80 sc fuel pump relay power source?

$yncro · 05-31-2023, 02:23 PM

Hello, I by passed my fuel pump relay power source 4 years ago.
The 4th fuse from the left not getting power to the FP relay so
I Hotwire with fuse direct to the battery. Car ran fine but double checking if it's OK? I finished Engine rebuild and pretty much rebuild the whole car. Just want
To make sure I put that power source back where it's supposed
To be. Can't remember where I spliced it from.

Anyway, here's some pics.
Thanks in advance.

$yncro · 05-31-2023, 02:44 PM

My mistake.. I took the red wire from the FP relay and connect it directly
To the battery with fuse. Now, where do I connect it back to? Is it the to the
4th fuse from the left?
Thanks

REVerend · REVerend's Garage

No idea… but here is the wiring on my 83 SC which, as far as I know, is more or less stock

REVerend · REVerend's Garage

A few more… if there is some other area I should be focusing on please advise

$yncro · 05-31-2023, 03:16 PM

Thanks for the pics.. i took a pic from the back side and pointed the
Red power wire with screwdriver. That's the wire I need to know where
It goes. If it's much of a hassle don't worry about it. Hopefully somebody
Will have an idea. Thanks again.
Ogi

83_Silberpfeil · 83_Silberpfeil's Garage

@$yncro - I read this thread a few times, but not understanding what you Q is.

Regardless, I'll share the relay/fuse diagram from my Bentley's manual. According to this table, for 78 ~ 80 SC's, the FP fuse is #16, 6ths from the windshield.

Quote:

Originally Posted by $yncro

Thanks for the pics.. i took a pic from the back side and pointed the
Red power wire with screwdriver. That's the wire I need to know where
It goes. If it's much of a hassle don't worry about it. Hopefully somebody
Will have an idea. Thanks again.
Ogi

$yncro · 05-31-2023, 05:46 PM

Quote:

Originally Posted by 83_Silberpfeil

@$yncro - I read this thread a few times, but not understanding what you Q is.

Regardless, I'll share the relay/fuse diagram from my Bentley's manual. According to this table, for 78 ~ 80 SC's, the FP fuse is #16, 6ths from the windshield.

I see what you meant, I was all over the map to explain my dilemma.
I'll try again. I need to know where the FP relay gets its power.

From this pic. (Backside of the panel) I pointed with screwdriver the big red wire that I connected to the battery With fuse to get power to the Relay. All the wires with that bundle goes to FP relay, I want to place that wire where it's supposed to be. I'll check the fuse #16.
Hope I made sense.
Thanks

timmy2 · timmy2's Garage

Bottom of Fuse 16, counting from the headlight. There should be a jumper to the top of fuse 16 coming from the top of Fuse 11

$yncro · 07:42 PM

I think I found it! Thanks for all the help.
Fuse #16 FP and gets power from Fuse #11
Only gets power when ignition ON. That's exactly
What I was wondering. Right now my fuel pump
Gets power +12v direct from the battery.
And I found the diagram from Bentley, thanks
Silberpfeil for the direction.

Dennis thanks! You beat me to it!

pmax · pmax's Garage

It's interesting how the wire connected to the top of fuse 16 appears charred, in both. Reminder to self ... check if mine's the same.

$yncro · 05-31-2023, 08:35 PM

Ok.. now I remember why I wired my fuel pump direct to the battery 4 yrs ago.
Because I'm not getting power from fuse #16 and #11 together.
When I crank the engine there's no power to the FP.
now trying to find where fuse #11 gets it power +12v.

timmy2 · timmy2's Garage

Fuse 11 gets power from fuse 12 red/black wire courtesy of the ignition switch via the rear brass strap on the fuse panel. Maybe that is your problem, the jumper strap on the fuse panel has failed.
Jumper is in your drawing, from f-12 to f-11. Line with connector dots inside fuse panel outline.

$yncro · 05-31-2023, 09:12 PM

Thanks Dennis, I'll tackle it tomorrow morning.

$yncro · 11:08 AM

K, I checked the brass jumper #11 & 12 it's intact.
Checked it with test light ignition on, still no power.
Cleaned all the fuse terminals too. However I did
See a loose wire at the back of the panel ( brown Red wire)
Screw driver pointing in the pic. Where is that wire
Connected?

Btw, my Hazards and lights are all working. I believe it's powered
By fuse #11. Should I just by pass the Fuel pump relay power?
Like what I did before..connected to the battery with fuse. My
Concern is that it's getting power all the time. Or I can put a jumper
Wire from fuse #13 to #16 instead.there's power at 13 once ignition on.
I believe it's for windshield wipers.
Thanks.
Ogi

$yncro · 06-01-2023, 03:09 PM

So..I jump fuse #13 to #16 to get power when ignition ON.
Fired her up and no problem. Car starts and ran fine. While running,
I put a test light to fuse #11 and #12 and it's getting power! Why is that?
When the engine is running There's power, when off and ignition on no power. How is it suppose
to deliver power to the FP if that's the case?
I'm just going to use the Fuse #13 to power my FP. Can't see why not.