Need Help! Engine won't start warm!

[gt1009]

Ok, so today I started my truck up for a quick trip to super target. Started fine in the 35 degree weather. But when I tried to start it for the return trip, it wouldn't start. I got a jump and it started right up. The werid thing is that when I got home, I turned it off then tried to start it right back up, and it wouldn't go. I think that the problem lies in my alternator, because i've been driving it for a while with no problems, but with my headlights on the sarter won't start the next time. It seems like the batteries aren't getting any charge from the motor, and the only time they get charged up is when they are jumped. PLEASE HELP ME Oh, and one more thing, the voltage guage on my dash doesn't display anything. The needle just sits all the way to the left.

 

[85-m1028]

First thought was how did you get a jump from someone with a 24v system??

If your needle doesn't move then your probably not getting a charge.. check the bulbs in the gen1 and gen2 dash bezzle I think if they burn out the charge system doesn't work? Get a volt meter and see if the alts are putting out any voltage...

 

[CCATLETT1984]

he would be able to get a jump, cause the issue lies with the front battery. (he said with lights on, that is drawn from the front battery.) odds are that the alternator has given up. If a diode were to fail in the alternator, then the voltage could drop and not cause the gen light to come on.

 

[ken]

Try taking some cold water and pour it onto the injection pump. If it starts then the ring is bad and you'll need to have it rebuilt. DB2 pumps are famous for this.

 

[gt1009]

Thanks for the help,

First thought was how did you get a jump from someone with a 24v system??

well, to do this i just hooked it up to the other car's battery, then hooked the cables to the terminals on my front battery. Another note, it didn't start up today again. I'm going to test the alternator soon and I will post what happens to help any others who might end up with the same problem.

 

[mangus580]

I agree... if it starts when you do that, your drivers side alternator has failed...

 

[gt1009]

Okay guys, here's one more piece to add to the puzzle. The guy who owned this truck before me had converted it to a 12 volt starting system, so i don't know if that changes anything. It's dark here, but i'll go check tomorrow and see if it has one or both alternators still attatched.

 

[CCATLETT1984]

yeah it does, that means that your starter is now 12volt instead of the orignal 24volt. the original alternators are ran in series, when the conversion is done either only one alternator is retained or two seperate 12volt charging systems are created. the later is used mainly when you have something with a large load being used that you dont want to affect the battery that you start the truck with, like a winch or radio equipment.

Dp you have ONE or TWO batteries?

ONE or TWO alternators?

ask the guy that you got it from how he had it wired, you now have a system that has been changed from factory and is going to be hard to troubleshoot without knowing how its setup.

 

[CUCVFAN]

Just a point of clarification that ida34 helped set me straight on: The alternators are not really run "in series". The charging system is 2 separate charging systems, each charging 14V (hence the ground isolation of the alternators) to their respective battery.

There are several options for 12V conversion, so you need to be sure how it was set up. Start the truck and put a voltmeter across the terminals of each battery. You should get 14.4V (plus or minus).

 

[85-m1028]

and the 24v needle gauge will not work when converted to 12v...

 

[CCATLETT1984]

I was trying for simplicities sake, he doesn't have the stock system anymore so the "details" about its charging system are a mute point in diagnosing his issues. the charging system can be hard to wrap your head around, he doesnt need to in order it solve his issue so I was leaving it out.

 

[CUCVFAN]

I was trying for simplicities sake, he doesn't have the stock system anymore so the "details" about its charging system are a mute point in diagnosing his issues. the charging system can be hard to wrap your head around, he doesnt need to in order it solve his issue so I was leaving it out.

I understand the "details" are not necessarily related to his problem, but leaving out the details is not the same as providing the wrong information. My point is that people could be reading the thread who might have a charging system problem now or at some point in the future and they will be confused by the incorrect information, regardless of the intent to simplify.

 

[gt1009]

Okay, well i went out last night, there was only one alternator. After I started it up and checked the voltage I was only getting 8 to 10 volts across the batteries. The new alternator comes today and hopefully it will be back on the road tonight. Thanks for all the help

 

[gt1009]

One final note... If you need an alternator, it has to be ordered from syracuse, NY. So, if you think yours is going bad, test it or get one ordered soon! It was also about twice the price of the one that was listed for the 84 blazer, because it is an industrial alternator, made by the same guys that make them for semis.

 

[jumpmasterjim]

Couldn't you just rebuild the one you have. I priced an alternator last night and almost had a cow. I'm gonna try to get rebuild kits.

 

[mangus580]

Rebuilding is certainly possible. Locate a good rebuild shop, and you can probably get the parts from them.