ok, so i’ve had this 1985 S-10 blazer no for twomonths, and recently i put a brand spankin’ new ign. module into it and it started that day. 3 days later, i go out to start so i can move her to wash her, and it won’t start. theres no battery and i have to jump her to start her, but that’s never given me any problems before. and to top it off, my ign. is stuck at run and i can’t put my key in, but it still turns to start. is that an ign. switch? if so, can anybody tell me how to fix my bettie jr.? i DESPERATELY need her going for college in september. thank ya’ll.
You must’ve really wanted an Old Blazer for a project, or because you wanted a vintage ride, because you wouldn’t buy a 24 year-old ride otherwise. I haven’t seen this thing and I have no idea what the mileage is, but get used to things like this happening on a vehicle this old-especially a Blazer.
As for your problem there are two possible problems that come to mind based on your somewhat difficult to understand story. Either you are running the battery down because you’re leaving the ignition on 24/7 or you have a constant voltage drain. To check to see if there is something draining the battery while the key is off, remove the positive battery terminal, and with an ammeter, measure to see if there is any current flowing from the battery to the cable (or, for more accuracy, use a low-amp induction probe ammeter to measure current flow through the battery cables.) If there is anything more than a couple of milliamps, try removing fuses one at a time to see if you can identify the circuit that is causing the drain. If this pins down a problem, a little more sleuthing through the offending circuit should tell you what needs to be done.
If there is no drain showing with the above test, the charging system is suspect. Try measuring the voltage at the alternator output terminal and battery pos terminal with all utilities (headlights, rear window heater, fan etc.) on high. Any difference in reading indicates a poor connection somewhere in the red cable from the alternator. Don’t assume that a crimp connection of a terminal on the cable is good. Corrosion can introduce enough resistance to prevent proper (any?) charging when there is a significant load on the system (cold, dark, wet/snowy winter evenings).
P.S. If you’re going to college soon-here’s a quick tip: capitalize the beginning of every sentence, use one space between sentences, and write in complete sentences. It’ll save you some trouble.
Are you saying there is no battery installed in the truck? Running a vehicle without a battery can fry sensitive electronics, including brand spankin’ new ignition modules.