The never ending discussion about my'85 F150 continues...
I installed a 351w into my 4x4 F150, replacing the I6/300.

The donor engine had the wires cut at the alternator. The colors don't match what came with the truck harness. I did some educated guessing and now I'm having problems.

The new alternator is a 60a. When I start the truck, the starter does not disengage. The stator connection is disconnected/cut. I believe I have the fatter threaded connector connected correctly. The smaller threaded connection is a plug on.

If I turn the ignition key on and disconnect the little red wire from the starter solenoid I can jump the solenoid and start it. However, it is not charging. I swapped the old 40a back in and get the same symptoms. Everything worked on both engines prior to the engine swap so I'm sure I hooked something up wrong.

I am at wits end as this is the last thing to accomplish to get this truck on the road. What I would really like to know is can I bypass the wires on the alternator with alligator clips and make direct connections to do some tests? If so what do I clip to what?

I would like to verify what each connection goes to on the back of the alternator and possibly if anyone knows the colors.

Thanks a million guys.
Rick

 

[QUOTE]Originally posted by rleeds
The never ending discussion about my'85 F150 continues...
I installed a 351w into my 4x4 F150, replacing the I6/300.

The donor engine had the wires cut at the alternator. The colors don't match what came with the truck harness. I did some educated guessing and now I'm having problems.

The new alternator is a 60a.
When I start the truck, the starter does not disengage.

First Off :
The starting circuit and charging circuit are two different systems and are not related except for sharing a power connector at the starter solenoid.


You also didn't say if it was a side or rear terminal alternator




The stator connection is disconnected/cut.
Small wire supplies a small amount of power to the electric choke


I believe I have the fatter threaded connector connected correctly.

to the Big red terminal


The smaller threaded connection is a plug on.

That would be the Field wire that goes to the Voltage reg


If I turn the ignition key on and disconnect the little red wire from the starter solenoid I can jump the solenoid and start it.

That little red/another color is for the starter to engage with the key


However, it is not charging.

The battery gets its re-charge from the Big Wire that goes to the Red connector on alternator and attaches to the big lug on the starter solenoid

Here is a diagram for you to view.

I'll be back with another alt virew shortly.






Okay I'm back,
Here is a photo of the Rear Terminal alternator.
Is this what it looks like ?

 

Thanks for all the info Mil1ion.

It is a rear terminal alternator. The only reason I thought the starter issue and the alternator issue might be related is that the problem started at the same time. Thought I might have crossed something during the reinstall.

I will wire according to your instructions - thanks.

But what about the starter not disengaging when the starting the truck with the key? As I said, if I jump the solenoid, it will start without sticking. If I use the key, it won't disengage.

It doesn't seem likely that the ignition switch/key would go at the same time as the alternator. Could I have shorted something?

I think I'm losing it!

Anyway, thanks again for your help.

 

That's usually a ignition switch problem.

Do you leave the sure off the terminal once it is running?

Try this > Disconnect the wire to that terminal like you say you do

Now turn the key to the RUN position
and put a test light to the wire connector to see if there is voltage present.
If there is voltage present ,the problem is the ignition switch keeping power to that wire.

The power to that wire should cease when going from Key Start position to the Key RUN position

 

How many small terminals do you have on your starter relay?

Are you using the six cylinder wiring?

Are you using the original six cylinder starter relay?

Some starter relays have two small terminals. If you get these mixed up, your problem will happen. If the original six cylinder wiring had a two terminal relay, and now you have a one terminal relay, you may have hooked the wrong small wire up. I think it should be red/lightblue to the starter relay, but I am not sure. Do the test Dennis recommended with the test light, and if it stays on, look around for another wire you may have missed that is only hot with the key in start.

 

Starter relay is the same as the starter solenoid? If so, there are 2 small plugs, its from the original 6 cyl. and I'm plugged into the left of the two. I tried the test and it looked like the the ignition switch. I changed it but get the same problem. Again, if I jump the starter solenoid the starter acts normal.

