Wiring help needed

[fummins97]

1976 Bronco with 1998 Explorer 5.0and 4r70w, efiguy motor harness and centech harness.

Just need a few questions answered and maybe I can finally get this thing done.

Centech-White-Coil+-----?
Purple-Start----?
Blue-Ignition---?

Orange-has "wiper radio" and "wiper switched power" wires?

Grey-Cigar----can this be hooked to a power point for phone charger?


Efi harness--

Trans harness-
Reverse light swtich---Prpl/Or-hot in run---self explained!
Bl/Pnk-power out to reverse lights--run a wire back to the pigtail itself???

Nuetral Saftey switch-Pnk-hot in start from ign swtich--does this go to the centech Violet start wire?
Tan/Rd-start signal out to solenoid--goes to "S" terminal on solenoid?

Engine Harness-

Prpl/wht--high idle switch--any idea how many amp switch this should be?

Thick red wire--ignition swtich hot in run and start---where does this attach on the ignition?

Rd/grn---Brake light swtich(hot when pressed)---does this attach on the actual brake pedal switch?

Grn/rd---Charge light----anyone find a light for this?

Then I have all these lights and switches that require a hot in run wire to power them, should they all be fused? how many can I wire together without overloading the wire? I have the "choke", "Distributor" and "idle sol" wires that I won't be using because of fuel injection, are these usable for those said lights and switches???

One last question, the fuel injected motor I took out was from a 88 crown vic with a distributor. It had a MSD box, coil and wires. This motor uses the coil packs, is there no need for the ignition box? Just curious, I am very inexperienced with electrical and fuel injection.

All that being said, I'm no mechanic by any means, I research and try my best and friends and forums like these are a tremendous help. Appreciate all the help over these last few months!

 

[fummins97]

Can anyone answer any of these??

 

[JAFO]

Wish I could help but I installed a Centech harness on my stock 73. Have no idea for a 98 5.0 engine swap. Sorry.

I guess you have the manual that came with the harness? If no, it is here....
It does spell things out fairly well. I was able to wire my whole Bronco in a couple days using this manual.

https://classicbroncos.com/img/tech/Centech-Complete-Instructions.pdf
https://tomsoffroad.com/

Regarding the Coil+, that is hot while running, so I guess it would feed whatever gives the 5.0 spark, but just a guess.

I think the red/grn brake light switch you are referring to is the brake WARNING light, which is not your brake lights. The brake light switch wires are two white wires I think, which can connect to either side of the switch that is up near the brake pedal arm.

I have not to date hooked up my brake warning light wire, though I do have the brake warning lamp in my dash. I was considering a parking brake warning instead, but have not totally decided on how I want to hook up a parking brake warning switch. Still considering options.

I wired my Orange Cigar wire with a split so I could feed my radio and also the cigar socket that is at the base/underside of my dash. That wire is plenty big for that purpose. I think my thought was to keep the wiper motor by itself in case of noise.

Regarding using the unused wires for other purposes, it comes down to wire size and amp draw.
This site is helpful for determining how many amps a given wire can handle. Depends on size and distance run. You would need to have an idea of the sort of load is being pulled by what you are energizing. Lamps wouldn't be using many amps.

https://www.tessco.com/yts/industry/products/itm/automotive/get_wired.html

I think with all the wiring I had the most problem getting the turn signal wires straight. I had to ohm the new switch to figure out what went where on the connector. Here is a link to my findings on that....

http://classicbroncos.com/forums/showthread.php?t=260944&highlight=Centech+turn+signal

 

[904Bronco]

1976 Bronco with 1998 Explorer 5.0and 4r70w, efiguy motor harness and centech harness.

Just need a few questions answered and maybe I can finally get this thing done.

Centech-White-Coil+-----?
Purple-Start----?
Blue-Ignition---?

Orange-has "wiper radio" and "wiper switched power" wires?

Grey-Cigar----can this be hooked to a power point for phone charger?


Efi harness--

Trans harness-
Reverse light swtich---Prpl/Or-hot in run---self explained!
Bl/Pnk-power out to reverse lights--run a wire back to the pigtail itself???

Nuetral Saftey switch-Pnk-hot in start from ign swtich--does this go to the centech Violet start wire?
Tan/Rd-start signal out to solenoid--goes to "S" terminal on solenoid?

Engine Harness-

Prpl/wht--high idle switch--any idea how many amp switch this should be?

Thick red wire--ignition swtich hot in run and start---where does this attach on the ignition?

Rd/grn---Brake light swtich(hot when pressed)---does this attach on the actual brake pedal switch?

Grn/rd---Charge light----anyone find a light for this?

