Question about 1989 Isuzu Pickup 2WD

1 Answer

Blown fuse - What's it protect???

My '89 2.3 liter Isuzu pickup wouldn't idle and the alternator lite, brake warning lite and low fuel lite were on constantly while running. Drove it for days like this, battery never lost its charge. Found a blown fuse in the dash fuse panel. It was a 10 amp fuse, listed as Fuse #8 - Engine Back L.
Anyone know what this fuse protects? I can't find out what that means.

I don't know if this has anything to do with it, but a week or so ago, I had to install a push button on the dash to activate the starter solenoid. Banging on the starter had worked for a few weeks. Then that wouldn't help anymore. The solenoid wouldn't even click. Took starter solenoid apart, found nothing wrong. Added a ground wire from starter to frame just to eliminate possibility of a poor ground. That seemed to help only for a day or so. That's when I installed the push button. Worked fine like that. A week after adding the push button is when the current problem started. (the just now discovered blown fuse)
So I took the ignition switch apart, nothing wrong with that either.
Could all this be caused by one problem??? Engine Back L.???????
The truck has 390,000 miles on it. No rust on the truck, or evidence of wire corrosion. Help! Thanks!

Posted by on

  • Almost400000 May 31, 2009

    This fuse protects the slow cut solenoid and the back-up light circuit. My problem was caused by a wire from the reverse switch on the transmission.



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  • Isuzu Master
  • 20,706 Answers

In what country ?
My '89 2.3 liter Isuzu pickup
fuse are to prevent FIRES
ever see a wire burn red hot and then melt a fuel line (ugly *****)
fuses on cars with fuel are serious.!
lesson 2 is There are not 1 fuse for every load in a car, or you'd have 100s fuses.
lesson 3, the power distribution is a tree with branches fused.
same deal on cars, trains, boats and planes.
for the same reasons
my wild guess1
you work with no 89 2.3 liter schematic the proceed to hack it and find fuses blow. sure.

so my guess 2 is you bypassed the starter solenoid ?
and overload that circuit.!
the relay has purpose, its a current buffer (lesson4)
the reason car didnt crank
is the relay
the blk/white wire uses like 8amp
current is buffered by the relay to 30 times less.
This less current save you from burning up and expensive
ignition switch, (some are $100)
that 5 relay saves 100 bucks. and repeats.
the relay also us for logic
the USA laws mandate a park /in gear lock out
so the relay did that, at blk-pink wire.
now defeated. by you.
try a new relay (if hacking is a goal)
and put switch to ground (pin1,) and pin2 of switch to
brown -red wire on new relay. bam starter fixed
and no burn burned up ignition swithes or fuses.
see fuse 12 below. 10amps
that fuse can not run a solenoid direct, the relay must be working.
the starter solenoid uses a 60amp fuse. blk wire (main).

Blown fuse - What's it protect??? - 89-r2twsw33kdu1j1sbv1ad4ojf-3-0.jpg

Posted on Mar 02, 2017

  • Anonymous Mar 02, 2017

    all that to bypass a $5 start relay
    or bad transmission PRNLD switch
    or clutch switch>?? why?



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Posted on Jan 02, 2017

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Could be one of two things.

1. Your starter motor is no good.
2. If you turn on your lights and try to start the car and they dim to almost black, then you need to check the battery connections.

Posted on Jan 03, 2009

  • 15935 Answers

SOURCE: No power to ignition - ? please help! 91 amigo 2.3l

If everything is turning on, and there's power... check for 12V at the alternator. it may be out now.... or a connector came loose, or wire broke.

Posted on Jan 09, 2009

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SOURCE: Truck won't start.Has new

check the wires under the fuse box they might be lose

Posted on Aug 13, 2009

SOURCE: i have a 95 isuzu

Dear Sir,
Yes you are right it can wire problem for alternator, you can check , tow things to be check at alternator end , one is if battery light is showing on cluster that mean the small wire at alternator is ok, if not then light will not come on at cluster meter. and second wire is run from battery +ve terminal to alternator you can check voltage at alternator end if supply is there it means wire are ok if not may cause fo bad connection at battery end , it can also lead to no charging for battery. if both wire are ok you can go for alternator ,

Posted on Nov 01, 2010

  • 37 Answers

SOURCE: I have a 1996 Isuzu bighorn UBS69GW that has a starting issue the problem comes and goes and results in a clicking noise and an almost electrical buzzing sound if left for 20 min will start fine again


Posted on Feb 21, 2012

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