Solved Problems with power/battery/alternator. 91 Explorer 4.0L.

[Justin Via]

Ok, so a few days ago I started noticing some mornings my battery seemed to be dead when trying to start, and was having to jumpstart.... bought a new battery... while installing the battery, the idiot at the garage hooked it up backwards!!! Which in turn fried my alternator (along with Lord knows what else). Replaced alternator, still has been draining the battery. I've tried a few different batteries, so I took the replacement alternator and had it tested... was told it was bad, bought another NEW alternator, put it on, and am still having the exact same issue... PLEASE HELP, AND THANKS.

 

[Mbrooks420]

The person at the garage would be paying to have this diagnosed/fixed if it were my vehicle.

 

[Justin Via]

Yeah, thanks... he has been paying... just can't find the problem...

 

[Roadrunner777]

Check or have him check for a blown fuse in the fusebox under the hood. Most cars don't fuse one of the leads to the alternator, so he may not be aware of it, but there is a fuse in the alternator circuit. It's one of the smaller ones, if memory serves.

 

[FR-425]

Start the engine, then disconnect one of the battery cables if the engine stays running the charging system is good.

If it stalls the charging system is bad.

Since you have a "new" alternator I would check the "fusible link".

The fusible link is a black box on the smaller of the two positive leads, near the power distribution block. A simple continuity check with a multi-meter. Don't test with the battery connected!

 

[BrooklynBay]

One simple way to find a parasitic current draw is to attach an Ammeter in series with the battery, then start pulling fuses until you see a large current drop. The PCM & radio have memory circuits which are always drawing a minimal amount of current.

 

[Justin Via]

One simple way to find a parasitic current draw is to attach an Ammeter in series with the battery, then start pulling fuses until you see a large current drop. The PCM & radio have memory circuits which are always drawing a minimal amount of current.

Thanks, and I did finally find, and remedy the problem... it was the fusible link, but it didn't look like the one you explained, which is what was throwing me off.... it now looks like the one you described because I removed the old fusible link (which was burned into) and replaced it with the 175 amp Mega Fuse that I purchased at the local parts store... I did however have to find some larger butt connectors, because the largest ones at the store were 8 guage, and the wire coming off the alternator was bigger.... 6 guage at least... thanks for the help, and glad to have learned something new.

 

[FR-425]

 

[BrooklynBay]

Thanks for the update. Your thread is now marked as solved.

 

[Justin Via]

Thanks for the update. Your thread is now marked as solved.

Thanks for the help!

 

[Perma Fried]

Thanks, and I did finally find, and remedy the problem... it was the fusible link, but it didn't look like the one you explained, which is what was throwing me off.... it now looks like the one you described because I removed the old fusible link (which was burned into) and replaced it with the 175 amp Mega Fuse that I purchased at the local parts store... I did however have to find some larger butt connectors, because the largest ones at the store were 8 guage, and the wire coming off the alternator was bigger.... 6 guage at least... thanks for the help, and glad to have learned something new.

How much did it cost for the mega fuse

Good job

 

[BKennedy]

The only time the OP was on here was when he posted this in 2018.