoid. Before the B/W wire reaches the solenoid it forks in two where one part runs to the starter solenoid while the other part runs to pin 3B of the ECU, which is known as the Start Signal. At the ECU this wire runs back to the Circuit Opening Relay and provides power for the upper left positioned wire so this wire would have voltage w/key to start. When it does the Blue wire in the relay should have power as well.

ben.farnath 08-22-12 04:38 AM

Awesome thanks once again. Ill be checking these tomorrow. Its 930 at night here. Close to firing up the engine for the first time. Need to order some vacuum caps to finish off emissions removal. Buy a couple of silicon joiners. An adaptor for bov. And join the bac to the I/c pipe unless there's somewhere else I can rejoin it to.

ben.farnath 08-23-12 02:05 AM


Originally Posted by satch (Post 11196561)
The starter wire is in a Blue plug near the trailing coil. It feeds a B/W wire that runs to the starter solenoid. Before the B/W wire reaches the solenoid it forks in two where one part runs to the starter solenoid while the other part runs to pin 3B of the ECU, which is known as the Start Signal. At the ECU this wire runs back to the Circuit Opening Relay and provides power for the upper left positioned wire so this wire would have voltage w/key to start. When it does the Blue wire in the relay should have power as well.

There is no blue plug.the only one in the entire engine bay is part of the emissions rats nest stuff. But either way I ran a wire from the starter and even if I touch it directly on the start solder joint on the ignition switch and turn key to start...nothing. But if you touch it to acc or one of the others it cranks (probably not advisable I know) must be something faulty in the ignition switch. Have to buy another one? Or is there an easier solution? Ie a starter switch that runs to the starter and to the ign1 and or ign 2 on the switch so with key to on and the new remote starter switch pressed that runs the starter. Or will this not run the fuel pump or fire the coils.

satch 08-23-12 02:26 AM

The Black/Red wire found in its own plug at the Front harness of the ignition switch is the starter wire. There are three wires from the ignition pigtail which has voltage w/key to start. One powers the switch but has constant voltage, the second one powers the IG1 fuses and the third is for the starter.

ben.farnath 08-23-12 02:45 AM

The only plug at the ignition area that is single is black and green at the loom end and that is where I connected the starter plug. I had to deal with a hacked up ignition switch loom thought I had it right maybe not.

ben.farnath 08-23-12 02:52 AM

I get power out of the ignition switch at all points except start so something is definitely wrong.

satch 08-23-12 02:58 AM


Originally Posted by ben.farnath (Post 11197604)
The only plug at the ignition area that is single is black and green at the loom end and that is where I connected the starter plug. I had to deal with a hacked up ignition switch loom thought I had it right maybe not.


Since your car was an automatic then I believe the B/G wire of the Front harness would go to the starter as I forgot your car was initially an auto. At the pigtail of the ignition switch the White /Red should be what powers the switch, B/W powers IG2 fuses, B/Y powers IG1 fuses, Blue powers ACC and the remaining thick wire should be Black/Red which goes to the starter.

ben.farnath 08-23-12 03:02 AM

Oh duh. Yup I'm gonna have to make sure the wiring to do with the automatic has been rewired right and is still connected. off to search for a write up on conversion.


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