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car sat for 8 months. Fuel pump & starter don't work when ignition  Rating:  Rating
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 Posted: 05-07-2006 12:57 am
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GeorgeXYZ
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When I turn on ignition switch, instrument panel works (fuel indicator, volt meter, fasten seat belt light [and two others beside it]).  However, fuel pump is dead silent. When I twist ignition to engage starter, nothing happens.  Starter turns over when I run power directly to it.  Haven't tried to directly power fuel pump.

Are the two problems related?  Where should I start troubleshooting?

Fuel pump is SU 1307 (installed in 1995, according to PO's records).

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 Posted: 05-07-2006 02:44 am
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Mark Rosenbaum
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The fuel pump derives its power from the ignition switch through a rather convoluted path.  If your brake lights work when the ignition is on and you step on the brake pedal, you can assume that this wiring remains in good shape.  Barring PO intervention, there are no fuses involved, so if you have power at the white wire in the trunk, the pump can be expected to operate.  If not, give the pump a few gentle whacks with a mallet and see if that helps.  If there's no power at the white wire, it's probably broken or the pickoff at Fuse #2 may be bad.

In some cases a PO may have incorrectly used the wiring for the factory hardtop's rear window heater to power the fuel pump.  This wiring normally has an inline fuse in the trunk, and if the fuse should blow, the pump obviously would quit.

For early cars, the START position of the ignition switch activates a relay that in turn activates the starter solenoid, thus powering up the starter motor.  Here, the ignition switch, relay, solenoid, or associated wiring may be bad.

For later cars (basically, those made for North America 1974-up) the START position of the ignition switch runs to the Infamous Seat Belt Warning Module (ISBWM), which determines whether or not to activate the relay that operates the starter solenoid.  The ISBWM is also connected to the under-seat paddle switches and seat belts, and the hand brake.  Unless the seat belt for each occupied seat is fastened, and the parking brake is engaged, the ISBWM prevents activation of the relay that in turn activates the starter solenoid.  A failure anywhere in the system will prevent anyone from starting the car -- something to be reflected upon every time one drives through a railroad crossing.

Try fastening the driver's seat belt when sitting in the driver's seat; that may allow the engine to be cranked.  Or, you can disable the system by jumpering pins 11 and 12 on the round connector that plugs into the ISBWM.  One of these pins normally has a white-red wire, the other a lightgreen-red wire, but this may differ for your car.  There should be tiny numbers on the plug itself.

If problems persist, you'll have to do some troubleshooting.  If you desire originality, spare ISBWMs appear cheaply on eBay from time to time, or you can discard the entire system, losing two functions: (a) the seatbelt warning light and (b) the buzzer that sounds when the key is in the ignition and the driver's door is opened.  With a bit of rewiring and a buzzer available from Delta Motorsports, you can regain function (b).

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 Posted: 05-08-2006 01:15 am
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upstate mike
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Check your fuses. I don't know about the starter but the fuel pump did the same thing to me after sitting fo a couple of months through the winter. I was getting my test light out to start checking and as soon as moved the fuse it scrapped through the corrosion and everything was good. Cleaned them all up and no problems since. By the way Mark thank you for answering my steering question. You reafirmed what I thought,

 

                        Mike K.

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 Posted: 06-07-2008 11:44 pm
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Lash Russell
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Hi Mark,

     I'm having the exact same problem as George.  When I turn the ignition key the familiar click-click-click of the fuel pump is not there and further turning the ignition key the starter does not engage.  You mention jumping the ISBWM points #11 and #12 together.  Where is the ISBM and when doing this should I disconnect the wires coming from #11 and #12?

     Thanks in advance.

Lash

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 Posted: 08-10-2008 08:17 pm
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dwalls1
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Spent a frustrating hour last night getting power past the fuse box to the pump. Green wires behind the fuse were not well connected. Once those were stripped and soldered all was well again. Don't quite understand why the pump wouldn't work as the white wires don't seem to be fused, but whatever it takes. This also restored function to the park brake light and gave me a chance to clean up some PO mystery wiring in the trunk. It did not restore function to the tach which is why I was screwing around there to begin with and lead to the release of the smoke in the mystery wiring.

