I have an 87 Ram I6 M4. I thought I was having battery or alternator issues, when the truck was running I was loosing power and had to turn my lights off to keep the truck from stalling. The next day I boosted it and it ran until I took the cables off.

So today, to see if it's the alt, I threw a fully charged optima and it wouldn't even let the starter engage. I have LOTS of juice. Also, just thinking on a fluke the battery was messed up I put a booster back on it and nothing ....

Ideas ?

 

Check all battery connections power and grounds,even the engine to body,battery to body ground.
If you have little electrical power with engine running it could be the alternator.

 

All the grounds and conenctions are good.

I know it's most likely the alternator, but the problem is it won't start in the first palce now. ANd the truck could run off that optima with no battery for an hour plus for sure.

The starter doesn't even click or anything.

 

check to see if the starter is getting power at the soliniod when you turn the key(I know easier said than done).
Carefully use a screwdriver and jump the connection at the starter to see if the starter is good.

 

Check the positive battery cable and connections very closely. They can corrode internally and fail, and will cause your symptons.

 

Have you checked the hot lead on the starter for dirt/corrosion/tight fit? Look for shorts to ground and or poor grounding with a multi meeter. I doubt it's a fusable link or charging system malfunction, as you put a new bat in with a full charge and had ano start condition.

 

Okay I've done that and the starter works fine

So it's what ???

PS. Thanks for all the help guys ! I'm a dummy at these things... I'm used to computer controlled ignition and what not !

Update !

Okay, so I grab some warm oil from in the house and change the oil and filter (Needed to be done anyway, and figure the warm oil will help her start better) put the key on and jump the starter, and she fires right up ! I let her warm up for about 10-15 mins... and then try to start it again, but with the key.

Starts right up ....

So wtf ! I don't understand, could it have just been a loose connection or something ? Shut it off and started it about 5 times, started no problem each time !

The truck had sat for about 4 months prior to this, could it have been something because it had been sitting or ?

 

clean and coat with dialectric grease all electrical connections in the battery/starter system.

 

I agree with born, if it's now suddenly starting with out any adjustments, somethings loose. I had a problem with my Saturn similar to this, where there was a loose connection and until I found it, it was a crapshoot whether I would have electricity or not. When it was warm, the metals expanded and the car would fire up instantly, when it was cold, the metals shrank and caused loose connection and no juice. I guess if you live in a climate that sees both very hot summers and cold winters, you should check every once in a while to be sure everything is still tight because of the varying tempurature extremes.

 

Yup I'm a Canuck just like you

Well I geuss I'll check all the connections at work tomorrow and tighten everything down. Maybe upgrade all the grounds and make a little Alt re-wire while I'm at it !