Then I have all these lights and switches that require a hot in run wire to power them, should they all be fused? how many can I wire together without overloading the wire? I have the "choke", "Distributor" and "idle sol" wires that I won't be using because of fuel injection, are these usable for those said lights and switches???

One last question, the fuel injected motor I took out was from a 88 crown vic with a distributor. It had a MSD box, coil and wires. This motor uses the coil packs, is there no need for the ignition box? Just curious, I am very inexperienced with electrical and fuel injection.

All that being said, I'm no mechanic by any means, I research and try my best and friends and forums like these are a tremendous help. Appreciate all the help over these last few months!

Ok I will give this a shot... I have a 98 Explorer EFI Guy set up with a Centech harness in my 68.

White coil wire - not used
Blue Ign wire - not used
I left them terminated in the 3 wire weather-pack connector and put heat shrink over the end.

Purple start wire - has to be routed through the neutral safety switch in the transmission and back to the starter solenoid. On my harness, Garry ran the wires for that to the pass fender, where his fuse block is in the harness.
Where are yours terminated at?

Orange wire - Those two items are on that circuit, use it for radio power.
Grey wire - Cigar, yes use it for the Cig lighter or a power point.

Centech lower/rear body harness has two grey wires that go to the back up light circuit. (on drvs side) One is hot that goes to the rev switch on the Trans side and the loops back in the harness to the lights. Garry terminated the wires for the back up switch on the tranny right near the large grey plug. I used a weather-pack connector to joint the the two harnesses there.

I believe that the tan/red start signal wire is attached to my "S" terminal of my starter solenoid. (It has been a while...)

Purple/white - High idle - I do not have that? But I believe it is a momentary on switch that signals the ECU with 12v to bump up the idle. Just like the O/D switch. It does not need much amps 3-5 would be good.

Rd/grn---Brake light switch (hot when pressed)---does this attach on the actual brake pedal switch? Yes it does, non hot side of the switch. Centech wires are white if I remember. Use a test light to determine which is hot.

Thick red wire--ignition switch hot in run and start---where does this attach on the ignition? I will have to check my bronco - will reply later......

Grn/rd---Charge light----anyone find a light for this?
If it is terminated at the dash you can use it as an idiot light to tell you that the charging system is not working correctly. There is an accompanying resister needed with the 12v light. I am pretty sure Garry does not include the resister. You could not use it if you have a volt gauge.... put shrink tube on the end and pinch it off.

Then I have all these lights and switches that require a hot in run wire to power them, should they all be fused? how many can I wire together without overloading the wire? I have the "choke", "Distributor" and "idle sol" wires that I won't be using because of fuel injection, are these usable for those said lights and switches???
I would take a wire off the ign switch inside to provide power rather than run wires back from the engine compartment.... How many switches do you have besides O/D, Check engine, High idle.

One last question, the fuel injected motor I took out was from a 88 crown vic with a distributor. It had a MSD box, coil and wires. This motor uses the coil packs, is there no need for the ignition box? Just curious, I am very inexperienced with electrical and fuel injection. No MSD box with Explorer distributorless ign.

Hope this helps, I will be back to this later...

 

[904Bronco]

So all my wires requiring a source, like power at start or in run come from the ign switch, behind the dash. I might have even found a few unused wires on the centech harness to get what signals I needed. Short of pulling the AC ductwork out that is the best I can tell you.

That red/tan wire is not connected at the solenoid. Just power to Garry's fuse block for the EFI and the aforementioned purple wire coming from Centech >the EFI harness and back to the solenoid.

Enclosed is a break down of the Ign switch wiring. And charge light indicator

"Then I have all these lights and switches that require a hot in run wire to power them, should they all be fused? how many can I wire together without overloading the wire? I have the "choke", "Distributor" and "idle sol" wires that I won't be using because of fuel injection, are these usable for those said lights and switches???"

These wires are supplied power through the Centech harness, probably on the same fuse. You would need to do some testing (with test light) to find out which fuse, how big, and what else it powers. They could be used for other things, depending on what you find from the above testing.

This is where it would be nice to have a Centech wiring harness breakdown :-[

 

[fummins97]

thanks for the reply's. 904bronco to answer your questions, I wired the purple "start" wire that is bunched together with the yellow, red, white and green wires to the "s" terminal on the solenoid, I then ran the extra length of that wire down to the Tan/red wire that is on the neutral safety switch. I then noticed that there is another purple "start" wire that is included in that 3 wire weatherpack connector, I know you said to run that one to the solenoid but I'm unsure now.
the high idle switch was a option, its something to do with a/c and I think I remember your build having a/c so maybe that's it. I had him put it on there just in case I run a winch or snow plow someday. I bought a 20amp momentary thinking it would need some draw but I'll grab a small one like you suggest.
I think I will just cap off the charge light as you suggest, one less thing to hook up.
I have check engine light, idle switch, overdrive light, overdrive switch, brake light switch and charge light, so I will have to hook up my battery and start checking for power in those extra wires I talked about.