     Why are old wires that are freshly stripped and appear shiny and clean so difficult to solder even with flux core?

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 Posted: 08-10-2008 09:49 pm
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subwoofer
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Soldering wires is not the easiest task no matter what, and old wiring does always have an oxide layer even if it appears shiny, that's at least my experience.

--

Joachim

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 Posted: 08-10-2008 10:06 pm
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dwalls1
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Thanks for reassuring me that I'm not losing it. I shouldn't have assumed that the appearrance was an accurate indicator. I have some fancy liquid flux that I should have used. I hope I don't have regrets down the road, as I didn't get the flow into the joint that I would have liked even though the function is good for now.

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 Posted: 08-11-2008 06:27 am
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subwoofer
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Fancy flux = acid flux?

Stay away from the plumber's flux, that meant for piping - not electronics and electrical work. May cause corrosion down the road.

Crimp style connectors would be a better solution that soldering for must automotive work, I think. Get a good tool (not cheap) and some quality connectors (still cheap), this avoids exposing the cable to unnecessary heat, avoids solder creeping up under the sleeve, etc.

Never, EVER, solder a cable end before crimping or mounting it in a screw terminal. That will cause a loose connection down the line.

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 Posted: 08-11-2008 02:30 pm
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jcdean
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I work in aviation and we have gone away from crimp splices as a rule.  we still do crimp pins in plugs, but use this:

http://www.calcentron.com/Pages/fusion_solder_heat_shrink/fusion_solder_heat_shrink.html

for inline splicing now.  All you need is a heat gun and life is good.  The red ring in the middle is solder and flux mixture and each end shrinks and has an enviromental shield that keeps out the moisture.  Good stuff.

Joey

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 Posted: 08-11-2008 04:10 pm
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subwoofer
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That really looks like good stuff!

--

Joachim

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 Posted: 01-14-2009 09:55 pm
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mdutch
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dwalls1 wrote:
Why areĀ old wires that are freshly stripped and appear shiny and clean so difficult to solder even with flux core?

Well I've not been around much lately, but wanted to get an answer back, as I've worked in audio and wiring for years. NEVER use "flux core" solder. You want "Radio" solder that's ROSIN CORE. Acid core solder used in metalwork and plumbing will corrode the fitting.

Second, when using old wiring, get a spray can of flux-remover or a small brush with lacquer thinner (and a rag to catch the drips) to clean the wires -- the wires probably have an oily residue from being around gasoline and oil.

Third, use a proper soldering gun and just enough heat to melt the solder. A pencil-type, not one of those giant guns. You can get a pencil-type soldering iron for under $30 at an electronics store

Fourth, you don't HAVE to use a crimp connection, in-line, though I am in favor of using them for terminations. Make sure you have a good mechanical connection. (Use a Western Union Splice) for inline splices, then wrap with shrinkwrap or tape)

Last edited on 01-14-2009 10:02 pm by mdutch

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 Posted: 01-15-2009 04:33 am
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dwalls1
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Thanks for posting Dutch,  I did mean to say rosin core solder, I was told many years ago that acid core would not last as the acid continues to eat the good stuff. I haven't had any electrical problems since that one bout last August. I sent the tach off to Mo-Mar and it has worked well since, not cheap though. Had a great trip to Carlsbad last September and we're looking forward to Tucson next month. Good to hear from you, and God Bless.

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 Posted: 01-20-2009 04:08 pm
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smcmanus
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I have had problems with junk solder sold at local retail chains.  This stuff DOES NOT work.  It is crap.  Stick with a name brand American made solder, like Oatey or Sterling.

Those solder connectors were my idea, I just never followed through on it!  It is brilliant!

Good Luck

Steve

 

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