ok all, [I REALLY NEED SOME HELP COLOR="Red"][/COLOR]. First off, I couldn't get my mobile to pull my last question over, which is a really good start to this question( actually it's kinda the same, so if i don't give enough info, please ask or look up my other question titled "grounding issues"). Last week i was out in the bronco, after several starts and stops I tried to start to make a 5 minute drive home. Truck was dead(like battery). I was fortunate enough to receive a jump start attempt, only it kept making the dead battery sound. He finally, after about 20 minutes of trying, he had to leave. I played around with the cables, checked as many grounds as i could, and even put the jumper cables off my own battery to chassis ground and starter solenoid, to check it. Engine attempted to start, so i pulled cables so I didn't damage anything. Then, one more try to start=successful start. Drove home and it wouldn't re-start. I tried to jump it today off my other car=one slow turn followed by a bunch of clicks and then nothing. So, to rule out battery, i disconnected truck's battery cables and tried to jump start off of car(using jumpers straight to cables)= nothing at all( not even a slow turn). Then, to rule out solenoid, i used a screwdriver to jump across solenoid=i did a few slow turns but then nothing, this time dome light also died and i had no lights anywhere, so i checked all the 50 amp fuses(all good, I don't have my haynes manual with me right now). So, out of time, i put the cables back on battery, and put up what few tools i have here at my apartment, and put jumpers back in the bronco, i noticed dome light was on, so just for kicks i tried to start once more=perfect start. It proceeded to start perfectly 4 more times, with no issues. So,i have a very inconsistent starting problem. Starter has been tested twice. I don't know what to check next. Please help, i need my truck to run, so i can do some work on my civic

 

You have resistance issues. Disconnect both battery cables again. Disconnect the positive from the solenoid as well and take a resistance reading on the chunk of cable between it and the battery and again on the one between the solenoid and the starter making certain it is not connected or touching either device when you do. The resistance on any piece of cable that size should be under 4 ohms and ideally close to ZERO ohms. If positive cable checks out, repeat the process for the negative cable making certain it is not connected to the battery or the truck when you do. If both cables check out, do the same resistance reading across the big terminals of the solenoid with the solenoid engaged but no big cables attached to it. This measures the amount of resistance across the start terminals of the solenoid. Again, this reading should be very very low if not zero. Any cable or solenoid with high resistance is your culprit and should be replaced.

 

Thanks greystreak! I hadn't thought about an internal resistance. I was too convinced on grounds. One quick question, you said, to check resistance across thee solenoids while, engaged, wouldn't I need the wires to be hooked up and power going into the solenoid to engage it? & wouldn't that make a resistance check useless on it?

 

You only need the small wires connected, they make the solenoid close the internal contacts between the big terminals. The big terminals are what carry the current from the battery to the starter.

 

What CS79bronco said! Exactly. I've actually seen a solenoid have part of the internal mechanism crack causing a no-start condition even though the solenoid still actuated. THe piece that closes the contacts between the big terminals had separated and would intermittently energize the terminals when you hit the key.