How to rewire FSS/Injection Pump

[idiabuse]

I have been rewiring vehicles lately that have pumps/fans that did not use relays.
You cant run electrical component's without proper sized wires and properly placed relays.

Current flows just like diesel fuel, it dont like sharp corners and small lines...


Javier

 

[rhkcommander]

Put a toggle switch in the dash, run 12v to it from either fuse panel or battery. Other wire to fss. Now its more like a tractor. BUT easier to steal. Really you just need a pair of pliers to take one...

I would suggest you also add two more buttons, these will give you full control of your truck: pushbutton for starter, and pushbutton for glowplugs. The pushbutton starter will keep you from snapping the crappy actuator in the steering column. I prefer to be in control of my glowplugs - manual truck with manual everything else - why not? I can run Bosch plugs manually and not burn them out whereas your pretty much stuck with Beru on the controller. Radio is switched off of constant 12v too so i can listen to it without keys.

Its really weird that it kept melting wires. On the passenger fender is a big gray connector with 8 or so wires. The red wire with green stripe is key-on power for all that. Its common for this to be corroded, dirty, melted, broken, etc. If its shorting out there the wires would melt before the connector. I dont recall if you said it was right off the IP or further back...

Bad connections including internal wire damage can cause arcing which gets hot, smoking, etc. While you are replacing wire you could get a diode, and do the high-idle switch modification too.

 

[84IDI-BERTHA]

No worries man, I have the same issue even explaining in person!!!

 

[84IDI-BERTHA]

thanks for the info guys. I finally finished pulling the plugs, which were a pain in the a$$. I ended up having two broken tips, but must have passed long ago as they were all carboned up and dirty. 7 autolites and 1 ac-delco plug. only one autolite was slightly swollen, but came out no problem. I knocked on every piece of wood I could touch in the garage, after each plug came out. hahaha

But now that that is complete, I am going to wire in the manual switch tomorrow. I have a switch wired in for the FSS. Now it is the getting used to switching it on before driving, etc. A few times I let out a slew of curse words before realizing I didn't turn on the fuel. :

The wire was melting on the connector side opposite the IP. The wires running from the IP were fine, would get a little warm to the touch, but nothing to the point of melting. I looked inside the connector, and it looks slightly charred and dirty so it must have been a bad connection. But now that I have the switch in there, I won't worry too much.

I will try to post pictures tomorrow of the plugs so you can all see how lucky I was. Y'all rock, all the info on here has me confident to work on my ol' girl without worry.

 

[Fordsandguns]

Are you sure that the wiring isn't still shorting? What I mean is, if your FSS jumper isn't shorting, what was causing the short in the factory harness may still be there.
Which connector did you look at that looked charred? You shouldn't dismiss it until you know for sure that you have the cause fixed. You could lose your truck to fire.
I don't mean to sound smart alecky, I just want to save you from more problems.

 

[84IDI-BERTHA]

No worries, I know you're lookin out. I appreciate that. I went ahead and wired in a manual switch for my FSS. Completely rewired it, bypassing the 8 wire connector and mouting a switch in the cab next to my GP Manual Switch I just hooked up.

The connector I looked at was the connector that had the melting wire. The slot in the connector with the slight charring ( it looked like someone held a lighter to it, a little soot sort of) was the connector with the red/green stripe wire going to my FSS. The actual wire from the connector to the FSS was fine, it was the side of the connector with all the wires leading to the Cab that melted/shorted out. It looks to have been replaced by the Previous Owner, guessing it was a quick fix at the time and just took a dump on me. Not sure if it was the connector gone wrong, or his hack job.

Now that I bypassed the connector completely I have not had any issues, thankfully.

 

[rhkcommander]

If i had to guess, either a strand of wire or a bare spot was arcing, or the connection was poor an had arcing there

 

[idiabuse]

no 30amp relay was used in wiring up a fuel pump? I would never do that unless it was for testing components. good way to burn out expensive components.

 

[rhkcommander]

Most switches are good up to 10 amps some less some more. But from what i recall the FSS Draws very little.

A 30 amp Relay is way overkill unless adding a electric lift pump to it too. A fuse wouldnt hurt though

 

[Fordsandguns]

no 30amp relay was used in wiring up a fuel pump? I would never do that unless it was for testing components. good way to burn out expensive components.

He was just putting in a switch to the FSS on the ip, not putting an electric pump on it. A fuse would be a good idea but I don't think a 30 amp would be needed for the FSS.

On Edit: I said fuse but should have said relay. I guess there is more evidence of my jumbled thoughts!

 

[jim x 3]

Find and Fix the short causing the original problem

Bertha,

If you had an overheating wire with melting insulation, then you had a short somewhere. I'm with Fords and Guns, you should find the original problem and fix it.

Are you sure that the wiring isn't still shorting? What I mean is, if your FSS jumper isn't shorting, what was causing the short in the factory harness may still be there.
Which connector did you look at that looked charred? You shouldn't dismiss it until you know for sure that you have the cause fixed. You could lose your truck to fire.
I don't mean to sound smart alecky, I just want to save you from more problems.

Your coolant temp switch might be OK, you may have just overtaxed it with the short. In your first post you said the FSS was the issue. But you disconnected the FSS from the problem circuit and "everything's OK". So the FSS is NOT the issue, the wiring or something else in the FSS circuit is the problem. Get a wiring diagram (at least of the FSS - FIS circuit) and a VOM (multimeter) and you can track down the problem, fix it, and return to the stock configuration (which seems to work just fine for most of us).

Regards,
Jim