This should give me a good nights worth of work at least, thank you very much for the continued help!

 

[fummins97]

So all my wires requiring a source, like power at start or in run come from the ign switch, behind the dash. I might have even found a few unused wires on the centech harness to get what signals I needed. Short of pulling the AC ductwork out that is the best I can tell you.

That red/tan wire is not connected at the solenoid. Just power to Garry's fuse block for the EFI and the aforementioned purple wire coming from Centech >the EFI harness and back to the solenoid.

dang, so I am wrong to run that violet "start" wire down to Garry's tan/red, guess that wrecks my progress.

Enclosed is a break down of the Ign switch wiring. And charge light indicator

"Then I have all these lights and switches that require a hot in run wire to power them, should they all be fused? how many can I wire together without overloading the wire? I have the "choke", "Distributor" and "idle sol" wires that I won't be using because of fuel injection, are these usable for those said lights and switches???"

These wires are supplied power through the Centech harness, probably on the same fuse. You would need to do some testing (with test light) to find out which fuse, how big, and what else it powers. They could be used for other things, depending on what you find from the above testing.

This is where it would be nice to have a Centech wiring harness breakdown :-[

agreed, a diagram from centech could help a wiring novice like myself

 

[EFI Guy]

Efi harness--

Trans harness-
Reverse light swtich---Prpl/Or-hot in run---self explained!
Bl/Pnk-power out to reverse lights--run a wire back to the pigtail itself???

Nuetral Saftey switch-Pnk-hot in start from ign swtich--does this go to the centech Violet start wire?
Tan/Rd-start signal out to solenoid--goes to "S" terminal on solenoid?

All of these depend on where you had me run the wires.

Pink is the neutral safety switch in from the ignition switch. If your wires are under the dash hook this directly to the start terminal on the ignition switch.

Tan/red is neutral safety switch out. Connect it to the starter solenoid S terminal if it comes out near the fuse box. If it is under the dash connect it to whichever wire Centech runs out to the starter solenoid S terminal. I ASSume that is the purple wire from your description.

I don't know how the Centech harness is set up for reverse light wiring. But have heard mentions of a plug near the drivers side that can be tapped in to. I really need a Centech diagram to answer better.

Purple/ orange is the reverse light switch in. Needs to be hot in run, fuse it at 10 amps if Centech doesn't already.

Black/Pink is the reverse light switch out that powers the lights.

I ASSume you can tap in at the plug mentioned for both of those wires. But without a diagram I can't give the colors or tell you if it's already fused.



Engine Harness-

Prpl/wht--high idle switch--any idea how many amp switch this should be?This will be a simple toggle switch (not momentary)and will draw less than 1 amp.

Thick red wire--ignition swtich hot in run and start---where does this attach on the ignition? Ideally you want to connect it directly to the ignition switch, but be sure that the terminal you connect it to is hot in start as well as run. If you can't connect it directly to the switch then connect it to the wire labeled Coil + as close to the switch as you can.

Rd/grn---Brake light swtich(hot when pressed)---does this attach on the actual brake pedal switch?Yes, to the side that is hot when the brakes are pressed. The Explorer system needs to know when you are pushing the brake pedal for a couple of different reasons.

Grn/rd---Charge light----anyone find a light for this?The green/red that I provided under the dash can either be run to your charge light, or you can wire it to hot-in-run if you don't want to use the charge light. I do not provide a resistor (I've never used one myself) but it's certainly not a bad idea to use one. I'll attach a diagram below, but it can't be capped off because it's needed to excite the alternator, also you can NOT use an L.E.D. for this light. You can use an L.E.D. for all other lights if you wish. I like these...http://www.ebay.com/itm/141185251951?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

Check his store for matching lights in other colors.


Then I have all these lights and switches that require a hot in run wire to power them, should they all be fused? how many can I wire together without overloading the wire? I have the "choke", "Distributor" and "idle sol" wires that I won't be using because of fuel injection, are these usable for those said lights and switches???The switches and lights will draw very little power, probably less than 3 amps altogether.I can't say for sure if they are already fused or not without a Centech diagram. But I suspect you could use one of those if they are hot in run for all of the switches and lights.

