so im hopeing to have my problem answered about my truck, i have a 1990 d250 cummins




im 17 ill be 18 this sunday, (and am located in western nortch carolina)but iv been working on cars for awhile mainly my 86 fiero gt daily driver, and modding my dads 98 vette, anyways my d250 has a battery drain or something my battery chargers show it as fully charged, the eletrical checks out according to advance auto, alternator is a few thousand miles old, tried about 8 different voltage regulators in the past 3 months, all bwd(advance auto) except for a napa which is the same as bwd, and now im tryn a wells from rock auto along with a starter relay and a new interstate battery...... the only way i can get the truck started is to leave a v8 grand marquis hooked up to it with jumper cables for about half an hour, if it sets a few hours and i go back to start it it will try to start about every 4th turn of a key but doesnt fire. and when it is runnning the battery gauge shows that its not fully charged and its running off the battery, if i ground the green wire on the voltage regulator plug like i seen on a forum the battery gauge pegs at 18 volts

any input is appreciated

edit: just noticed that if i keep the key turned to start for about 5 to 7 seconds it eventually fires, but some times this kills the battery before it starts

 

Sounds like you may have a wire shorting on you. I have never had to crank my truck more than 2 or 3 seconds. Electrical problems can drive you crazy. Best i can suggest is start looking where vibration could have rubbed through the insulation on your 12v constant wires. Such as the firewall. Good luck

 

yeah thats what my dad told me but i was hopeing it might be some little part.... he thought it could of been the starter since this truck usually starts right up within about 2 seconds

---AutoMerged DoublePost---

so i went to napa to return something and i asked them about my truck sine theyt are quite knowledgeable, they told me to check and see if theres a drain, an turns out theres an 8 volt drain with the key off. napa thinks its my alternator and told me that the avg life span is about 6 yrs on that alternator since its got a napa alternator on it

---AutoMerged DoublePost---

okay so i got the alternator checked, the entire charging system is good and all the wiring is that i can find, and and with the alt removed i have a 10 volt drain

 

i have the same bull s**t going on in my 1993 w250. i have to charge the battery for about 45 min to start it and itll only start the next day if i drive it enough the day before. been through 4 batteries since december! god i hate 1st gen wiring

 

i know how you feel, but i used a multimeter to check the drain so i kept pulling fuses til the drain went away, i think there may be a problem in my interior wiring

 

Welcome to DB, nice truckElectricial gremlins suck

 

thanks the only problems it has is the odometer dont work, this electrical problem, and for some reason the brakes lock up super easy.. the truck was inherited 10 yrs ago, and never really got driven til i got my license, now that im driving it im having to fix the problems that have been ignored

 

so i got the drain fixed i simple took the fuse out for now, i think its in the radio wiring some wheres, but it still is having problems cranking

 

Welcome to the wonderful world of owning a first gen! Electrical demons are a big problem with these old trucks. My driver side window wont roll down anymore, my windshield wipers work when they want to, my odometer doesnt work and so on.... Nice truck btw and welcome to DB

 

i may have found my draw finally! my under hood light doesnt shut off when hood is latched and it was unplugged by previous owner so i hope it is that!