Join Date: Dec 2002
Location: Norton Shores, MI
Feedback Score: 0 reviews
I say batteries too, and put a meter on the alt, when running it should put out around 14.4. If the batteries are newer it could be the alt. It kind of goes hand in hand, I have had 3 alts in 270k and 10 years, I quit buying the NAPA crap and went with a Ford alt, it has lasted a long time now, longer than the others. When the alt goes it is weak and the batteries don't charge, if the batteries are weak the alt works overtime and goes south. The last would be the starter, if it is going south it will crank slow. Start at the alt with the meter, if it is pumping out 14.4 it would be the batteries, get the Interstate with 1000 cold cranking amps, I have had good luck with mine. Also keep an eye on the block heater plug end, they go bad and can short out and burn the truck down. Once I plugged mine in and it sparked big time, I replaced it with a Marinco plug that mounts in the bumper and eliminated the plug end with a waterproof housing with the male end protected and fixed so it is not being stressed and moved around. Heck mine did not even work due to a broken wire in the plug end. A way to tell if it is working is to feel the ext cord, it will be warm if it is drawing current. Also an ohm reading across the plug ends will tell if it is open (broken) or show about 15 to 20 ohms of resistance, which means it is good. The wire causes resistance to the current, no resistance means nothing is flowing thru the wire because it is open....or broken. Good luck.
2003 7.3 Excursion Limited Ultimate, Mineral Grey Metalic. DVD, Limited Slip, Badged, Cab Lights, Magnaflow, Thule Rack, Top Gun Bumper, 3" Lift, T Prodigy, Air Bags, Edge Programer, XM Radio, Extreme sound system. PIAA Lights, Toyo 325/60/18s on Chrome Alum rims.