alternater

[newb70f250camper]

what is the quickest and cheepest way to check an alternator, some one said that when truck is rinning take of positive cable if truck dies the alternator is bad? is this correct???

[fordman]

yes if the truck is running and the battery is low pulling the cable off will kill the enigne.

[Thunderfoot]

That will only tell you that you aren't charging, it wont tell you if it is the alternator or the Voltage Regulator or the fusible link to the alternator... You can do the full-field test listed here http://www.fordification.com/charging.htm to check if it is the voltage regulator causing the problem or pull the alternator off and take it to your local parts store and have them check it out. You need a test light or voltage meter to check the wire to see if the fusible link is blown.

[newb70f250camper]

need help with the wiring on this truck wiring for altenator and regulator. i think im missing a wire and cannot read wiring diagrams on the websight very well. have some pics can any one help

100_2875.JPG

[newb70f250camper]

heres some more

100_2873.JPG

[newb70f250camper]

two more, any help would be very appreciated

[Thunderfoot]

You have all the same wires hooked up that mine do, the wire diagrams don't cover all the different wiring options... That Voltage Regulator you have is the old point style so wouldn't be surprised if its age has gotten to it. I would have the alternator checked out at the parts store beings you got it about off anyway (they usually do it for free) and if it is good try a different Voltage Regulator.
To check the fusible link to the alternator just check that you have voltage on the BAT terminal on the alternator with the battery hooked up. (engine not running) If you have voltage there then the cable is good.
Also, one more check: be sure that Green-red stripped wire going to the voltage regulator has power on it with the key on in the Run position.

[newb70f250camper]

the truck has electonic ignition on it, it is a hybrid, it has a 1976 pointless distibutor with a gm hei ignition module because the ford ignition module went bad and it was cheeper and easyer to wire. the truck runs fine, i let it sit for a week and run it on the weekend, by sat. night the battery is dead. can i use the voltage regulater that is electro magnetic or do i have to use the kind that i have on it .

[fordman]

if it runs down the battery in a week it is probably some sort of drain onthe battery when its shut off. remove the negative battery cable and put a test light inbetweenthe negative post and thenegative battery cable. if the light comes on you either have smoething on like the doem light or radio. or if everthing is shut off . it is a short in the system draining the battery. to find the short now. remove one fuse at a time. until the light goes off. once the light goes off yo uknow which circut the drain is on.then start chasing that circut until you finsd the drain. eiterh that above or thebattery is gettign weak and old and just wont hold up any more. have the battery tested just in case tomake sure it isnt getting close to quitting.