84 F150 2WD auto with 302.

every diagram I find has a four terminal starter relay but my truck has 3 terminal. Truck has a 12/83 build date it.

Dealing with starting issue and want to order new starter relay but the ones for this years have 4 terminals.

I’m pretty sure this is the original starter relay from factory.

I have trigger wire pulled off stud in the picture.



any help clarifying or where to buy the 3 terminal starter relay?

 

Unless you’ve confirmed your original starter relay is bad, I’d keep it. Many of the replacements available don’t hold up very well. Some guys have even gone so far as to scour junkyards for OEM starter relays instead of gambling on an aftermarket replacement. More info here, including how to test a relay and the control circuit to it:

https://www.ford-trucks.com/forums/1...i-mean-it.html

If the relay has failed, you can safely install a unit with two small terminals. The extra terminal was for trucks with an electric fuel pump and was part of the circuit to power the pump while cranking the starter. If not needed, it does no harm just sitting there.

Most aftermarket manufacturers only make the style with two small terminals, as it will work on all vehicles, but not visa versa.

 

1979 trucks and older have 2 small terminals S and I. The "I" terminal provides a full 12 volts to the coil to give a hotter spark while cranking. In 1980 and newer this is done in the ignition switch circuit.

You cannot buy one that is better then what you have. You can drill out the 4 rivets and clean up the internal connections.
​​Flip the large round brass washer over and make it like new. Same with the in and out studs.
Post photos of the overhaul to help those that have the same starter relay.
Jim

 

so if I replace the relay does the trigger got to S or I ?

 

The trigger (red wire?) Goes to the "S". The "I" connection is not used on your truck.

 

"S" is for start. "I" is for ignition which like was said, is not used in the 1980-up trucks except the trucks equipped with the hot fuel handling option with electric pumps in the tank or tanks.

 

‘82 F150 302, when I turn the ignition all I get is a loud click from the ignition starter relay. Replaced with a new 4 terminal relay but get the same result. It had been starting fine. New battery too. Ideas?

 

Welcome to FTE

This post is just what you need to see where the problem is that all you get is a clicking when trying to start.
https://www.ford-trucks.com/forums/1...w-starter.html

You can not look at battery cables and tell if good or bad. Well sometimes if they are really bad you can.
Do you have them bolt on battery cable ends to the cable? If so get new cables as that can be a cause of your issue.
Dave ----

 

Solenoid is working. You can do some testing if you have a meter or testlight. Or just replace all the large battery cables if you want to use the shotgun approach.

P.S. Make sure to keep your old solenoid. Once you get it fixed, you have a 50-50 chance that the new solenoid sticks and you can't turn the starter off. China junk. If you get to that point, put the old solenoid back on.

 

If you do have to replace the starter, this would be a good time to upgrade to an newer type, PMGR starter used on newer trucks.
This also fixes the problem with the low quality stater solenoid problem, as it doesn't have to carry large current flows anymore.
Good luck, Jim

 

Great! Thanks for the help!

 

So if my cables are good or replaced and I still get the click, is it most likely the starter that’s the problem?

 

Before loading the parts catapult (Pull!), run the voltage drop test linked in post #2 above. Ten minutes with a voltmeter and the test results will isolate the fault, whether it's the battery, cables, starter relay, etc.

Make sure your battery is fully charged. This is a very important prerequisite for testing, so please don't skip it.

There's no point insisting the (insert name of part) is good because it is new. Sadly, nowadays many new parts are junk straight out of the box. Run the voltage drop test and be sure. The test was written exactly for your situation and can save you a LOT of money and grief if followed.

 

With out testing like in the link I posted it is a guess where the problem is.
Again you can not look at battery cables and say they are good as they can be bad inside under the insulation.
So test to say yes or no that the cables are good or just replace them..

Note the ground side of battery goes to motor & frame.
There is a ground from motor to firewall to ground the cab.
And a ground cable from hood to firewall on the right side by the hinge.
The solenoid also needs to be grounded where it is bolted to and if the cab is not grounded, motor to firewall, then the solenoid may not have a good ground.

Can the solenoid be bad? Why yest it can and give just a click.
My truck had all new large wire, dont be fooled as some cables look large but itis just the outer insulation you need to go by gauge of the wire cables.
I was using the old solenoid and every now and then I would get a click. I would try and key 3 or 4 times and it would then crank & start.
Thinking a bad connection I cleaned every cable end and even the solenoid to ground.
It was all for nothing as it was worst as the click happened every time I went to start it and I never moved the truck as I was testing it.

When it did start I went right to NAPA and bought the top of the line solenoid and installed as soon as I got home.
Have not had a problem since and it has been 3 years now.
Note I bought top of the line solenoid not a cheap one.

But run the voltage drop test to find where the problem is first.
Dave ----

 

FWIW, I was checking NAPA and see they have a solenoid with three terminals. For my 86' ECH ST402. $55.
I bought the ECH ST404, $38 a few years back, it's been working great.


https://www.napaonline.com/en/search...tor&referer=v2