Pulled part of the dash apart and noticed the ignition switch was ziptied together. The plastic pieces on the sides are broke and it's pretty loose. I imagine that would cause a no start.


-Destin

 

?? You found the problem in the regulator correct? The "S" terminal was broke off? Have you fixed that yet?

 

The piece was broken but it looked burnt. I ordered a regulator online along with a new set of door locks and ignition.

I have a msd distributor and coil. That shouldn't play into anything should it?

-Destin

 

If everything else on the truck worked, and it ran too, then I believe the charging problem was the regulator. Even though the ignition switch sounds like it needed replacing, if everything else worked, it was probably working ok.

 

Thanks for the follow-up Franklin2.

 

Installed the new ignition and heavy duty voltage regulator. Now I have to take the heads off to have a valve job done.

Thanks for all the help Franklin2 and FMC400!

-Destin

 

franlin 2 i dont know if your still on here but i had a couple questions about what you posted on here. i have a 78 100 and am having the same problems pretty much. i got a new alternator put it on and still nothing. im new to alternators so i need some help.

there isnt suposed to be an actual ground wire on it cause it grounds through the block right?

and you said to check the volts going to the converter while the key was in run. i did that and got .5 volts going to the s wire and 1 volt to the I wire. is that all im suposed to have?

i did the test with taking the f wire straight to the battery and it only went up to about 13 from just under 12?

any help is greatly appretiated thanks!

 

It may have only went to 13v if you have the engine idle set really low. The voltage jumping up means the alternator is putting out something.

You have wires going to the "I" terminal of the regulator correct? So I am going to assume you do not have factory dash gauges, instead you have a "GEN" light in the dash. When you turn the key to run, but do not start the engine, does the "GEN" light glow?

 

ya i put the f wire on the battery and went and reved it and it still didnt go over 13v. but no i dont even have the gauges in there i made my own dash and put my own gauges in it. so can i just cut that wire off?

 

If you have modified the wiring in the dash, then you need to hunt down the old wire going to the "I" terminal and hook it back up to spot that has 12v when the key is in run. Better yet, go to the store and get a 12v dash light(one that has two wires) drill a hole in your dash and install it. Run one wire to a key on power source, and run the other side of the bulb out to the "I" terminal. This is what triggers the charging to system to come "online" and start charging.

If you want to test this first, hook the alternator and the regulator all back up, and put your meter on the battery. Before you plug the regulator back in, scrape a little bit of the insulation off the "I" wire. Get the engine running, and then take your jumper wire and touch the battery + and the "I" wire (with the regulator plugged in and the alternator hooked up). If the "I" wire and the dash wiring is your problem, you will see the voltage jump up to 13v when you put 12v on the "I" wire.

If you get it all figured out, and you are still worried about the 13v, take the alternator down to the store and let them test it. It may test ok, and you may find the 13v output is enough to keep the battery charged. 13.8v is usually considered the minimum, and that may be a difference in your meter.

 

Just came across this while looking for an answer to my Bronco II battery charging problem.
THANK YOU - for explaining in detail the alternator check and the meaning of the connections.
I replaced my alternator and still don't seem to have a high charge rate for a 75 amp unit. I am going to use the knowledge you have provided here and see what I can come up with.