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 Posted: 09-08-2006 04:03 am
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Paul Koehler
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I've been driving around all summer with nary an issue with my JH. I knew it was to good to be true!. Today, I started up and went to the drug store - after completing my mission (not Viagra!), and attempting to go home, it would not turn over. It just played dead. I could hear the fuel pump running (NAPA Facet Knockoff) but that was it. I wiggled the wires on the selenoid and made sure battery had tight connections and still  nothing. Finally I borrowed a screwdriver from a passerby motorist, and jumped the two terminals on the selenoid while enlisting the aid of a kid gawking at my COOL CAR, to turn the key. It started immediately, and I made it home.

I know the PO replaced the ignition switch. Are they subject to failure? Anybody got any ideas?

Thanks-PK

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 Posted: 09-09-2006 12:44 am
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Mark Rosenbaum
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Due to the federally mandated Infamous Seat Belt Warning Module (ISBWM), a JH may fail to crank for any number of reasons.  The ignition switch, when activated, applies power to the ISBWM.  If, and only if, (a) the parking brake is activated, and (b) the seat belt for each occupied seat has been buckled, will the ISBWM allow the start relay to be energized.  This relay, in turn, applies power to the starter solenoid.  The starter solenoid applies power to the starter motor, which cranks the engine.  A failure anywhere in the chain will prevent the engine from cranking unless manual intervention of the sort you describe, takes place. 

The (inexpensive, available) relay is present so that the electrical load on the (expensive, rare) starter switch is reduced to a sensible level.  Consequently, it is rare for a JH ignition switch to fail if the car's electrical system is stock or nearly so.  The relay and ISBWM may fail more often.

Often, an owner will defeat the ISBWM, or avoid the need for replacing a defective one, by jumpering pins 11 and 12 on the round wiring connector that plugs into it.  This permits the ignition switch to energize the start relay directly.  This also allows the Fasten Belts and Key In Ignition And Driver's Door Open warning functions to operate normally (assuming they still work, of course).  More extensive alterations, such removing the entire ISBWM system and associated switches and wiring entirely, would disable the two warning functions.

The relay, ISBWM, and turn and hazard flashers, are all located on the driver's side kickpanel forward of the dash.

Last edited on 09-09-2006 12:45 am by Mark Rosenbaum

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 Posted: 09-11-2006 01:57 am
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Paul Koehler
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Thanks Mark. I connected both seat bets and applied hand-brake, and it cranked over. However, when I looked through the box of old parts, that came with the car, I noticed, what I am guessing to be a component that is so flat, it can only fit under the seat.

In comparing pictures on Jim K's web site to what I have on the left kick panel, it is all still there. So, I'm kinda at a loss, unless the flat part in the spares box is just a buzzer apperatus; there is no buzzer present when the key is turned-PK

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 Posted: 09-11-2006 01:54 pm
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edward_davis
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The under-seat switch is a grey disc.  At least, it was in my JH when I pulled it out earlier this summer.  It was duct-taped into the rubber straps under the seat, with two wires coming off.  Can't remember the colors.

Of course, my JH doesn't have any of the original interlock 'brain' left, so I just cut the wires short that go to the seatbelt buckles.  That whole system is a nightmare, which is why cars today aren't required to work that way.  Couldn't have the ol' remote start if someone had to be sitting in the driver's seat with the belt buckled....  It also makes it a pain to check on a running engine if someone has to remain in the driver's seat the whole time...

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 Posted: 02-10-2007 01:31 pm
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Bill Rister
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Apparently a previous owner has disconnected at least part  of that seat belt/parking brake/ignition set-up because my car will start with the parking brake off and no seat belt connected.   But I still have intermitant starting on the first turn of the key.  I've wondered if perhaps the key isn't seating correctly or if contacts just aren't contacting each time in this 34 year old system.    And that has made me do a bit of thinking...
I recall in the late 1930's my aunt having a Ford coupe with a dash-mounted push-button starter switch.   It worked with the ignition on or off ..I know 'cause as a left-alone-in-the-car-kid I pushed that button and the car lurched forward.   Scared the pants off me!
I've thought of doing this and wonder if anyone has already done so ...why not a push-button discreetly placed in an out of the way, not easily seen, place under the dash or elsewhere, connected between the battery and hot terminal of the solenoid?
With the ignition switch on, a push of the button should cause the solenoid to do its job on the first push. 

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 Posted: 02-10-2007 03:34 pm
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Mark Rosenbaum
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Bill, what you suggest is quite easy to do using almost any automotive-rated switch (such as a pushbutton or momentary-contact toggle switch).  The details vary slightly depending on the specific version of JH.

Cars with start relays:
Mounted high on the kick panel, under the dash on the driver's side, are the turn and hazard flashers and the start relay, which activates the starter solenoid when the ignition switch is turned to the START position.  Attached to the relay's socket are a black wire, a brown wire, and two white-red wires -- one to the ignition switch, the other to the starter solenoid.  The added pushbutton is connected between the brown wire and the white-red wire that runs to the solenoid (NOT the one that connects to the ignition switch).  You may remove the relay, if desired, to disable engine cranking when the ignition switch is turned fully clockwise.

Cars without start relays:
In these cars the white-red wire runs between the ignition switch and the starter solenoid.  Here one connects the added pushbutton between the brown and white-red wires on the wiring harness side of the ignition switch connector.  To disable engine cranking via the ignition key, the white-red wire (NOT the brown wire) attached to the ignition switch must be disconnected.  This is best done by extracting the white-red wire from the ignition switch side of the ignition switch wiring connector, and taping up its connector pin.

Attachment: red button.jpg (Downloaded 107 times)

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 Posted: 02-10-2007 04:11 pm
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Bill Rister
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Thanks Mark ... What I had in mind was simply clipping wire(s) running from the dash area to the .250 connectors on the solenoid, and taping off the disconnected wires.  Then attaching the switch between a wire running from the battery to the hot side of the solenoid.   Since there are two .250 connectors and one of the mounting posts is grounded I'd assume the negative side would automatically be grounded when the solenoid is mounted thus allowing me to simply run a ground wire from the 2nd .250 to a body ground.

It's an idea I toy with when I do not have the rare luck of starting at first key twist. 

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 Posted: 02-10-2007 05:39 pm
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Mark Rosenbaum
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Bill, I hadn't thought of going that route -- too simple and obvious an approach, perhaps.

The +12 volts to operate the solenoid could come from the spare blade connector of the battery junction on the positive battery cable.  Then, disconnect the factory white-red wire at the starter solenoid, and connect the solenoid's terminal to your added switch.  The other end of the solenoid's coil is grounded through its case, not a terminal on the end, so you won't need to add a ground wire.  The big copper strap carries +12 volts to the starter motor when the solenoid is energized.  The terminal with the white-slate wire provides +12 volts to the ballast resistor when the solenoid is energized, thus bypassing the ballast during cranking.

This arrangement avoids cutting any factory wiring, and allows an easy return to the original setup if you, or some future owner, should ever wish to do so.

Attachment: solenoid terminals.jpg (Downloaded 100 times)

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