Starter relay replacement
 

Replaced the starter relay on my son's '84 Ranger (2wd, 2.8 V6, manual trans) with one I picked up at Autozone. Thought I was careful to put all of the wires back in the positions they were before but was a bit thrown off by the new relay having 4 posts vs. the original three. Truck started fine several times with no issues. I go to work, my son starts his truck, and now the starter solenoid will not disengage when the truck starts (necessitating the removal of the positive battery terminal from the battery to break the circuit).

I'm feeling like a bit of a dumbass right now. Looked in my Chilton's manual for the truck and it shows only the most basic of diagrams to the circuit. I have two fused links (one orange 16 ga., and one red 18 ga.) on the same post as the positive lead, a black wire (about 18 ga) and the black lead to the starter on the other post (the post closest to the cab), and a push-on red lead on the left front post (the post is much smaller than the two copper posts). The small post on the right front of the relay is empty. Have I mis-wired something? I'm including a pic of the new relay from the bottom so everyone can see the posts as they are configured. The two small posts on the front of the relay each have the letters S and I stamped above them, left to right. Any help would be appreciated. I want to get my son's truck back on the road so I can have my Expedition back again! Thanks in advance, ---rick:confused:

http://www.autozone.com/autozone/par...4_131140_9348_

The 4 post solenoid has an "S" and an "I" small post, it is also Grounded via mounting to fender, so that needs to be a clean good contact.
"S" wire goes to the key(ignition switch) it will have 12 volts when key is turned to START, and 0 volts in RUN or OFF, this wire, of course, closes the solenoid to activate the starter.

"I" post was used for the coil, coils will overheat if they run on 12 volts all the time, so in most older systems there would be a ballast resistor or "resistor wire" hooked to the "+" on the coil, this supplied the coil 7 to 8 volts which is fine for a good spark.
But on cold engines with choke on the spark may not be "hot" enough so the coil was given the full 12 volts at startup.
This 12 volts came from the "I" post which only has 12 volts when engine is cranking.
This 12 volt wire was moved to the starter motor post on some models because it does the same thing, coil gets 12 volts when starter is activated.

So make sure you are using the "S" post for the Key wire.

New ignition systems had the 12 volt to 8 volt built into the module so "I" post wasn't needed.


The other wires on the Battery solenoid post are the alternator wire(s) for charging and some times the power distribution wire for the fuse box.

The new solenoid could be bad, or solenoid is getting 12 volts on the Key wire from a short.
With hood open and unhook the coil wire, you want a no start, then see if you can get starter to stick on.
Pull the "S" wire and see if starter stops, if it does then that wire has 12 volts when it shouldn't.
It starter continues to crank with "S" wire unhooked then solenoid is sticking, take it back.


I re-read your original post, the 18 gauge black wire on the starter motor post should go directly to the "+" on the coil or remove it, it is on the wrong post.
Nothing would be on the starter motor post except starter motor and "+" on coil.
If it is a Black/orange wire then it is for the alternator, and goes on the battery wire post
Black/white wire was for power windows, and goes on the battery wire post

Starter relay - strange wiring colors on mine
 

Thanks, RonD. I'll do some wire tracing tomorrow to confirm the wire routing as you've described. To address some of the points made in your post, see below:

"The 4 post solenoid has an "S" and an "I" small post, it is also Grounded via mounting to fender, so that needs to be a clean good contact."
The grounding contact to the fender is clean and a good ground.

"S" wire goes to the key(ignition switch) it will have 12 volts when key is turned to START, and 0 volts in RUN or OFF, this wire, of course, closes the solenoid to activate the starter."
This wire, on my son's truck, is a red/blue wire and is the only one with a terminal small enough to fit on that post. I'll make sure it is on the correct post tomorrow.

"I" post was used for the coil, coils will overheat if they run on 12 volts all the time, so in most older systems there would be a ballast resistor or "resistor wire" hooked to the "+" on the coil, this supplied the coil 7 to 8 volts which is fine for a good spark.
But on cold engines with choke on the spark may not be "hot" enough so the coil was given the full 12 volts at startup.
This 12 volts came from the "I" post which only has 12 volts when engine is cranking.
This 12 volt wire was moved to the starter motor post on some models because it does the same thing, coil gets 12 volts when starter is activated."
I don't have any other wire terminals that are sized to fit the smaller post, other than the red/blue wire described above, so am I correct to assume this wire may have a larger wire terminal on it and would be on the starter wire post? This way, as you describe, it will only be a full 12v when the relay is switched on upon startup (therefore, would not always be hot)?

