Isolation Module

[Transcender]

Hi, my new/old '98 JT is heading to the shop for inspection and I have a headlight issue that I'd like to fix before it gets there. The low beam does not work on the driver side sealed beam lamp. High beam works fine. I have no voltage at the lamp connector. I do have continuity from the plug back to the other end of the wiring harness. The harness runs back and plugs into a "Isolation Module". I haven't found any info on what this does. Could this be the problem? Can I bypass this isolation module? Thanks for any guidance and ideas on what else to look for.

 

[SteelHeadz]

Isolation module?, i'm not sure i've ever heard of that module on a TJ. Isolation module only exist on hybrid vehicles. Can you take a pic of it and post it?

 

[Crazy4diesels]

Do you have DRLs (daytime running lights) ? Jeeps with DRLs have a little control module on the firewall near the master cylinder. -John

 

[Transcender]

I just found out that the isolation module is typically used for for vehicles with plows (Fisher specificaly). It's some sort of relay box that tells the lighting system if the plow is in use and turns the regular headlights off and turns the plow lights on. I will now do a bit of research on how to remove this and revert back to the stock lighting wiring. Fortunately, the previous owner only used the Jeep a few times for plowing before he bought a truck w/plow.