alternator on my 67 f-100

yogi_pahl · Post by **yogi_pahl** » Mon Sep 01, 2008 1:29 pm

Went to start it today and got the "ERRRR" sound of a dead battery., didn't have a good battery when i got it. Jumped it off started like normal, let it run for 10 mints. Turned it off counted to 60 and truned it back on. Still had the same "ERRRR" sound if i never charge it. My alternator must be ok if the battery is dead but the engine still runs it just wont charge. I did some stuff behind the gauges the other day. I will be cleaning all the wires on the alt latter today. Now my questions.

1. Can i test the alternator with just a volt meter(can't go to the parts store till tomorrow to have it checked)

2. How do i test the voltage regulator?

3.Anything behind the dash i could have messed up. I only see one wire the splits off. One goes to the switch and the other to the ATL light. With works i just don't have a bulb in it right now.

BTW it not the stock engine it's a 351c but looks to have the stock voltage regulator

seattle67 · Post by **seattle67** » Mon Sep 01, 2008 4:05 pm

With your engine off, check your battery voltage. Then get the truck started and check the voltage again at the battery. You should see an increase in voltage, something in the range of 13.5 to 14.5 volts would indicate the alternator is working.

One quick thing, have you cleaned your battery terminal connections?

mljjones67 · Post by **mljjones67** » Mon Sep 01, 2008 4:11 pm

Drop an aspirin in the battery if that ends up not holding a charge.

rjewkes · Post by **rjewkes** » Mon Sep 01, 2008 6:45 pm

sounds like a battery not taking a charge or if i remmber right on dummy ligh equiped trucks the light has to work in order to charge. so maybe a dead bulb would cuase a no charge situation?

think the light coming on excites the charging system.

seattle67 · Post by **seattle67** » Mon Sep 01, 2008 8:00 pm

rjewkes wrote:sounds like a battery not taking a charge or if i remmber right on dummy ligh equiped trucks the light has to work in order to charge. so maybe a dead bulb would cuase a no charge situation?

think the light coming on excites the charging system.

You are absolutely correct Robert, on some charging systems the light is needed for the system to work, but I believe that on our trucks, Ford put a 15 ohm resistor in parallel with the light to fix that problem. Please, if someone knows that to be incorrect speak up.

yogi_pahl · Post by **yogi_pahl** » Mon Sep 01, 2008 8:08 pm

Thinks guys. I think rjewkes and Blue Oval Fanatic you are right. I took off the alt and was going to clean the all the ends off but they looked fine as can be, Checked all the wires on the voltage regulator every thing looked fine. Don't know what i was looking for but it looked good to me

. It all looked good in the bay so went under the dash to see if i could find anything threw in a bulb for the ATL light jumped it off and it's fine now. Might have been a loss wire or the bulb has to be in to make it work I say it was the bulb.

Dragon · Post by **Dragon** » Sun Sep 14, 2008 2:03 pm

seattle67 wrote: Ford put a 15 ohm resistor in parallel with the light to fix that problem. Please, if someone knows that to be incorrect speak up.

Yep here from the 71 manuals

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alternator on my 67 f-100

alternator on my 67 f-100

re: alternator on my 67 f-100