Do I have have a Bad Alt?

Malsteem · 09-23-2009, 04:21 PM

A month a go I replaced my starter, because ti had gone bad.
Last week, when my wife was driving to pick up my daughter from school, the Zuki stopped running and we had to have it towed to our house. After about 2 hours it turned over again, and I stopped it.

Two days later I drove a friends house and it almost stopped running. I could get it to go 5 mph. We charged the battery on his charger for 3 hours and drove it home w/o problem.

Another yard mechanic tool me to check the alt by taking off the + cable instead of the - cable. We took off the + the Zuki started to sputter, but then it came back to life w/o any problems. Today the Zuki would not start after my wife drove it for abotu 8 miles. We took it to Les Swaub and they said the battery is dead (we bought it 2 days ago).

What do I need to do to fix this thing?

cmays03 · 09-23-2009, 05:39 PM

well what you can do is get a volt meter and start it up and put the meter to the battery and see if your getting 14 volts or more. if you are then the alt is working if its less than 14 volts then its not charging the battery. what the alt could be doing is charging at times or very little. so when you took the cable of the battery it could have been charging enough for it to stay running. also you could take the alt off and take it to any auto parts store and they should be able to check it for your for free.

aquanaut20 · 09-23-2009, 07:45 PM

The thing you should not do is remove the battery cables while the engine is running. The battery acts as a load and assists in regulating the voltage and amperage. An unregulated power source can be deadly for any elecronics in the vehicle, ECU ring a bell?

Running an alternator open and then applying load may produce sparks/spikes and blow the regulator or diode bridge not to mention posibility of battery exploson.

Maybe your friend will help with the repair bills when you folow his advice......

Malsteem · 09-24-2009, 10:12 AM

Took it to a shop. The alt is dying.

So know to look for a new one.. how many amps do I need?

cmays03 · 09-24-2009, 10:35 AM

i think they only make a 55 amp. i'm sure you can get yours rebuilt and ask the rebuild shop if they can get more amps out of it but i bet it would be pricey.

aquanaut20 · 09-24-2009, 12:10 PM

There are direct replacement alternators available, reman, 75amp, warranty.

Race Pages - Suzuki Alternator - 1997 Suzuki Sidekick Alternator

Suggest you check around.

Richard Craneum · 09-24-2009, 12:20 PM

Take the Alternator off and go to Auto Zone. They have a tester for it.

Give them a call and ask them, sometimes they do not have the adapter and they can test it with another machine with the alternator installed in the engine.

kick-fix · 09-24-2009, 12:31 PM

never listen any yard mechanic, (that is why he is there and not in a real shop)
sorry.
gee, this warning is in every ASE book ever published.
Never run the ALT (regulator inside , right?) or run the risk of regulator going nuts and blowing the ECU and radio and other electronics to kingdome come.

as other poster said, check the voltage across the battery running.
14.5v running.
if it reads 12.4 then ALT is dead (check belt)
or you have corrosion on the FEED.

I have 2 pages, one for power feed and one for ground feed.
about 1/2 all fails or more on this form are (non starter , non alternator related)

that is , bad wiring.
common-failures

power;
Electrical power failure

bad battery cables. (inernal corrosion, my no crank page shows how to test it)
battery ground cable on tight on the top starter bolt ( did you put it back correctly)
fuse bad in fuse block. RF fender
bottom of RF fender fuse block

top 3 fails.

most ppl come here when they just replaced the battery and sometimes, battery, alternator and starter.

Malsteem · 09-24-2009, 01:18 PM

When we checked the voltage it averaged around 11.73.

The batery and starter are new, but i will go and check the connections. When we changed the starter we cleaned the connectorts and we replaced the corrodied ends (that attach to the battery post) with new ones.

kick-fix · 09-24-2009, 01:56 PM

check list (that num shows gross battery discharge)
1: alternator body must be clean agains its brackets, and those brackets grounded to the block with clean interface (no piles of rust allowed)

2: the main power out lug on the alt , must pass to the fuse block 80a fuse and this in turn go to the battery + post view no corrosion. ( 2 points to corrode)

3: the battery cables good and terms , clean on both ends.

is your charge lamp on , at key on and goes out after starting? in I/P cluster?

no then replace lamp. if not on key on. first.

the IG-coil meter fuse must not be blown 15a, or the regulator in the alt will fail

if all the above is good, then ALT is bad

there are some batteries that are bad , and will cause the Alternator regulater to
go nuts. but I think , yours is ok. 11.7 is discharged.

when you charge it manually can you get battery up to 12.5v ?

that is my contribution to dead Alt.