“Hot” Side of Fuse Block? (Wideband Gauge Install)

[Phlown]

Hi All,

I am installing an AEM Wideband Gauge to my 1980 Porsche 911 SC. Gauge is mounted, Power wiring and UEGO sensor harnesses run, ready to connect Switched Power wire and Ground wire, then on to testing. (As an aside, many thanks to forum members who have contributed great info on installing Wideband Gauges. Searched, read through several threads that helped immensely.)

Feel a bit stupid asking A very simple question that I think I know but want to verify - Which side of the fuse block is “Hot”? From info gained mentioned above, I’m considering tapping into Hot side of Cigarette Lighter/Blower Control Light Fuse (Fuse #7 or 15th from the Front, depending on your numbering preference) and runnng 10 amp inline Fuse to Gauge Power wire.

I guess since I’m here posting, what do you in the know think of that plan? Is there a simpler, no inline Fuse approach others have successfully used? And Lastly, suggestions on best connection spot for the Ground Wire?

Thanks in Advance,
Phil

[steely]

Verify this but I think generally speaking the hot side would be the top, at least that's what it looks like in my '87. The buss-bars / bridges are a big clue.

I like the idea of installing a wideband, but have never done so, so I can't answer your other questions, but am sure you could find some hints if you search.

[timmy2]

Top is hot, bottom is fused.
There is a ground stud behind the gauges.

[T77911S]

if ever in doubt, remove the fuse, use a test light and ground the clip then check top and bottom.
test lights are also good for checking fuses.
like on the bladed ones. ever notice the little metal part on top of the fuse.
no need to remove them.

[ChrisHoover]

Originally Posted by T77911S

if ever in doubt, remove the fuse, use a test light and ground the clip then check top and bottom.
test lights are also good for checking fuses.
like on the bladed ones. ever notice the little metal part on top of the fuse.
no need to remove them.

Best advice: always check it to make sure. A volt meter to B- and to each side of the fuse block with the fuse fuse removed will tell the tale.

[Lyle O]

When I wired my gauge I used the power window circuit for hot, with a 5 amp in-line fuse (if memory serves properly). I grounded to the under dash common ground. Works perfectly, but the lighter/blower circuit should be fine I think.

[Phlown]

Thanks much for all the posts. Headed out soon to my garage to finish up the install!

[scarceller]

Another tip, these WBO2 gauges can draw a lot of power. Be sure you find a solid good ground point.