While replacing the alternator with an Aspire one, it wont crank when turning key...

[Larry Hampton]

Thanks

[tooldude]

The jumpered fuel test connector can only test the entire fuel pump circuit for the ability to operate the fuel pump at all, a limited test. Lack of the motor running at speed indicates very high or infinite resistance/no connection, a failing motor, or weak battery. Operating the motor without its normal pressure load does not show whether it can develop sufficient power, even though it's spinning. At this point it would be good to clean the ground connection for the inertia switch, (G400), at the center of the hatch looking down into the cargo area), as the entire circuit is depending on that one ground, and could possibly be your problem. If it's not, jumper the fuel test connector (GN/R wire, key on) & check for voltage at the tank (GN/Y). It should be very close to actual battery voltage. No voltage there means the problem is back toward the B+ supply, such as a possible intermittent to the main relay (BK/W), engine fuse, Ign switch, etc. (therefore the clicking?). If B+ is at the tank, check for it at the inertia switch (GN/W). If B+ is at that switch, either you have already found the faulty G400 or the inertia switch does not have continuity.

[tooldude]

Sorry, I remembered wrongly about the ground G400 being an isolated ground - started thinking how that should be tied into the others which it is. It's the AC relay G104 which I believe is isolated.

[Larry Hampton]

I've also swapped pumps out. But thanks for the extra test spots. I have the wiring diagram, but as its just a diagram, it's hard to know where those locations are.

[nitrofarm]

The jumpered fuel test connector can only test the entire fuel pump circuit for the ability to operate the fuel pump at all, a limited test. .

Really ? Are you sure about that Tool? My print shows it removes the VAF micro switch from the equation. Maybe they should call it the "Limited Fuel Pump Test".

[Studebaker]

There are two connectors by the three relays buy the battery. The big connector is c101. Check it for water and or bad pins.

[tooldude]

Really ? Are you sure about that Tool? My print shows it removes the VAF micro switch from the equation. Maybe they should call it the "Limited Fuel Pump Test".

Don't think I'm knocking anything in your post, Nitro, just because it's following yours. You made good points - I respect that. I'm just trying to add a little more help for the guy. OK Larry, yes I'm sure of that. I may not always get the wording perfect because I try to make the posts more concise, but activating the fuel pump by either VAF switch or test connector is a limited test. It does not tell you that there is sufficient B+ at the pump, if there are voltage drops (resistance) in the B+ supply side circuitry, if there are voltage drops in the ground side circuitry, if the motor is beginning to fail or pulling the wrong amperage. The "entire" fuel pump circuit actually has 2 'sides' that are electrically separate from each other - the voltage supply side and the activating side, both going through the main relay. You eliminated, arguably, the most likely problem from the activating side by replacing the VAF at post #51. Lots of power goes through that main relay and relays are one type of component that can suddenly fail. Nitro is right to put you onto it and I would highly suspect it. Want to cut through a lot of crap? Pull out the main relay and make a jumper across the W/BL and Y/BK connectors which will manually power up all the Y/BK circuits. No matter which, if either side of the relay may happen to be bad, the fuel pump should get power. You may want to first check that B+ is actually getting to the W/BL terminal even though you replaced the fuses at post #1. If that pump won't run then, I still believe you should jumper the inertia switch terminals and/or check for voltage at the tank. These things test the circuitry which actually powers the motor. If no voltage at all is making it through the main relay then there will be no voltage at any connector on the Y/BK wire - at the FP relay, injectors, self test connector (an easy check), etc.

[Movin]

The title of this thread should read "Is it possible to diagnose and repair electrical using no diagnostic tools " ?

[Larry Hampton]

Right now every evening this week is taken up with Cub Scouts Twilight Camp.

And I'm not trying to not use any diagnostic tools, I'm trying to get an idea on where to start as time isn't of the essence, but it is in very short supply as far as it being available.

I'll get a chance Saturday, but next week I'll be at Rock Island Arsenal.

[nitrofarm]

^ Just let us know if you need help finding the wires with your test light. Good luck at the Arsenal

[Movin]

The work and activities are really cool, I was having a hard time justifying the substitute a known good part so often as a diagnostic tool. If you have internet access near the car we might be able to save you some time if you had a test light. There are several pages of people so far, someone should be available when you are at your car.

[nitrofarm]

I was just in Oklahoma City,too bad I didn't think of contacting Larry. I'll be going again maybe I can stop by then.

[Larry Hampton]

Even if I don't have problems let me know.