Ok, so I've been reading this forum avidly ever since I acquired my 1990 22RE pickup a couple of months ago. Usually by searching past threads I've been able to find pretty much everything I needed to know, but the time has come to ask a question.

I'll start with a long winded description of the specifics of my problem - my questions are at the end.

I started having starting issues a couple weeks back. The dreaded click. Since I couldn't make it reproduce reliably (it always happened at the worst times, of course) and I lacked a voltmeter (at the time) I decided to go for broke and replace the starter contacts (thanks 4Crawler!) without checking any of the electricals upstream. That seemed to fix the problem for a couple of weeks.

Yesterday, I stopped for gas. Attempting to restart the truck, I heard to starter relay clicking repeatedly for several seconds. Finally the starter turned weakly, the engine caught and I drove 120 miles home (at night w/lights, stereo, the works) without any more problems.

Today, same situation starting in the morning. In the afternoon, I couldn't get it to start period. Luckily, a friend was nearby, and we jumped my truck. Started right up, no clicking. I drove 20 mins home, again no issues. Turned off the truck at home, and immediately tried to restart it. Nothing but a few clicks.

Took the battery in to get it checked - the battery is fine. The nice people at the auto shop even charged it for me. Now my truck starts great, every time.

My diagnosis:

I'm pretty new to electricals, but it sure seems obvious that the battery isn't getting charged, which would point to the alternator. However, I read in a past thread that if the alternator wasn't doing its job, disconnecting the negative terminal of the battery while the truck was running would kill the engine, which it doesn't. Also, my crappy analog voltmeter shows 14v, steady, at the battery terminals with the truck running, which seems right.

My questions:
From my understanding of the charging system, it seems like if the alternator had failed, I wouldn't be able to drive 120 miles without having some serious issues. As it is, once the engine is running everything is fine - no rough running, no idiot lights, nothing.
-What else could be causing the battery not to charge?
-I've read that corroded ground straps can cause all sorts of issues, but how does one check for corrosion, short of cutting the ground strap open?
-Is there anyway of testing the alternator reliably while it's on the vehicle with just a crappy analog voltmeter? The FSM shows a complex setup with an Ammeter and a voltmeter. I just have an analog voltmeter and as far as I can tell it's precision is at best +/- 1 volt.
-How do I know if I have an internally or externally regulated alternator?
-Is there something else that I'm missing here???

Any insights/tips/solutions on troubleshooting alternator and starting issues would be greatly appreciated!

Thanks,

Matt

Have you had the battery check for a short or anything; parts store can do a load test for you;

Also check the alt brushes; how-to is in the maintenance section here.

No brake/charge light flagging I take it.

You probably have already checked this, especially since it sounds like you already took out the battery. But have you checked to make sure that your battery connections don't need to be cleaned? The very first thing I do on any charging/battery problem is clean the terminals. Use hot water and baking soda. If you are in a parking lot somewhere, coca-cola from the nearby vending machine works too (that is why I don't drink that stuff). Make sure you use a wire brush (wear safety glasses) and clean botht the battery terminals and the cable connections themselves. There may be more to your problem, however it sounds like dirty connections to me and it is a good place to start. Dirty connections will do exactly what you are describing. It will start fine one minute and barely crank the next.

Good luck

Cool, thanks for the tips.

Yeah, I cleaned the hell out of the terminals and replaced one of the battery cable ends 'cause it was pretty corroded. On the way home from work I stopped at an auto electric shop and they tested the charging system and said the alternator seems to be outputting fine. Hopefully just dirty connections then! I'll just have to wait and see I guess.

--Matt

my truck was doing the EXACT same thing. changed the terminals and n problems since.

You may want to just change the battery cables completely, if your end terminal was corroded there may even be corrosion down inside the cable that you can't see causing poor current flow. Check the alt. to battery cable too, maybe one end or the other is almost broken right inside the sheathing or torn away from it's connector pin/ring but you can't really see it. I have sometimes found electrical problems to be an almost severed wire or connection that looks fine at a glance.

Did you drain your battery by accident some time before this problem happened? Even months ago? Reason being once your battery is drained it usually needs to be charged with a charger for a long period, not short drives (an hour or two is a short drive) because the alternator doesn't provide enough current for long enough to charge the battery deeply again so effectively your cold cranking amps are very low and if the temp goes down or your truck just sits for a while that superficial charge will not be enough to start up again. The parts store quick charge probably helped juice it up, but if you can, put it on a low amp long charge over night. Disconnect your neg. cable if you do this. Worst case, your battery is not taking a deep charge any more. Parts store gave it a fast charge with a lot of current which is a bandaid but if the problem happens again consider a new battery. Now would be a good time to check the water level in your battery if you have one that requires/permits filling. There will be a max and min fill mark on the side of the battery like on a fluid reservoir. Use distilled water only to bring it back up to max. If you have a no maintenance battery, do not try and remove the cell caps.

F