Fuse link to maxi fuse equivalent

[135sohc]

I am installing a fuse & relay block from a 94 Lebaron into my 94 Shadow.

Using the Mini-Mopar page on this very subject has helped but its also somewhat out of date for later cars and somewhat goes against how the fsm lays things out.

I would like to keep the fires and melting wires from happening on my car so I am asking for the electrical experts and those (especially with a P body) who have done this upgrade to chime in on the ratings of the fuses they used.

Stock P body layout:

Hazard flasher, 16 gauge feed, 22 gauge fuse link

Ignition off draw, 12 gauge feed, 20 gauge fuse link.

Headlight switch, 12 gauge feed, 18 gauge fuse link

1st Ignition switch feed, 12 gauge feed, 18 gauge fuse link

A/C clutch & Radiator fan relays, 14 gauge feed, 20 gauge fuse link.

Alternator input, 8 gauge feed, 12 gauge fuse link

12 gauge wire spliced off the main bundle and it feeds 2 more fuse links:
ASD & Fuel pump relays, 22 gauge fuse link, 16 gauge feed to each relay

Starter Relay and what I call Ignition switch feed #2, 20 gauge fuse link, 12 gauge feed to the starter relay, 12 gauge feed to the igntion switch.


How I currently have it laid out. I am retaining the stock P body wire sizes and/or going up a size or two as necessary since I'm recycling some wires to use the terminals.

Hazard flashers are fed through a 20 amp mini fuse.

Ignition off draw is fed through a 20 amp mini fuse.

Headlight switch feed is going through a 40 amp maxi fuse. (Lebaron fuse box used a 40 amp maxi fuse for the headlights, and a seperate 40 amp for the parking lights )

1st Ignition switch feed is going through a 50 amp maxi fuse.

A/C clutch & Radiator fan relays are going through a 40 amp maxi fuse

Alternator input is split between two 60 amp maxi fuses. (exactly as the Lebaron fuse box was laid out)

ASD & Fuel pump relays are going through a 40 amp maxi fuse.

Starter relay and Ignition switch feed #2 are going through a 40 amp maxi fuse also.


There a two additional maxi fuse spots and 4 mini fuse spots left in the block should I need to split up anything ? Of course I will be drawing a schematic of the final wiring layout but I would prefer to maintain the factory feed configuration/breakout for simplicity reasons and I guess just because its worked this long, so why mess with success ?

I largely followed how the Lebaron fuse feeds were configured and adapted as necessary trying to error on the side of caution when it came to fuse size. I figure my base model P body is fairly low on the electrical demands compared to the loaded J body model but who knows ?

Thanks for any input

[135sohc]

http://www.powerstream.com/Wire_Size.htm

If thats accurate then I'm not to far off. I am going to pickup a clamp style multimeter tomorrow and measure the loads on the existing links/wires and use that to get a better estimate on exactly how much current is running through those wires.

[BadAssPerformance]

Interesting analysis. I'm no an electrical guy so I would guess a 20A fuse would be a direct replacement for a 20A fusible link?

[turbodaytona87]

Correct

[rbryant]

If you just put it in as it was in the jbody you will be fine. The wire colors should even match.

I did the same sort of thing but used the more common 1G neon PDC. The Neon PDC doesn't however have alternator fuses but that doesn't really matter because everything is fused after it anyway. I also have an inline fuse in the alternator feed before it anyway. BTW the colors still mostly match even between the early 80s wiring and the Neon PDC.

The 95 neon box uses a regular relay for the fan where the 96+ has it as an external solid state relay. I just rewired the 96 box to use the ABS fuse and an empty relay slot for the fan.


-Rich

[135sohc]

If you just put it in as it was in the jbody you will be fine. The wire colors should even match.
-Rich

Some do but alot dont. not to mention there are additional/different circuits on the Lebaron that the Shadow doesnt use. So its not that easy

Example, the rear defroster on the Shadow is fed through the IOD circuit and uses a 20 gauge fuse link. on the Lebaron its got its own 40 amp dedicated fuse circuit.

[135sohc]

Interesting analysis. I'm no an electrical guy so I would guess a 20A fuse would be a direct replacement for a 20A fusible link?

Thats the problem. Fusible links arnt rated in amps like a fuse.

[rbryant]

Some do but alot dont. not to mention there are additional/different circuits on the Lebaron that the Shadow doesnt use. So its not that easy

Example, the rear defroster on the Shadow is fed through the IOD circuit and uses a 20 gauge fuse link. on the Lebaron its got its own 40 amp dedicated fuse circuit.

The wires should still go to the same places from the battery/alternator, etc to the 50 pin bulkhead though so don't overthink it.

The cars are pretty much the same and if anything the lebaron (espcecially one with a PDC) would have more accessories so I would suggest wiring the shadow exactly as the lebaron was. There will likely be extras that you can do what you want to with but the basics should be the same.

For the rear defrost just cut the wire before and after the link and run it through the lebaron PDC. The PDC should remove ALL fusible links IIRC.

Even when using the neon PDC in an lbody the fuses matched the links I replaced perfectly. The only extras were things like interior lights, horn, etc that have their own fuse on the interior of the car rather than under the hood. The extras are still handy as extra fuses now. Interior lights will become an under hood light, etc.

