2nd Gen Non-Engine/Transmission Electrical problem

[MarkMiller]

My problem is that when my batteries are run way down and i fire the truck up the alternator puts out so much that it melted/burned the underhood fuse block. Not the whole thing but right were the supply line from the alternator runs into it the housing melted a little. It got hot enough to discolor the metal mounting tab of the 140amp main fuse on the side of the alt supply but it didn't blow the fuse. Not the side that runs top the battery. Its $1200 for a new block because it comes with all the wiring underhood. and would be a major PITS to install.



Anybody else had this problem?



I plan to "Y" the alternator line and run one finger direct to the battery. Opinions?

 

[MarkMiller]

No one has seen this?

 

[gathomas]

Mark, I'm no expert here, it sounds like you "might" have a diode problem in you alternator. I might be wrong but I think these Alts are producing 3 phase AC voltage, hence the need for three diodes. good luck

gathomas

westeren pennsylvania

 

[MarkMiller]

Thanks for the info. But what does it mean? I have a digital meter and can use it, but don't have any experience with diodes. What do I do from here?



Thanks

Mark

 

[gathomas]

Mark, I would seek the advice of a "qualified" automotive electrical repair shop. They are out there, you just have to find them... . (superpages.com) is a good place to start. If you locate a good one, some specialze in alternator and starter repair, they are a good source of education. Sometimes I've had good luck educating myself Via a Google search... . you just have to be persistent. I don't know if "Larry Bs" would be any help here or not, you've got nothing to lose by asking. By the way, is Broad Run near Manassas ? Good luck Glen

 

[MarkMiller]

I am about 10 minutes west of Manassas. I flat out refuse to take my rig to anyone to repair it. I have never found one that does anywhere near a reasonable job. I guess I will do some reading and fix it myself.



Thanks again

 

[DavidC]

On the diode section. You have to remove the wiring from the diodes and use an ohmmeter. You should read continuity in one direction only. If it reads both ways it is shorted, if no reading either way it is open. This is with the meter on the highest setting. Be sure to check the Batt. sensor under the Battery, should read between 9 and 11k. Also make sure all connections on the alt. system are tight.



Dave

 

[B.G. Smith]

Mark, you should check the batteries. If one or both of the batteries are going bad it can cause the alternator to really crank out the amps when first started, they all do it but the battery voltage comes back up quickly so it is only far a short period of time. It is important to let the engine idle for a while when first started if you know the batteries are low to prevent this type of melt down. Like jumping a vehicle with a dead battery and racing the engine on the engine on said car when it first starts, it kicks the alternator wide open and can daamage components. Best way to check the batteries if they are not sealed is with a hydrometer. Otherwise a volt mweter and load tester might be needed. bg

 

[MarkMiller]

Thanks for the tips. I whip out the multi meter this weekend and have my way with it.