top clearance lights out. markers and headlights ok

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rustyrobins
Posts: 11
Joined: Tue Oct 19, 2021 9:27 am
Location: Puget Sound

top clearance lights out. markers and headlights ok

Post by rustyrobins »

Hi, getting ready for an outing this weekend I discovered all my top clearance lights are not working. The headlights, bottom marker lights, blinkers, and brake lights are all working. Top clearance lights don't work with the key on either. I have an ICC momentary switch on left panel. I have searched this forum for a clue to fix, no luck yet. Often a ground issue is to blame for something like this. Is it possible that a bad ICC switch would cause this? I have done some crawling around under the dash to string the scangauge wire, maybe I bumped something. If anyone has fixed this same issue please reply. It may save me a bunch of time. Thank you ahead of time. AND BTW, when we find the answer to our fix issues please post your results and method. This include me. Thank you
Rusty & Catherine
1996 Safari 3740 Ivory Edition 3126 Cat
Safaritoonces
Posts: 200
Joined: Sat Nov 02, 2019 9:51 am
Location: Bowen Island, BC
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Re: top clearance lights out. markers and headlights ok

Post by Safaritoonces »

The clearance lights are daisy chained and are powered through the headlight switch on the instrument panel on my 2000. The wires are marked as clearance lights but I think SMC only started printing on wires shortly before 2000. The clearance light wires on mine run down the drivers pillar and then are connected to the dash headlight switch. I did some projects on my electrical changes on the dash wiring that may be of some help but it was a couple of years ago. The projects are on this site or you can look under the menu on the following link
https://safaritoonces.org
Robert and Bev Lewis
2000 Safari Continental, since 2017
3126B Cat, 330hp
MD3060 Allison
Bowen Island, BC

https://safaritoonces.org/
stuplich@ymail.com
Posts: 1113
Joined: Mon Oct 28, 2019 8:51 am

Re: top clearance lights out. markers and headlights ok

Post by stuplich@ymail.com »

Rusty & Catherine
Using a JUMPER WIRE, an OHM METER and this WIRING DIAGRAM: http://jexler.s3-website-us-east-1.amaz ... lClear.pdf (From Jim Exler, in the Safarifriends Legacy Content), I was able to diagnose and repair a similar clearance light problem.
BTW mine was a disconnected/loose wire on the 10 screw 'terminal strip' located on the front firewall, in the front run bay, below the driver's side windshield ... ("TS" on the drawing).
Mel
'96 Sahara 3530, mine since '01
250 hp 3126 Cat, MD3060 Allison
TDJohn
Posts: 313
Joined: Sun Oct 27, 2019 11:34 pm

Re: top clearance lights out. markers and headlights ok

Post by TDJohn »

If I recall correctly, when the ICC switch is activated it breaks the ground, turning the clearance lights off. If temporarily bypassing the switch would be an easy way to know if the ICC is the issue. If the lights still don't work after bypassing the ICC switch, then the problem is elsewhere.
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
rustyrobins
Posts: 11
Joined: Tue Oct 19, 2021 9:27 am
Location: Puget Sound

Re: top clearance lights out. markers and headlights ok

Post by rustyrobins »

Thanks John and thanks Mel! It was an ICC switch issue. The switch is ok but one of the spade connecters had come off. So I now have my clearance lights and my ICC switch works. I think I will start using it. I never had a ICC switch before I would just turn my lights on and off. I really appreciate big rigs and cars that signal me when it's ok for me to get in lane. Thanks again John. And thank you Mel, that diagram is really useful and it did help me do the fix. Study of origin of ICC is an interesting read. Makes me think of a line in the Dave Dudley song "6 day on the road" that says "the ICC is a checkin' on down the line"
Rusty
Rusty & Catherine
1996 Safari 3740 Ivory Edition 3126 Cat
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