Why isn't it that easy?


-Rich

[135sohc]

The wires should still go to the same places from the battery/alternator, etc to the 50 pin bulkhead though so don't overthink it.

The cars are pretty much the same and if anything the lebaron (espcecially one with a PDC) would have more accessories so I would suggest wiring the shadow exactly as the lebaron was. There will likely be extras that you can do what you want to with but the basics should be the same.

For the rear defrost just cut the wire before and after the link and run it through the lebaron PDC. The PDC should remove ALL fusible links IIRC.

Even when using the neon PDC in an lbody the fuses matched the links I replaced perfectly. The only extras were things like interior lights, horn, etc that have their own fuse on the interior of the car rather than under the hood. The extras are still handy as extra fuses now. Interior lights will become an under hood light, etc.

Why isn't it that easy?


-Rich

I have the 94 fsm (actually 2, one opened to each section) and just comparing wires and whats going on with each particular setup. The shadow is just flat out old school simple. fuse link to wire to function. On the lebaron its got one fuse feeding primary and a branch off feeding a second fuse. 2nd fuse powers a relay and branches off to go somewhere else and on it goes.

I probably am very overthinking this but I also want to do it once, do it throughly and not wonder if theres going to be a fire just waiting to burst out from something not being right.

[rbryant]

I have the 94 fsm (actually 2, one opened to each section) and just comparing wires and whats going on with each particular setup. The shadow is just flat out old school simple. fuse link to wire to function. On the lebaron its got one fuse feeding primary and a branch off feeding a second fuse. 2nd fuse powers a relay and branches off to go somewhere else and on it goes.

I probably am very overthinking this but I also want to do it once, do it throughly and not wonder if theres going to be a fire just waiting to burst out from something not being right.

I only have the FSMs up to 91 and I don't see the PDC in it.

If you scan it I will take a look.

I think you will find however that the relays are simply connected behind the fusible links in the shadow in an electrically equivalent way to what you are seeing in the PDC.

Remember that all of the wiring to the relays is self contained in the PDC.

-Rich

[black86glhs]

I feel your pain. I'm adding a PDC to my GLHS. I have most of the wiring worked out, but until I get the PDC in the car, nothing is 100%.

[iTurbo]

I did it the 'easy' way on my SL. I just dropped a whole harness in from a '91 Lebaron GTC convertible. It included the PDC so I really didn't have to rewire anything at all except the bulkhead. On my SL, the PDC is pretty vacant compared to the GTC which was convertible, totally optioned out etc.. The SL and GTC are very similar body-wise so that approach worked pretty well for me but I can see how it would be more difficult on a P-body and it sounds like you are grafting it in to your existing underhood harness. Sorry I'm probably not much help but can't wait to see how it goes for you. I'm going to be using a Neon PDC in a wiring harness I'm working on. I have wiring diagrams from the public library ("Mitchell" not FSM) and it does appear to be pretty straightforward swap.

[iTurbo]

Here's the PDC in my SL. Is this the same one you are using 135sohc?

[135sohc]

Thats the one I'm using (or hoping to anyways)



Like you described the Lebaron is/was fully loaded. And since the J body was also more electronically 'advanced' using a BCM and other things that the P body doesnt have. Its not just this 'match up and go' like everyone describes it being. I am grafting it into the existing underhood harness. since the Shadow doesnt have one of those bulkhead style connectors like all the other car bodys did...

Another thought. Getting some spade terminals and crimping, soldering them onto a short piece of fuse link wire of the appropriate gauge and plugging those in as fuses ? Couldnt be wrong then

[iTurbo]

I wouldn't think the BCM would be an issue. I know my SL doesn't have it and it was pretty easy to make the GTC (which did have it) harness work anyway. IIRC it had two wires for a "CCD bus" that go to the bulkhead, but on my SL they just stop at the bulkhead and don't go anywhere.

Have you got the entire '94 Lebaron harness or did you just cut out the PDC with some wiring to splice onto? I would think if you took it one circuit at a time starting with all the power feeds and then relays your P-body is actually going to use, it should be pretty straightforward. There will likely be some vacancy like on my SL because it isn't optioned out like the J-bodies commonly are.

I have wiring diagrams for a '91 GTC and my '87 SL. Looking at the diagrams, the power distribution/feeds really aren't that different between the two even though SL originally had fuse links and the GTC had the PDC of course.

[marc]

Fusible links are size by going 4 number sizes smaller then the wire its to protect. Example: 10 gauge wire would be protect by a 14 gauge fusible link.

[TurboII]

So, how hard was the swap, im in the same process. i have the same exact fuse box off a 94 spirit ( same as lebaron, shadow..etc).

im installing this in my 88 baron.

Joey

[chilort]

I used a Lebaron PDC in my '86 Daytona. It really was almost wire for wire. I showed this to Force Fed Mopar (Rob) on Thursday last week. I only had the '86 FSM and simply used my DMM to pin out the PDC. Colors were almost 1 for 1. I actually left all of the old '86 relays attached but in the future I may wire them up through the PDC. Because all of my old relays still work and I have full set of spares I just didn't worry about it.