83 XJ750 Maxim Headlight and Instrument Panel Out

Was acting up a bit about 9 months ago. Finally got new tires but the headlight and instrument panel is dead.
Bulb is good. Fuses are good. Not getting any volts at headlight plug or on the dimmer switch. Turn signals, back and brake light work fine. If the dimmer switch is bad I can see it would mess with the headlight I guess. But why the instrument panel? Not sure how to get to the bottom of this. Just need a little direction on isolating the problem or my next move. Thanks.

 

Are you running with the original fuse box? The fuse clips get brittle with age and crack, causing intermittent (or permanent) open circuits.

 

Yes original fuse box. How would I check to see if that is the cause? Its dirty but the clips don't appear to be cracked.

 

You have to look very closely, with the fuses removed. You can also test for continuity at the crimp of each pair of wires. A continuity test should be performed with glass fuses anyway, since they often pop, or break, near the end cap where you can't see the failure.

The other easy thing to check is the connectors behind the headlight (insde the bucket). Make sure they are all clean and making good contact.

 

Will do it tomorrow and let ya know if I find anything. Thanks k-moe.

 

You should really upgrade to blade type fuses block. The block I bought was like 12$ off of Amazon .

 

^ that, or get new fuse clips and rebuild the box. Both are cheap insurance.

 

Yea the fuse block looks pretty simple to work with. Speaking of I checked the continuity of the fuses and crimped wires and they all passed.
The wires in the lamp bucket looked ok. Pulled them apart and reseated them. But no go so far on any response from the headlight or panel lights.

Started with removing instrument panel and checking stuff there. After this I was going to remove the tank and check the wires running underneath it. Any other suggestions would greatly be appreciated. The wiring stuff is new to me.

 

Think something likes this would fit? View attachment 21432

 

This was the problem. Read about it on a older post here. The start button switch contacts were very very dirty. Cleaned everything up and now the headlight and panel lights work!

 

Thanks for your help! Trying to find a right size blade fuse box to fit under the seat next.

 

Chacal sells one (well more than one really; it's not like we take turns passing one around).

 

Thanks k-moe, will check it out.