this is a bone stock 1994 f-250 with a 351 it has the the newer style 95 amp alternator. the problem im having is that this truck is eating alternators very badly im talking 4 alternators in 1 day. i have checked the fuses 18 and 15 and not blown, battery ground connections at the block was tight not caroded and pulled it off checked the ohns in the cable come back as 0.2 ohms, checked fuseable links in alt wiring harnes that was good no corrosion in or out of it was intacked yes i slit the rubber protector open carefully inspected the wire. and inspected the alt plug in it was good no broken wires again all clean with very low resistance. i checked the hot cables at the battery little red wire for the s terminal on the starter has very low resistance and along with the main cable to the starter is all good so basicly all wires are in good shape. battery is brandnew also. the first alternator was purchased from autozone baught the cheap one and lasted 3 mnths replaced it with another it lasted 40 min had become very hot and just quit charging. 3 lasted 20 min and was the upgrade from the cheaper one and did same exact thing as number 2. put number 4 last one didnt even try to charge at all just like all others tested bad after having it tested. only thing i can guess is i either have realy bad luck buying bad alt or have a problem somewhere. this happened after i changed the gauge cluster with a tach. i removed the this cluster and installed the old cluster still had the same problem.

 

If it started after you changed out the gauges, then you've done something when you were changing the gauges. What that was... who really knows. My advice would be to back track everything you had to do to replace the gauges and make sure you have everything hooked up correctly.

 

well to change the gauges all i had to was just simply unplug the harnes behind the cluster 2 big plugs and 1 small plug in center of cluster i did check all of that also no burned or broken wires and plugs are stilll good not broken at all and all gauges work good and no blown fuses. the amp gauge just reads what the out put is in the system it doesnt send any data back to charge or not charge. also this gauge cluster sends information to e.c.m. from speed odometer and that is also tied into the transmission for the shifting and torque converter lock up is all passed through this speed o and that hasnt had any issues at all

 

WOW, 4 alt. in one day!! I highly doubt changing the cluster has anything to do with it!
Try getting the alternator from another store are maybe a scrap yard.

 

i just got a used alt tested and said it actuely over charging a hair then what it should be but ill use it any way just to check it out see if this one cooks as the last one cooked in 10 seconds flat lol i will try that and see what happens. thank you all for your help