"So make sure you are using the "S" post for the Key wire."
First thing tomorrow.

"New ignition systems had the 12 volt to 8 volt built into the module so "I" post wasn't needed."
This may be the case on this truck as the original relay did not have a second, smaller post. I'll look in the morning.

"The other wires on the Battery solenoid post are the alternator wire(s) for charging and some times the power distribution wire for the fuse box."
Perhaps the power distribution wire you mention is the red fused link I have on this truck. In looking at the wiring diagrams I can't locate the red nor the orange fused links I have on this truck. They are definitely red and orange and not aged/cooked wire insulation as I can trace them into the protected portion of the harness and they are indeed red and orange. Again, I'll do some tracing tomorrow to find out where they go.

"The new solenoid could be bad, or solenoid is getting 12 volts on the Key wire from a short.
With hood open and unhook the coil wire, you want a no start, then see if you can get starter to stick on.
Pull the "S" wire and see if starter stops, if it does then that wire has 12 volts when it shouldn't.
It starter continues to crank with "S" wire unhooked then solenoid is sticking, take it back."
When you reference the "solenoid" are you talking about the relay on the inside fender? Is there not a starter solenoid ON the starter itself, or what some of us old guys call a bendix? May not be able to return the starter relay, bought it late last summer and am just not getting around to putting it on. That and the fact that they have a non-return policy for electrical components. For now, we'll hope that it is ok and deal with a return when we get to that bridge.

"I re-read your original post, the 18 gauge black wire on the starter motor post should go directly to the "+" on the coil or remove it, it is on the wrong post.
Nothing would be on the starter motor post except starter motor and "+" on coil.
If it is a Black/orange wire then it is for the alternator, and goes on the battery wire post
Black/white wire was for power windows, and goes on the battery wire."

Thanks again for all of your insight. Will report back tomorrow night when I know more. Will trace wires tomorrow to determine their origin/destination.

All of this due to his not being able to pass emissions one last time! His truck is an '84 and therefore, in the eyes of our state, a "classic". He can now get classic plates, never again (except for one last time) need be inspected for emissions, and never have to register again! Since he failed emissions this past summer he has been driving my Expedition while I ride one of my motorcycles. Since his truck was parked we have rebuilt the carburetor, replaced all of the rubber (vacuum lines, hoses, belts) under the hood, and cured the reason for not passing emissions by replacing the valve guide seals. Now to just get past this starter relay issue and he will be on the road. Don't worry, we did each of the above listed work one step at a time, making sure everything checked out ok before moving on to the next step on the project. ---rick

Solenoid is the term for a high current relay, but you are correct technically the fender mounted unit on the older Fords was a relay.
Solenoid term was used for the unit on a starter motor that passed the high amps to the starter motor but also pushed the drive gear out to engage flywheel.

If the current starter motor is a newer model and does have a solenoid on it then you will experience what you have now, a starter that will not disengage.

In that case the wiring would be custom not as per original diagrams.

The fender mounted relay would only be used to pass the smaller "S" wires 12v to the on starter solenoid.

So large "black" starter motor cable would be on the Battery post, so starter solenoid has direct battery connection.
Then a smaller wire from original "starter motor" post on "relay" to the small post on the starter motors solenoid.
So when key is moved to start, the fender relay closes and sends 12v to activate the solenoid on the starter motor.

Diagram here:
Adding a Remote Starter Solenoid to your Chevy, My Way

This is only IF the starter motor has a solenoid, older Ford starters did not

You just made me have an AHA moment!
 

RonD, thanks so much! As the subject line says, I just had a forehead slap AHA moment. My son does most of his own work and had just replaced his starter late last summer before all of this started. I'll need to crawl under his truck to see if there is a starter-mounted solenoid on his new starter. If so, I'll reroute the wires as indicated in your link.

