Last post on Oct 14, 2012 at 5:22 AM
You are in the Isuzu Trooper
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Isuzu Trooper, Isuzu Trooper II, SUV
#33 of 42 86 trooper charge problem
Mar 30, 2009 (1:14 pm)
I have an 86 trooper I just bought yesterday. brake and alternator warning lights are on intermittantly when running. When they are on, my tester says the alternator is only putting out 11 volts. When/if they go off, my tester says it is putting out 14 volts. Supposedly the alternator was JUST rebuilt (days ago). Is tthis simply an alternator problem or could it be something else in the system? how can I track it down?
#34 of 42 Re: 86 trooper charge problem [izzbo1]
Mar 31, 2009 (4:08 am)
It sounds like a bad alternator to me. Even fresh out of the box, some alts are not right. There are diodes in the alt that can be bad and the alt will still test as OK. Getting a quality rebuild on the alt is generally necessary.....cheap ones don't seem to hold up or work at all in many cases.
Your year has two style of alt....one with IC regulator built in.....one outside. If your voltage regulator is outside, that is likely the cause.....otherwise, you seem to need to replace the alt. Make sure though, that the ring terminal on alt is not close to or grounding on alt case. Very commom problem when installing and tightening terminal nut. If it is OK, then above would apply.
Part nos. at www.myisuzuparts.com HTH One guys opinion
Mar 28, 2011 (5:42 pm)
hi i have a 98 trooper 6cyl im haveing an issue with voltage spikes ,it spikes at 18 and above it blew the highbeams and put the tranny in limp mode . if i put the vehicle in park and turn off and on again its fine but will spike again it fluxuates alot and sometimes stays at 18v but will eventually drop and fluxuate more . i have put many new grounds all over the vehicle but hasnt helped ive cleaned all the plug connections i could find by tranny and engine . next is to replace the alt. but ive been told by many people that the alt regulator wont fluxuate like that its either good or bad no in between . if any one can help i would really appreciate it thank you, jason
#36 of 42 Re: voltage problem [jostrander]
Mar 29, 2011 (2:34 am)
Most certainly a failing internal regulator will exhibit the behavior you are experiencing. It may be intermittent due to the different loads it is seeing, but should NEVER be above 13.6 (14) volts...if it is, the regulator/alt is bad.
The only exception to this would be if you removed the battery and the alt was running the systems, in which case the regulator would spike all over the place as loads changed and it had no baseline 12 Volt signal from the battery. Never disconnect a battery from a running ECM controlled vehicle of any brand. It can have disastrous results.
HTH One guys opinion.
#37 of 42 Re: voltage problem [atfdmike]
May 04, 2011 (8:01 pm)
I'm experiencing pretty much what ostrander was with the voltage spiking to 16 but I also have the dash light all blinking on and off while it's spiking (I can here clicking as they do under the dash above my left knee) then it will return to normal but when I come to a stop the tranny starts like it's in third gear (very slow. it's an automatic) If I turn off the car and restart it, it drives normal for a while then will eventually Start all over again. Does this sound like the alt?? or Regulator??
Anyone else Having this problem besides me and ostrander.
#38 of 42 Re: voltage problem [trooper97]
May 05, 2011 (2:24 am)
Based on the symptoms you describe, and knowing that Isuzu's are very voltage sensitive, you really need to check your connections and vehicle grounds to make sure they are good. If they are and the intermittent problems keep happening, then you may have a harness that has a broken conductor/wire or the problem is the alternator/regulator. You don't say what year and model you own, but if a 97 Trooper, then the regulator is internal to the alternator, and you may wish to get a new one. Use caution in buying one as the unique construction of the alternator and quality must be good to insure the voltage and circuits work properly. There are many horror stories about new alternator problems or failures (I am one of those that experienced it) due to bad rebuilt quality or parts.
HTH One guys opinion
#39 of 42 Re: voltage problem [atfdmike]
May 05, 2011 (8:50 am)
Thank's atfdmike, I think this will help. I'm taking it in today and will leave it with the shop for a couple of days to see if they can determine the cause. I'll let you know what I find.
By the way it is a 97 3.2L Sorry about that.
#40 of 42 Re: voltage problem [trooper97]
May 22, 2011 (10:08 am)
Ok I've had the Trooper back for a couple of weeks and everything is running great! So the alternator was the problem.
Thanks for your quick response and help atfdmike.
#41 of 42 Re: voltage problem [trooper97]
May 22, 2011 (3:38 pm)
Great news! Thanks for posting your results, as it helps others down the road too!
#42 of 42 96 Alternator issues
Oct 14, 2012 (5:22 am)
My 96 Trooper Se will not hold a charge. Mechanic replaced the alternator 3 times and none held a charge. This vehicle has been going through alternators every year and now none are working. Please help!!! It will indicate it is charged and shortly the battery is totally drained.