Can something bad happen if I plug into the other of the two terminals on the solenoid?

P.S. I got the alternator all up and charging - Yeah Team!!
Does the stator line have to be connected? Should it be looped. I do not have an electric choke.

Thanks again all.
Rick

 

If you have 2 terminals there should be an ( I ) beside one and a ( S ) beside the other.

The red/ wire sparky mentions should go to the S terminal.

S is for Start

I is for Ignition > On start up ONLY ,this circuit send 12 volts to the coil for easier starting.

Excellent.... about charging now !

Name the colours of wires you have for the alternator?
I was sure one went to the stator.

It sounds like you have run out of wires .....right ?

 

I do have the wire for the stator & electric choke. I believe I don't have an electric choke on the carb. I'll double check. If I don't have an electric choke, does the stator wire even have to be connected to the alternator? Someone told me that he thought it might just need to be looped back to the alternator.

 

Yep, Some people just tape up the choke end and secure it.

 

Well, I think it's the solenoid. Now it intermittenly sticks. I have to leave the terminal wire off as it inconsistantly disengages the starter. Sometimes I can start it just by touching the wire to the solenoid; sometimes I can start it by plugging it in and turning the key. Sometimes when I turn the key, the starter will stick and I have to unplug the terminal wire. So now I just leave the terminal wire off and jump the solenoid (keeps me from having to run around and unplug the terminal wire to prevent the starter from burning out).

Does it make sense that the solenoid is sticking?

Thanks again all.
Rick

 

I am a man of constant sorrow...

I changed the solenoid and it still sticks. I guess I'll put in a new starter. Maybe the armature is intermittenly sticking. Doesn't make a lot of sense but I've changed everything else.
I put in new:
Voltage Regulator
Starter Solenoid
Ignition Switch
Alternator
Ignition module

I know some of these aren't related to starting but are here just for info.

Hopefully the starter will be it.

Adios for now; I'm headed under the truck,
Rick

 

Does life get any crazier?

I replaced starter with a new/rebuilt from the autopart store. I have yet to take the old one back to see if it tests bad.

I no longer have the starter staying engaged problem. Cool huh? Just when I thought it was cool, I was taking a test drive and the starter kicked on while I was driving!!!!

What the !@#*???? Never had that happen in any vehicle before. New ignition switch, new solenoid, new starter. What else could it be? Could the key be sticky? Doesn't feel like it. When I was having 'not disengaging' problem, I turned the key back clear up until the truck turned off to see if the starter would disengage and it didn't disengage until the truck was turned all the way off. On the test drive, when the starter kicked in, I turned the truck off and roll started it while I was still moving and the starter disengaged.

Besides the fact that God doesn't want me to drive my truck, what gives??!

Thanks,
Rick

 

New thought -

When I put the 351w in to replace the 6/300, we accidentally put in the shield from the automatic transmission/Bronco that the engine came out of. Could it be that the shield is a different thickness, acting as it's own shim and misaligning the starter? I did have to trim off some of the shield around the starter hole to keep it from rubbing the flywheel.

If that isn't it, I don't what could be wrong with the starter and possibly the solenoid. I'm dying over here.

Hopeless in Omaha,
Rick

 

The only way to get the starter to start turning electrically is to close the starter relay by putting 12 volts to its "S" terminal.
Well you can jump the 2 large teminals on the relay together but you should be able to see if something is connecting those together externally
Possibly you have a 12 volt wire that is intermittently touching the wire that feed the "S" terminal.
If so congratulations you have one of the hardest electrical problems to solve....intermittent ones

 

If you can, Take the starter back !

Sparky is correct, The ONLY way that starter can fire up is with electrical current travelling through the red/blue wire to the *S* terminal.

This means.
You have to trace this wire back to the ignition switch.

I still think it is the switch not the tumbler.

That is your mission if you choose to accept it.

This message will not destruct in 5 seconds

So.....Go after this baby.

I just bet the Ignition switch or the rod to it is wonky.