Right now, will have to wait for the weather to warm up a bit. We got about 3" of snow last night (it's parked outside) and need to do some shoveling also. I may not get to this until tomorrow, which works out great as he has a day off tomorrow and can then watch/learn and assist me. I'll get it up on jack stands today.

checked, checked, and rechecked - still need help
 

Just came back inside after a frustrating morning/afternoon outside trying to find out why the truck won't start. Crawled underneath and was able to determine the starter has a solenoid-like bump but does not have the typical solenoid (with posts for battery connections and a wire to the ignition, as you described previously) like I am used to seeing on other vehicles I've worked on. The new starter he installed has a single connection point for the 10ga wire from the starter relay/solenoid on the fender. Checked the connection and it was clean and secure.

Went on the check the wiring on the relay to make sure it was consistent with your description. The one extra wire on the starter (large right post, as you are looking at it straight on) post I relocated to a ground point where the relay/solenoid attaches to the fender (also a good ground, clean and secure). That leaves only the starter wire on the right post.

The large left post has the hot wire from the positive terminal of the battery and the two fuse links I mentioned earlier (the orange fused link is connected to the dash lights as we were able to discern). The red fused link goes into the wiring harness and is connected to a relay of some sorts under the passenger-side kick panel, confirmed by connecting and disconnecting the wire from the hot side and listening for the relay to engage/disengage. This wire also is somehow the to one of three vacuum-type relays (just aft of the starter relay on the passenger fender) as you can feel the switch move when wire is connected/disconnected.

The red/blue wire on the "S" terminal feeds into a wire harness that snakes around the front of the engine bay and in front of the radiator and eventually feeds into a grommet on the firewall that enters the dash. This wire, as you described, is activated by the "start" function on the keyed ignition.

Now, my confusion/frustration related to the starter relay. I took my multimeter and tested all points on the starter relay and the battery. The battery is solid and reads a good 12.62 volts. Helps to alleviate a nagging suspicion that maybe the battery was weak and not holding a sufficient charge. Performed a drawdown test and it came out fine.

The terminals on the starter relay:
The hot side (left large post) reads identical to the battery - 12.6v;
The 's' terminal on the front of the relay reads 12.6 all of the time, with the exception of when the key is engaged and it temporarily drops to around 11.8 or so;

and now for the confusing part (for me, anyway)
The starter post (large post on right of relay) reads a consistent 12.6 when the key is off, dropping to almost 0.0v when the key is turned to the 'start' position !? I had assumed, perhaps incorrectly, that this post would be a 'dead' post until the key was turned to the 'start' position, then sending the full 12.6v to the starter. I crawled back underneath the truck to determine if the starter was also getting 12.6v. It was, yet it was not turning as I would have expected. I removed the starter to check to see if the gear may have been bound up but it spins freely by hand.

When the key is turned to the 'start' position, and everything is hooked up, the relay/solenoid engages/disengages much like a solenoid does when your battery is too weak to start the engine. I'm coming up against a wall here and am looking for some advice. I am very experienced mechanically but electrical issues have always befuddled me. Is there a way to check the resistance on the starter relay to find out if the part is bad? TIA, ---rick

That reads like the correct starter for that year, no solenoid.

The "S" wire should not have 12v except when key is in START position.
That where the issue is.

Remove it(you should hear relay "click" open) and test the post with starter motor wire, should be 0 volts now.

Starter motor may be bad now if its been on all the time, you can use jumper cable or wire from battery to starter motor wire on relay to see if motor works.
MAKE SURE trans is in Neutral or Park.

Why the "S" wire has 12v all the time:
The key switch moves an "actuator" bar that then slides the ignition switch into its various positions: ACC, OFF, RUN, START
If key switch gets worn then it can leave ignition switch in the wrong position.
Does the key switch feel ok?

On manual transmissions there is often a neutral safety switch(NSS) on the clutch pedal, not sure on the '84 but later models had it clamped to the push rod that goes into the clutch master cylinder, so when you pushed the clutch in it would "click" closed(like a brake light switch) and pass power.
The power it passed is the 12v "S" wire voltage.

So the "S" pathway is:
Battery---------ignition switch------------NSS-------------relay on fender

Reason I mention this is that on older trucks that have been worked on over the years, some people choose to hot wire the NSS switch which is not great but it's their truck...at that time.
How they hot wire is the concern, it is just two wires but if left exposed it could get shorted out.

