1988 Ford F-250 has a hinky ignition switch. Its gets hard to turn, sticks in the “crank” position sometimes and is generally a pain in the ass. Common problem from what I read.
So, I’ll just rig up a push-button. Put the key in “On” and run a hot wire through a momentary switch to the solenoid. Push the button, and the engine cranks.
Question: Should I run the hot wire to a relay, then to the solenoid, or is this redundant? Isn’t the starter solenoid just a big relay itself?
And not that I give a shit, would that effectively by-pass the neutral safety switch?
Yes, the starter solenoid is a high-current relay, so no, you don’t need another one. Still, don’t use a tiny micro switch for it*!* Back in the day I knew a few family/friends that did this. I don’t know if they still do, but Ford used to have the starter relay separate from the starter, usually attached to the side of the engine compartment under the hood. This makes doing this very easy. GM & Chrysler have the solenoid integrated into the starter itself.
It sort of depends on where you ‘jump’ the circuit but in general, yes, it will defeat the start safeties. If your truck is an automatic the neutral safety will be in the steering column, a sensor that ‘senses’ the position of the column shifter, or possibly inside the transmission itself. If it’s a manual it probably has a clutch pedal sensor, you have to press the clutch down to get the starter to engage. Either way it’s likely that you’ll wind up bypassing them.
Find a real electrical supply shop and explain what you need. This is one application where the big box stuff is contraindicated. Really, really, contraindicated.
The volt/amp is not serious - the real current is done by the solenoid. Your push button will need to have a DC rating (which is NOT the same as an AC rating) and be quite robust - you don’t want it shorting to ‘ON’ when the engine is running.
The ford should have a relay under the hood that you will wire your push button to. Don’t go directly to the starter solenoid, I think the starter relay is near the battery on the fender wall.
no need for an intermediate relay; the current needed by the starter relay coil is at most 1 or 2 amps. I had the same thing on my '84 F-250. When I got it, the push button was there to operate the glow plugs since the old-style Navistar glow plug controller was made out of tissue paper and foil. after updating the glow plug system, I moved the pushbutton to trigger the starter relay instead.
the modern ones are useless to the OP, they’re just an electronic trigger to the PCM. The PCM handles engaging the starter and automatically disengages it when it senses the engine has started.
Rather than re-inventing things, how tough is it to replace the ignition switch? I know some are a cast iron pain as the switch is integrated into the cylinder and steering wheel lock, but on some vehicles, it’s just a matter of pulling off some trim or panels, then two screws and a plug are all that stand in the way of replacing the switch.
A 1988 pickup truck will have the ignition cylinder secured into the steering column. For whatever reasons vans were the last vehicles that still had them in the dash and even those were switched by '88. Replacing a column-mounted ignition switch is a job requiring specialized tools, steering wheel puller etc., and is not something a backyard mechanic wants to attempt. Especially if the owner doesn’t care about having a manual switch.
I had to do this on the kid’s '93 Mercury Tracer. The cylinder still locked/unlocked the steering column fine, but the rotary switch on the back of it broke asunder. I used a starter push button and a 30 amp toggle for the accessory circuit. Kid has a habit of flipping switches with a vengeance, so after the second toggle switch broke, I replaced it with a 50 amp ceramic and brass lab knife switch (Coors brand, no less). She never broke it. The car eventually died, and the lab switch went back to the lab.
I don’t know why, but when the OP said “old truck” I had in mind a 1955 Chevy … with a foot pedal starter on the left … that’s a mechanical connection and a starter button on the dash wouldn’t work …
This truck has problems with the relay sticking as well as the ignition switches getting sticky. The bigger problem is the relay carrying more amps than it was intended to carry. The starter has no solenoid switch so all the current runs through the firewall relay. The most common fix is to upgrade the size of the battery cables. If the battery is slightly running down between charges it will also cause the starter to stick. The system is under designed. I recently replaced the motor in mine and it is slightly tight, not enough to really hear it slower cranking but enough to increase cranking amps. Having serious problems with starter sticking unless battery is fully charged.
