83 pup headlight issue

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lost
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Isuzu vehicle(s): 1983 P'up LS, long bed, 5-speed, gas

83 pup headlight issue

Postby lost » Wed Jan 21, 2015 3:51 pm

Hey guys. Last night I turned my headlights on and they worked for about thirty seconds before both shutting off. All of my marker/blinkers work but neither the high/low beams work. Any suggestions would be great. Thank you.

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puttputtinpup
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Re: 83 pup headlight issue

Postby puttputtinpup » Wed Jan 21, 2015 6:01 pm

Have you checked all the fuses?

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Paul
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Re: 83 pup headlight issue

Postby Paul » Thu Jan 22, 2015 1:26 am

There are no fuses in the headlight circuit. There is a fusible link in the battery feed but other circuits would be dead if the link were open.

There is, however, a circuit breaker serving only the headlight circuit which is located (inexplicably) under the dash on the left side, just above the QOS box, taped to the big harness (or sometimes just hanging down from the harness). I have had my headlights go out and found this circuit breaker and it had a bad connection on one of its terminals. I soldered both of the terminals and it has been OK for a long time now.

The circuit breaker is a small tin box (about 1/2 x 1/2 x 1 inch) with two wires or terminals.

Paul
'84 P'UP 2 wd diesel, 5 spd with 0.78 fifth gear and differential back to 3.73.

jasonw86
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Re: 83 pup headlight issue

Postby jasonw86 » Thu Jan 22, 2015 5:47 am

Paul wrote:The circuit breaker is a small tin box (about 1/2 x 1/2 x 1 inch) with two wires or terminals.

Paul


And, one of the wires is red, the other black. Both about 12 gauge in size.

The main switch could also be the problem.
1984 diesel LS long bed 4x4
1983 diesel 4x2 long bed
1984 diesel 4x2 short bed MPG Plus
1984 diesel 4x2 automatic longbed
1982 diesel 4x4 LUV mikado shortbed
1986 gas LS 4x4 Trooper II 2 door
1984 turbodiesel 4x2 automatic longbed

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JoeIsuzu
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Re: 83 pup headlight issue

Postby JoeIsuzu » Thu Jan 22, 2015 9:00 am

Or possibly the dimmer switch.

Jack

jasonw86
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Re: 83 pup headlight issue

Postby jasonw86 » Thu Jan 22, 2015 4:11 pm

JoeIsuzu wrote:Or possibly the dimmer switch.

Jack


When I first read this I was scratching my head. You meant to say the high/low beam switch contained on the turn signal assembly. The dimmer switch controls the intensity of the instrumentation illumination.
1984 diesel LS long bed 4x4
1983 diesel 4x2 long bed
1984 diesel 4x2 short bed MPG Plus
1984 diesel 4x2 automatic longbed
1982 diesel 4x4 LUV mikado shortbed
1986 gas LS 4x4 Trooper II 2 door
1984 turbodiesel 4x2 automatic longbed

Pupfocused
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Re: 83 pup headlight issue

Postby Pupfocused » Thu Jan 22, 2015 6:24 pm

Try pulling back on the turn signal switch, if the lights come on and stay on when the turn signal is held back then the light switch is bad.
Jim
1981 diesel pup(gone)
1985 4x4 diesel pup
1986 diesel trooper.

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JoeIsuzu
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Isuzu vehicle(s): Original owner, '83 LS Diesel, 5-spd, 2wd, Long Bed, restoration in progress!

Re: 83 pup headlight issue

Postby JoeIsuzu » Thu Jan 22, 2015 7:59 pm

jasonw86 wrote:
JoeIsuzu wrote:Or possibly the dimmer switch.

Jack


When I first read this I was scratching my head. You meant to say the high/low beam switch contained on the turn signal assembly. The dimmer switch controls the intensity of the instrumentation illumination.

No I meant to say the "dimmer switch". ;) At least where I grew up, that's what it the high/low beam switch was called (but it was on the floorboad back then). :) But yes, that switch.

Jack

jasonw86
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Re: 83 pup headlight issue

Postby jasonw86 » Thu Jan 22, 2015 8:09 pm

No worries. I got a laugh out of the fact that it took so many seasoned p'upsters to provide a complete answer.
1984 diesel LS long bed 4x4
1983 diesel 4x2 long bed
1984 diesel 4x2 short bed MPG Plus
1984 diesel 4x2 automatic longbed
1982 diesel 4x4 LUV mikado shortbed
1986 gas LS 4x4 Trooper II 2 door
1984 turbodiesel 4x2 automatic longbed

1982diesel
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Isuzu vehicle(s): 1982 Chevy Luv 2wd Mikado Shortbed diesel & 1982 VW Vanagon 1.6l factory diesel (currently being rebiult)

Re: 83 pup headlight issue

Postby 1982diesel » Mon Jun 27, 2016 1:12 am

Hi All

I was having this exact problem too:

With the truck running or off, I had all my lights working, EXCLUDING headlights.
Oddly enough as noted earlier in this post, when I pulled back on the turn signal switch my highbeams would come on.
So I new the head lights worked. Since their is NO Fuse for the headlights I was kinda stumped, until this post!
I first pulled the switch. It was very easy to remove the black knob, lockring, and fish it out from the dash.
I found that it had dropped a wire. The switch had so much dust on it that I was surprised the dimmer worked at all.
I took a stiff paintbrush to it to removed the dust before soldered it back together.
Since their is no connector for this switch my previous heater core replacement work must have pulled a wire just enough to fail it...

And would you know what happened?

My headlights work again! Just in time for my 35 mile, 5AM morning commute!

I wish all my vintage car tinkering was this easy! I mean between reading, soldering, testing and typing this I've spend Zero $ and about 20 minutes! Thanks for the great blog post... The turn signal trick really helped to locate this problem quickly!

davidgrace
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Isuzu vehicle(s): 1986 P'up, 1986 Trooper II diesel engine project

Re: 83 pup headlight issue

Postby davidgrace » Mon Jun 29, 2020 12:40 am

Hmmmm

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shermtec
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Re: 83 pup headlight issue

Postby shermtec » Thu Jul 02, 2020 8:56 pm

A couple of years ago my 86 pup's headlights worked but the tail lights and side marker light would not come on. I ended up un-installing the light switch, cleaning it with electrical contact cleaner, then reinstalling the switch and everything was working again. Been working ever since.
1986 Isuzu Pup short bed 1.9l 4 speed manual gas