Charging system service

[fuzzydog]

my truck is a 1991 F250 7.3 5 spd with no mods.

Yesterday evening after a short trip to the grocery store my batt light came on for a few seconds and went out. This morning, after starting the truck (started right away as per normal) I put a VOM on the batt and got 12.82 V and slowly increasing. This was at high idle. No batt light on the dash though.
Headed off to work, fan blower on high, lights off, stereo off and the batt light comes on. turned the blower off, batt light stayed on but when I got onto the highway and got some revs going, the batt light came off and the gauge needle visibly jumped from N to R. Between shifts it would drop back to N then jump back up as I revd. Somewhere in there the batt light went off. So, seems like the blower drew down the batts while the truck was idling, but the charging kicked in and topped the batts back up as revs increased.

I'm pretty mechanically competent and this sure seems to me like weak/worn brushes. Are the brushes in these alts easily replaceable? This truck is my daily driver so can't have too much down time.

oh yeah, one more question - are these trucks internally or externally regulated?

 

[DragRag]

Your alternator is dying a slow death, install another before it leaves you on the road.

 

[typ4]

91 is external, I have a 100 amp unit off of a motorhome I would make you a heck of a deal on, I can freshen it up or as is, it worked fine 26k miles on the MH If you have a pic of yours I can also send along brushes for yours, it should be a 1G large case.

 

[fuzzydog]

typ4, thanks for the info and the offer, but with the border and all - it will just be easier for me to get some brushes at the FLAPS.

Btw, the 2nd part of my sig would look like this:

90 Cherokee 300K+ on the clock (not the daughter's rig though. 35" tires, 6.5" long arm suspension, explorer 8.8 rear diff, waggy dana 44 up front)

 

[typ4]

would customs be that harsh on a used part?
Them cherokees run forever.

 

[fuzzydog]

Its not so much the duty/taxes/customs, just the shipping time. I've got to get this done today, after work. Now, if you had a 160 amp alt available.......... I'm pretty sure that the 2 huge bosch driving lights I put on my truck last fall have accelerated the demise of my current alt brushes.

Weather up here was just gorgeous this weekend, and almost all the snow is gone. I haven't started the cherokee since the fall and she fired right up on Sunday. Starting to get a bit of maintenance done for the coming wheeling season.

 

[jwalterus]

I recommend swapping over tho the summit racing alternators, I run em in most of my cars, internally regulated, color of your choice, about $100, 100 amp I believe for most of them

I have one that's been in my mustang since '97, no problems with it

 

[typ4]

Its not so much the duty/taxes/customs, just the shipping time. I've got to get this done today, after work. Now, if you had a 160 amp alt available.......... I'm pretty sure that the 2 huge bosch driving lights I put on my truck last fall have accelerated the demise of my current alt brushes.

Weather up here was just gorgeous this weekend, and almost all the snow is gone. I haven't started the cherokee since the fall and she fired right up on Sunday. Starting to get a bit of maintenance done for the coming wheeling season.

Like these Hella's?

I like the 3G alternator upgrade, taurus and some aerostar vans. 130 amp, most test about 150. Very easy swap.

 

[THECACKLER]

X2 on the G3. Mine came off of a 91 Lincoln... but the Taurus and Windstar's with 3.8's have them. My regulator went bad, $40 for a new one @ AZ... I got the G3 used for $35...