Gen 3 1999 Jimny blowing fuses, and engine light

Hello everybody out there!
I saved a year 1999 Jimny (The Wombat) from going to the scrapyard a few years back, and now finally after 5 years off the road, it is driving again. And driving well i must add!
98,9 % of rust removed, chemically converted or replaced with proper metal again. Mainly replaced.

But i have a few "minor" problems that i'm trying to get out of the way. 

First i have a check engine light on. I've shorted the plug under that glovebox, and the engine code 13 blinks. O2 issues.
So i changed the lambda sensor right after the manifold, to a Bosch universal. From my limited knowledge of a multimeter, i got the wires right. But the light stays on. Before i just start from one end of the vehicle going backwards to check everything. Does anybody know of a common issue with this faultcode?

Second i have an issue with a fuse blowing after about 1 hour of driving. It is the fuse for rear lights and speedometer light. 
I have been driving in both dry weather and wet weather, and the wet seems to blow it quicker.
A little side info. The car is missing the inner plastic lining for the wheel well, so a lot of water and stuff is being thrown up onto the inside of the rear bumper/fender. The lining is on the buy next list...
Also i am missing a bulb inside of the speedometer, and the speedometer gets very very hot, even when im not blowing hot air in the car.

My conviction of electrical problems on cars, is that only wizards and warlocks can troubleshoot properly on them, and im just a kings jester in this case. But i have heard that if you eg. swap the lights for LED, it might break a fuse because of the lower voltage something something. 
Also electrics and heat i have a hunch is not necessarily.
But how do i go about reading my multimeter and where do i stick it into, if i want to try doing magic myself?

Any tips, or common knowledge on either of these issues are welcome and received with great gratitude from me and The Wombat

Firstly there are a lot of knock off sensors out there that don't work no matter what. Secondly from what I understand the earlier cars are quite particular about sensors being correct and as expected. As for blowing lighting fuses the first question is does it have towing electrics as they are very vulnerable to moisture and shorts.

Yeah, it does have towing electrics, i just redid the wiring, so i might take that slightly apart and give it some electric spray, and some good tape after being dried properly..

Thanks a lot!

OliverH wrote:

Second i have an issue with a fuse blowing after about 1 hour of driving. It is the fuse for rear lights and speedometer light. 

My conviction of electrical problems on cars, is that only wizards and warlocks can troubleshoot properly on them, and im just a kings jester in this case. But i have heard that if you eg. swap the lights for LED, it might break a fuse because of the lower voltage something something. 
Also electrics and heat i have a hunch is not necessarily.
But how do i go about reading my multimeter and where do i stick it into, if i want to try doing magic myself?

Any tips, or common knowledge on either of these issues are welcome and received with great gratitude from me and The Wombat

LEDs draw less current than ordinary filament bulbs, so are less likely to blow a fuse.  Some LED lights have internal resistors to draw more current and if the rating of these is wrong for your vehicle, or they draw more current after been used a lot then this might be blowing the fuse.

Robin