You can also pull fuses while checking the "S" wire for 12v, maybe narrow down the circuit that is feeding it 12volts.



EDIT:
oops, misread your info

Relay is bad
Remove all wires and test relay
"S" post would read as a ground, not as having 12v
"S" post is just a coiled wire around a metal cylinder that is connected at the other end to the relay chassis, a ground, when you send 12 volts thru it it changes to an electro-magnet and pulls the relay closed sending battery power to starter motor post.

"S" post and ground should read connected with a few OHMS
Battery post and "S" post should read no connection, infinite OHMs, but it reads like they are connected

Tasks for tomorrow:
1. check to see if starter is working ok using jumper cable;
2. remove wires/cables from starter relay and check for proper function;
3. visit Autozone and replace as necessary.

The NSS (yes, it is a manual tranny) is intact and working as designed. The ignition switch on the steering column has positive detentes at each position and has always functioned properly so confident it is ok. Will check the relay for proper function late tomorrow morning and get back with results.

Yes, mis-read your post that the "S" wire had 12v all the time, not that the S "POST" had 12v all the time.

starter is good
 

Just tested the starter by jumpering it directly from the battery, bypassing the starter relay on the fender. Some hesitation at first and then turned engine over without any problems.

Tested the starter relay for continuity. Ground (the top of the relay on the attaching bracket) to 's' post, no wires connected, reads about 3.6 ohms. All other readings, ground to BAT post, ground to Starter post, 's' post to (each) BAT and Starter post are all an infinite reading (reads as a 1., all the way to the left of the screen, on my Craftsman multimeter). If I am correct, I believe that means that the relay is bad and needs replaced. I will take it to Autozone for a replacement relay this afternoon and report back. In the mean time, I have a known good relay, identical to the original, on my '88 Ranger that I am swapping out short term to confirm my assumption that the relay is bad. Will swap in the new one later this afternoon.

Will report back this evening. ---rick

Relay actually reads like it is good.

"S" to ground should be low ohms.

And no other posts should have continuity to each other.

I would install that relay so it is grounded then touch 12v(battery cable) to "S" post, you should hear the relay "click", no click then replace.

Get a 3 post relay if you replace

swapped out relay
 

Swapped out the questionable relay I have been struggling with for a known good one from my '88 Ranger. Why I didn't think to do this two days ago escapes me. Once the relay from the '88 was installed it works great. No problem turning over, works how and when it should. The one off of the '88 is a 3-post relay and installed it just like the old one (pre-new Autozone relay). Put the Autozone replacement relay on my '88 and have the same problem/behaviour there that I had on my son's '84 Ranger.

I know your message indicates, based on my testing and reporting of the continuity readings, that the relay is good but for some reason it is just refuses to behave like it should when installed. Just to be sure I am going to return it this evening to the local Autozone and get a new one, preferably a three post relay. I'll let the guys at Autozone go through there own bench testing to find the fault.

Now, I have a new problem which I will post in a new thread to avoid hijacking my own thread and to keep threads on topic. This time it is the carb not getting any fuel...

Special thanks go out to RonD for all of your help, patience, and willingness to share your knowledge and experience. Maybe next time I ride through BC I can stop in and buy you a beverage of your choice. ---rick

follow-up
 

As a follow-up to the thread and to close it out, I wanted to let everyone know that the guys at Autozone (the ones there today and not last evening, the ones last evening scratched their heads on how to even test the relay) were able to duplicate the fault in the relay. Won't know for sure unless they tear the old one apart, which they say they aren't allowed to do, but it seems to have been an intermittent fault inside the relay. New relay installed today, replaced my old/good one into the '88 Ranger, everything working as designed.

Thanks again go out to RonD for all of your information and advice. This thing really had my head spinning.

Thank you for the comments.


As consumers we are our own worst enemy these days, we wanted less expensive parts and we got them.
"Be careful what you wish for..................."

So we now have to deal with the new axiom:
"new no longer means it works, new now means it has never been tested"

To make parts less expensive manufacturers removed all but basic Quality Control, in some cases they added better warranty, but that still leaves us as their "new" quality control department workers, and unpaid workers at that, lol.
And no dental plan either