512tr fusebox problem...anyone want to play?

I got around to inspecting my 512tr fusebox. This was replaced back in the early 2000s.

I ran across the following.....look at the center black connector. It appears that both of the blue wires are seeing too much resistance. Counting over left to right you will see Wire #6 and wire #8 (they both are blue..the black is the discoloration)


So let the games begin.....anyone want to guess what these blue wires do?
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here is a better view
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The Fig 8 schematic in the 512TR WSM indicates that they supply +12V power to run the water radiator fan motors:

wire 6th from left = LN = blue/black

wire 8th from left = L = blue

The problem isn't resistance in the wire itself, but either unwanted resistance between the wire and the metal terminal that it is swagged to or (more likely) unwanted resistance between metal terminal on the end of the wire and the mating metal terminal on the PCBA -- the I^2*R heat generated at the bad connection (is significant, for even a very small R, because I = something like ~10A, and) gets conducted up the (copper) wire and fries the insulation. You should unplug the connector and inspect the metal terminals and the PCBA for similar thermal damage.

 

Thanks for the info Steve....is there a page in the workshop manual that identifies the numbers on the diagram.

I found page L32, but is there a page L31? Thanks.

 

I don't know -- but I hope there is somewhere . The scan of the 512TR WSM originally had nothing at all for the item numbers on the schematics, but then an FChatter provided page L32 (so Ben added that one to the .pdf file). If someone else has more, please post it, or send it to Ben Deetman to be added.

As you noted, there are no descriptions for items 01510, 01511, nor 03028 on page L32 -- but you can trace the L and LN wires back to relay H and relay L on the PCBA and those are described as being for the water fan motors so I'm fairly sure about that. Also, the large "2.5" wire size given for the L and LN wire corresponds well to large current that these motors draw.

 

I am trying to understand this circuit....and as always...you are a huge help.

It seems like I could move the relays and fuses to an ancillary box and keep the power off of the circuit board.

What I am trying to understand is if the temp switch on the radiator energizes the relay or if it simply closes the circuit and let's the current flow.

 

Yes, this is essentially how the SRI fix works. The other option is to run a new (high-current capable) wire directly from the output (87) terminals of relays H & L to the L & LN wires (bypassing the connector on the PCBA).

The former -- the temp switch 03028 in the radiator closes and energizes the H & L relays which then close and run the water fan motors. The water fan motor currents required are far too high to pass directly thru the temp switch.

 

Guys, sorry just a quick question while on fuseboxes...I am going to look at a few cars shortly. Where is the fusebox located? Is there anything to be seen looking at it "as is" or does it have to be removed?

Many thanks!

 

Yes, it's being done in Colorado with 6 or 7 high amp circuits. This includes 512TR's
Innovations - Solutions - Scuderia Rampante
Many of us on the site have had our fuse panels modified already.
Including this guy, http://www.ferrarichat.com/forum/boxers-tr-m/397935-another-fuse-box-going-colorado.html#post142114526

 

On TR's it is located on the aft bulkhead, under the front bonnet.
It's behind a carpet covered access door.
Just undo a couple of 1/4 turn fasteners with your fingers and the top of the panel should swing forward.
Ideally an inspection of all four large white connectors along the bottom of the fuse panel would be recommended. You want to look for brown discoloration and melting.
Unplugging all four and looking at the face of each is highly recommended.

 

Thx for that!

 

Bussman Fuse/Relay Box Kit from WagonGear - Expedition Portal

Looks like the parts are in the sub $100 range for this kit.

 

Can you get me one Tim ? I would love to join you with this upgrade .... cannot find it in Holland ...

Does this photo look familiar (not mine) .................
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here is a color coded diagram....

you can see that the full power of the fans (pink and blue lines) are triggered by the green labeled wire from the radiator switch closing the relay.
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I already "took away" the powerleads to the front lights and horns ... so the fusebox (10500) doesn't have to deliver more than just an input signal to the relays.

And what about that brown cable, it gave theunissenguido a scare ...

That brown cable (with black tape) is the lead to the fuelpumps he said ... (is this correct ? is there only one ? Should there not be another one ? fuses 18&21 ... ) ?

H connector (30017), cable # 1 ; which is the other one please ? This cable gets his power from relay G ...

He had to buy a new 512TR fusebox because this cable/connector melted away the spade terminal already ...

So ... it seems the 512TR gets its issues now also .... lets face it ...


But I like to join in with the new WagonGear idea Tim !
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Had a time-out here sorry ...

Imo, the brown cable in connector H is the airco unit ... and the airco get power through this relay G from fuse # 5.

We should find an electrician here that can make us a proper scheme for updating this fb; out should go: 2 x fuelpumps, 1 airco and 2 x fan for watercooling imo.

 

I agree....the fuel pumps are continuous. The fans and ac draw a substantial amount of power so I agree with you completely....move all of these.

I want to add a point that Steve told me that I find very valid.......it is the crimped connection on the wire that exits the board that causes the resistance and heat build up. The board by itself is not bad. If the outside wire heats up it transfers the heat back into the board. (Im trying to say the heat goes back into the board instead of being generated by the board)

Anyways, I think that an outside fuse box that has the relay and fuse for these large items would save the board. This outside relay should be readily available and inexpensive so that it can easily be replaced and not involve replacing an expensive fuse panel.

Anyone wish to track down the AC or fuel pump circuit?

 

Do you have the digital picture ? ... I can send it to you .... ([email protected]) or use the smaller version above.

What we should find is where to get the signals out from the 5 relays... and connect those 5 leads in a separate WagonGear ... sending that power to the units ...

Would you be so kind to send me one WagonGear if you do the job in your car please?

 

Melvok...you can order the box in many locations. It is a cooper bussmann 15300. A quick google search will show many locations and uses.

My neighbor and I were thinking about this tonight and came up with a new idea. Since my fusebox works (I found my problem before any effects occurred) we will use the cleaned up contact points to serve as the new "switch" to power the external relay and fuse on the bussman unit. This way all of the ferrari panel relays in the car will work correctly and carry a much lighter electrical load through the panel board.

The only drawback that I see is having 2 relays to possibly troubleshoot if there is a problem. However, the stock Ferrari fuse board will no longer be carrying all of the high amp load....it will simply serve as the switch to the external relays. (Make sense?)

The bussman unit has 5 relays....2 for the radiator fans, 1 for the AC, and 2 for the fuel pumps. I see assembled units on eBay which would be much cheaper than a new Ferrari fuse panel. I ordered one and will see what the fit looks like.

 

Hi Tim, looked everywhere here in The Netherlands, Germany ... cannot be supplied here ...

If you have fixed it and are happy; can you get me one please ?

Greetz Mel

 

Already news Tim ?

 

Just received the goods in the mail today. I will not be able to get to this project for a few more weeks, but will update you then.

 

I confirmed that the brown wire in your photo IS the AC.....(did a continuity test on my fusebox)

My relay panel fits in the compartment on the passenger side where the AC drier sits. I am running a separate panel that will keep the 1) AC 2) left hand radiator fan and 3) right hand radiator fan high amp circuits out of the fusebox.

Do you think the fuel pumps are necessary? I do have room for 2 more relays. Each relay can handle 35amps.

 

Most definitely, the fuel pumps draw heavy current. Add the oil cooler fan also. 6 circuits is what they normally isolate from the fuse box.




Ago

 

Agree fully with David / Ago ... I intend to also do the pumps ... So if only 5 new relays are available, then I woud skip the airco fan ...
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