CK5
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'89 R3500 Crew Cab 2wd to 4wd conversion & beyond

Started out with 2wd TBI350 with SM465 to current 4wd with 454, 700r4, NP241
Yes. Dumb ol' me didn't realize they came as a package of 1 so I only have the one; thought it seemed kinda cheap. Gonna order the other one tomorrow.
 
For those that have messed with TBI wiring; please advise. I have the harness unplugged from the ECM. There was a smallish plug that had to be disconnected behind the dash. Pulled the harness through the firewall.

There's the plug on the firewall at the driver side that my questions are directed towards. I can't just remove that plug with the rest of the ECM harness as it has stuff I still need like the the wiper motor, washer fluid, and the alternator wires. Plus the wires for the fuel pump and coil. I suppose when a person is pulling this harness for a TBI swap they are taking it out of a vehicle that won't be operated anymore. I'm assuming I could just unpin the unneeded wires from the plug and reconnect the plug at the firewall. Just curious how that bulkhead connection is handled when pulling the harness for use in a conversion situation.
 
For those that have messed with TBI wiring; please advise. I have the harness unplugged from the ECM. There was a smallish plug that had to be disconnected behind the dash. Pulled the harness through the firewall.

There's the plug on the firewall at the driver side that my questions are directed towards. I can't just remove that plug with the rest of the ECM harness as it has stuff I still need like the the wiper motor, washer fluid, and the alternator wires. Plus the wires for the fuel pump and coil. I suppose when a person is pulling this harness for a TBI swap they are taking it out of a vehicle that won't be operated anymore. I'm assuming I could just unpin the unneeded wires from the plug and reconnect the plug at the firewall. Just curious how that bulkhead connection is handled when pulling the harness for use in a conversion situation.
Pink w/ black?
 
Pink w/ black?
I did finally find the pink black. I was thrown off because the wires haven't exactly stayed color-true. I had to trace it back from the splice to the injector wires; then I knew I had the right one. Last thing is to verify that it's the right gauge to match the Sniper wire.

It looks like I'm only going to have 4 unused wires from the TBI harness that connect to the driver side bulkhead connector. Plus some random wire the previous owner cut that I have no idea what it's for. I've decided I'm going to cut them about a foot from the bulkhead connector and cap them off. That way they can be easily hidden in some loom and still usable if needed for some reason.
 
2017-04-02%2016.14.01.jpg




Are you going to run poly inserts?

I don't think his legs will provide enough torque for the poly to be needed.




:)
 
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Got an early birthday present from my father-in-law, the big 2000lbs trans jack!

2017-04-04%2014.07.01.jpg


Also need to replace the big wire that runs from the starter to the junction block on the firewall which ultimately feeds battery power to the entire truck.

2017-04-04%2014.13.56.jpg


That was how we found it when I first got the truck. Found it by accident getting a wrench up near the starter. ZAP! WTF!! I temporarily covered it with a little piece of hose and electrical tape.

Anyway, it has a fusible link. I'm not necessarily opposed to installing the new wire with a fusible link as well but I would much rather use a fuse. From my searching maxi fuses seem to be the popular choice to replace fusible link wire. The problem is I don't know what size I would use for a fuse. Can't really use the wire gauge because it's only 3ft long and in theory 8ga wire can handle a lot at that short length. The biggest maxi fuse you can get is 80amp so I'm debating about using that. Or just putting fusible link on the new wire. The entire wire is getting replaced.
 
My understanding is that you don't want to put a fuse where a fusible link is because a fusible link is intended to be a slow blow whereas a fuse just pops.

I also read that a fusible link is nothing more than a section of wire 4 gauges smaller than the rest of the wire. I wanted to buy a couple a while back and didn't have much luck finding any.
 
Run one of these, https://www.napaonline.com/en/p/BK_7823114 It is a type III circuit breaker. It's what we use on all of our utility trucks. No fuses to carry. It trips and then the arm swings out and you push it back in to reset. I think this is the common one Napa carries but check around cuz there are a lot of options and amperage ratings. Pollak makes them and Bussman.
NWMDC
 
IIRC, the fusible links are color-coded for amperage, i.e. a pink one is 50A (or whatever, I made that up.) You should be able to find an appropriate replacement of whatever type from the color of the one you have.

If you do stay with links, I swear Dorman or somebody makes them and you can get them at the parts house easy.

-- A
 
Circuit breaker isn't a bad option. I have found the fusible links. American Auto Wire makes nice kits. Summit has 4' lengths made by Pico.

The wiring diagram says it's 8ga with 12ga fusible link.

I did notice the Pico wire is indeed different colors. Curious if that crosses over to an amp load.
 
Cuz otherwise if catastrophe arises, the wire melts and catches fire. Same as a fuse or circuit breaker.

-- A
 
That one time though :angry1: fire bad...Just run a short length off the battery to the breaker then from the breaker run your wire to the junction block. The shorter the better on the unfused portion to the breaker. Avoid the starter altogether for ease of service in the future.
 
Napa should sell rolls of fuseable link. They are color coded to the amperage. IMO they are outdated old technology cuz nothing runs them any more. Plus they suck when they go bad and you can't tell.
 

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