Dont know if this is really the place, but its a 75 F100 with a 302 EFI HO swap.

Intro Thread

The motor came from a Lincoln Mark VII. Right now Ive got the voltage regulator wired correctly on 3 out of the 4 leads. The fourth one maked *I* is wired to the starter solenoid with an inline resistor to excite the regulator upon start up. After startup, this particular wire sees no power. Upon start up, the alternator is working just fine.

After driving the truck for a bit the alternator kicks off, and im wondering if this wire needs power all the time. Im not using the original F100 harness, but the Mark VII harness and cannot for the life of me figure out this thing. Any help would be appreciated.

Thanks,
P@

 

That *I* stands for ignition.

It only gets power during start-up.

What do you mean Kicks-off ?

I've never seen an alternator stop turning while the engine is running

Do you actually mean the voltage regulator send out less power ?

 

By *kicking off* I mean the voltage regulator tells the alternator to stop sending voltage to the system after running for a while and therefore im running strictly off the battery. This is only after ive been running the motor for a bit, on startup the alternator is putting out a consistant 14.4V.

Ive had the alternator checked at checker/autozone and they tell me its a good alternator. Ive picked up a new voltage regulator as well to see if that might be my issue...

Im basing my wiring off of page 7 and 8 of the painless diagrams...

http://www.painlesswiring.com/Manuals/90526Manual.pdf

Ill be trying the alternate method as outlined in section 7.1.7, and probably put in a different battery as well.

 

The voltage regulator shuts the voltage down, not the alternator.

The alternator continues to produce power as the engine is running.


The situation as you describe it sounds like the NORMAL operation of the charging system to me.


Have you seen this ?

http://www.humanspeakers.com/ford/charging.htm

 

Thats a great article thanks for the link...

So get this...I also did a full field test on the alternator by jumping *F* and *A*
at the harness of the VR at multiple times.

The first test was done after a short drive. Upon startup I was reading 14.5V with the VR connected (alt working)...bout 1/2 mile drive later the voltage dropped to 12.5V or so. Telling me the alternator wasnt putting out anything. So i stopped, jumped the harness to do a full field test, and sure enough, i was only reading the battery charge with the motor running.

So, after getting back to the shop, I let the motor cool down for an hour or so, and did the test again....low and behold, I was then getting full voltage from the alternator, like 17+V

Bad alternator you think? Its like its getting hot and crapping out, or maybe its on its last leg...

Ill have to get another alternator tonight and see if that truly is the problem, the down side, the parts store is an hour drive for me..

 

Dude, sorry I have nothing to offer you, but I commend you on a 5.0 HO swap in your '73-79 Ford truck!
Do you have engine compartment pics to show? Sounds like a cool deal.
Mark

 

yeah, here are some...its a work truck just so you know

http://www.customsteel.com/images/F100/IMG_2892.jpg
http://www.customsteel.com/images/F100/IMG_2894.jpg
http://www.customsteel.com/images/F100/IMG_2895.jpg
http://www.customsteel.com/images/F100/IMG_2896.jpg

 

Hey, that's the stuff, man! I recognize the Mark VII valve covers!
That is too cool. My '78 has the same factory stripe pattern as your truck, as you can see in my gallery, only different colors.
That truck has potential, beyond a work truck!
How is the power from the 5.0? I'm sure it's better than a stock 302 from those years, and better on gas, and more powerful? What mods did you have to do to get it all to fit? Dis you also take the AOD?
Mark

 

yes i would like to know as well i'am doing the same conversion to my 1993 flairside.

 

Well just an update, it was the alternator after all, put in a new one, along with a new voltage regulator and the charging isses are all solved.

As for the difference between the motors, the old carb'd 302 was in very bad shape before we pulled it, but the new motor pulls stong and runs really smooth, we havent driven it around enough to get an accurate milage reading. The thing I really like is the ability to take the rpm's up higher during shifting and reducing the stress on the tranny.

As for mods to the truck, aside from cutting a new hole in the firewall to route the harness into the cab, there were no structural mods done, the motor bolted right into the frame. The list of *other things considered*....well here you go.
I had the Mark VII donor car at my disposal and after spending 4 days isolating the necessary items on the wiring harness, and a day pulling the motor, I used it complete, including the fan.

-302 EFI HO Motor
-Fuel tank, intank pump, and sender from a 85 F150 (used)
-Inline High pressure fuel pump from 85 F150 (new)
-High pressure fuel line for feed and return
-New Motor mounts
-Old 302 starter will work, same with flywheel, bell housing and tranny (we didnt use the auto tranny from the Mark VII)
-Old headers from 302 truck motor, or shorty truck headers will work, the car headers interferr with the clutch linkage
-Youll need a 2.5" pipe of some sorts for the intake, with couplings and filter.
-Weld in two O2 bungs onto the exhaust for the O2 sensors.
-Fan shroud from an early 80's F150
-Radiator hose outlet (t-stat housing) from 302 EFI truck motor.
-Relocate the belt tensioner on the PS bracket and use a shorter belt for the serpentine system (were gonna convert to PS soon and will reroute the belt once again and make the alt adjstable to tighten the belt)
-EGR stuff I threw in the trash...
-Modified the Mark VII gas pedal to bolt into the truck to use the throttle cable

I think thats about it, but if your really wanting to do this....do some reading here

http://fordfuelinjection.com/?p=1

I found this after the swap, but good reading and VERY informative. good luck and thanks for the help here so far.

 

Wow, that sounds awesome! I haven't seen an efi anything in a 73-79 truck! I would like to see someone come up with a 4.6 or 5.4 swap now!
Mark