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Not quite out working under the hood just yet, but as I was out installing the rebuilt heater box, and pondering the under-hood work, I saw this terminal on the fender apron. Did a little searching around here, but just to be sure (I've not got out the voltmeter yet), I assume this is just a junction block for these three (make it four) wires? It's looking a little ratty, so before it breaks and shorts everything out, I'd like some insight as to whether I'm right about this thing. Thanks-
Horizon & Sound Ford in Renton are owned by the same guy. He also owned Millennium Ford in Burien (now closed).
Ed Olson, a long time pal of mine (originally from L/A) was the p/m at Horizon, had a stroke in 2011, retired. When Ed was there, it was partsguyed.com
Thanks KO and ND. I test-drove a 2012 Transit at Horizon Ford. They're a Ford Truck dealer as opposed to a Ford anything dealer.
If it's just a junction block, which is what I suspected, I'll just fab up another one. I can make it better. I have the technology.
Could be wrong, believe the 'junction block' is only used when the truck has an 'alt' gauge; if the case, suggest ensure circuit is intact and secure. Not an authority on auto electrical circuitry so when I installed an 'alt' gauge in the 65 decided to go with a 50 amp fused block purchased at local auto parts store. I had concerns about running many amps from the alternator to the gauge, or instrument cluster in general. Having said that, the junction block was installed over 40 years ago with no problem. Anyhow, food for thought??
Here's a link to an aftermarket part for anybody without the skills of DoubleOh7 or the time - Catalog which I "borrowed" from a year ago post.
Just a note to add to the conversation - my junction block (on a Custom Cab) failed, the insulator broke and allowed the pictured leads + one more to contact the fender. The result was fried instrument cluster wiring and an artfully smoked and customized ammeter guage, which I replaced with a used one from a marine supply house ($4.99 I think). Many, many hours to rewire - I'm no expert.
The point is: I believe everybody should replace this part. The insulator is brittle, as pointed out above, and is subject to failure anytime.
Hope this helps someone, thanks to all for your contributions to this forum, I could not have kept my F100 running without all of your input.
Without doing more than seeing it and taking the photo of it (in the dark) it appears to be a fairly thin phenolic insulator plate with a 5/16" carriage bolt coming up from underneath. Not even much protection from the two screws fastening it to the apron. Even so, I too saw: break, short, burn, cry - in that order.
I'm pretty tech savvy having made my own wiring harnesses or repaired them for more vehicles than I care to remember. It'll take me a few minutes to make a new one once I dig though my bins and scour up the parts needed to make it, best guess. But I don't like the design (even if it might last another 50 years if I got a new one) and will make it impossible to break and short against the fender apron. Save the tears for more important things.
Could be wrong, believe the 'junction block' is only used when the truck has an 'alt' gauge...
I did just a little tracing of the wires last night (it was dark and cold out there) and figured it was to power the ammeter. This truck has the idiot light and ammeter if I recall correctly. Been a couple weeks since I finished restoring the instrument cluster, but I seem to recall that's what it had. It's going back in very soon, so any of these little wiring issues will be resolved before I ever turn the key again.
Also, I always use an amp meter between the battery and positive terminal of the battery (or a 12 volt light bulb) to see if any current is flowing against a load before hooking up the BAT cable to the + BAT terminal. If I have any current flowing I pull all the fuses first to see if it goes away. If so I check for further shorts. If not from the fused items I dig into harnesses. Fried harnesses make for a very bad day.
I had no idea that the junction block was available, but I wouldn't use the stock piece. I used something like this: JB3816-2 Cooper Bussmann Junction Black .87. Lower cost, and I believe a better product. You will have to drill out, or change, the connectors for the larger stud size. Good luck.
I still lean towards the 'fused block', posting for pic only: I went w/ a 50 amp, should be able to purchase in any flavor; if decide to go this route, imagine most auto parts stores would carry fused junction blocks?? Purchased at local auto parts store which happens to be CARQUEST for $6.75.
Haven't traced it all out yet - may look at it tonight a little - but since these wires are at potential to fry all the way to the dash, then a fused terminal would be a good idea. Certainly don't need to be fully exposed to potential shorts.
I've redone plenty of engine-bay and under dash harness repairs because an unfused wire shorted and let the smoke out. They put no protection from the battery to the fuse box until... probably about the time they decided to add dual master cylinder brake systems.
As mentioned in my truck thread I did finally throw these together last night. Made a couple extras while I was setup to make them, so I have two available to anyone who might need them. Let me know if you're interested.
They're made from thick phenolic insulator plate and should last a long time. The bolt is stainless and when I can get to the hardware store I'll get some stainless nuts too. They have the same spacing as the original, so should mount right up. I'll replace mine this weekend.
As mentioned in my truck thread I did finally throw these together last night. Made a couple extras while I was setup to make them, so I have two available to anyone who might need them. Let me know if you're interested.
Do you still have one of the extra junction blocks that you made? I just discovered what this part was in my thread here ( https://www.ford-trucks.com/forums/1...l#post15836071 ) and I'll be needing a replacement. I don't think I can PM here yet, because I'm so new. Let me know!
12-16-2014, 09:46 AM