One last question, the fuel injected motor I took out was from a 88 crown vic with a distributor. It had a MSD box, coil and wires. This motor uses the coil packs, is there no need for the ignition box? Just curious, I am very inexperienced with electrical and fuel injection. Nope, no need for the MSD box.

Alternator wiring:

 

[fummins97]

Garry thanks again for the help. For the trans wiring, you left all four wires about 6" long and put what looks to be those weather pack leads on them. I will run the wires up to where they need to be. Everything else seems to be answered. thanks

 

[fummins97]

Finally connecting the final wires. The two grey wires marked BK SW1 & BK SW2 are connected to the two wires coming from the trans for the reverse lights. I am still confused on the two purple wires from the Centech harness. They each exit the harness loom only a few inches from each other. As far as I can put together one of them is For the neutral safety switch to the TAN/RD wire on the neutral safety switch. Then I believe I have to get the other purple wire from the PINK trans connector to the "S" terminal on the starter solenoid, but how? It's been said a hundred times, but Centech needs a damn schematic, there's no need for both start wires if I'm reading Garry's directions correctly. I'll try to draw my own schematic, someone smarter then me please check my connections!?

 

[EFI Guy]

You have the pink and tan/red reversed, but it likely doesn't matter since it's just a simple switch.

I don't understand why you have 2 purple start wires unless they you want your NSS wired in to both. What I would do is test them with a test light to see if one or both of them are hot in start. If one is hot in start connect it to pink. If the other is not hot in start then it may be the NSS out to your solenoid. Verify with a meter, but if that is the case then connect it to tan/red.

 

[fummins97]

okay so does one still have to be connected to the "s" post on the solenoid?

On an unrelated question, what wire goes to the small post on the starter itself?

 

[EFI Guy]

Yes, the NSS out needs to go to the S terminal. My thinking with 2 purples is that perhaps both go to your NSS and you have a wire coming out near your solenoid also that goes to your S terminal? I really need a diagram or detailed instructions for that harness to be sure. But at the end of the day Tan/red needs to power your S terminal, whether it goes through the Centech harness or not is the question.

You will need to modify the starter wiring like this diagram.

 

[904Bronco]

Yes, the NSS out needs to go to the S terminal. My thinking with 2 purples is that perhaps both go to your NSS and you have a wire coming out near your solenoid also that goes to your S terminal? I really need a diagram or detailed instructions for that harness to be sure. But at the end of the day Tan/red needs to power your S terminal, whether it goes through the Centech harness or not is the question.

You will need to modify the starter wiring like this diagram.

View attachment 401344

It will look like this:

 

[fummins97]

So 904bronco here's what I have, tried to draw it out easy to read and easy to understand if I made a mistake. The purple "start" wire I'm using comes out of the Centech harness with the batt, alt, "I" term and reg s wires. The other purple wire is in a 3 pack plug with coil+ and ign power wires. Hoping I can just use the first purple and seal off the plug. Still unclear where the small post on the starter wire comes from. I have a smaller gauge wire on the heavy gauge wire that goes from the starter solenoid to the starter heavy post? I'll include it in my pictures below. Sorry for the questions, just want to wrap this up!

 

[fummins97]

Sorry for the mess

 

[fummins97]

Also my alt digital gauge is always on, wired it like the diagram said from the positive side post of the starter solenoid.

 

[Viperwolf1]

Also my alt digital gauge is always on, wired it like the diagram said from the positive side post of the starter solenoid.

Connect it to the ACC terminal at the rear of the ignition switch instead of the starter solenoid. That way it will come on when the key is in RUN or ACC.

 

[ryan97]

Just installed a Centech in my 73 with carb set-up so can't help you there, but what I would say is call Centech, the guys were very helpful with my questions and depending on your set-up not all wires may be used.

 

[DirtDonk]

I'll weigh in on this fummins. You might not need either one depending on if Garry's Pink wires are stand-alone or not. I'd go back and re-read that first post he made with the detailed answers. Ok, so I will too when I'm more awake, but for now, I'll list what the Centech wires do at least and why there are two.

Centech includes two separate Purple/Violet wires that have the same function. You use only one of them, depending on which transmission type you run.

The short one for manual transmissions only. It is directly from the key and simply attaches to the starter relay's "S" post and you're done.

The long one is for an automatic with a neutral safety switch. It's a duplicate of the short one, but is long enough to run first to an NSS and then back out to your starter relay.

That's it. Simple sort of, but not sure really why they bothered with two wires to confuse the masses, when one long one would have done the trick.
Maybe there's a really good reason I'm not thinking of right now, and when I was installing my last one on a '73 I really didn't think much about it.
But there 'ya go.

The one you don't use gets cut off. Or you could use it for your "START" signal for an EFI computer if you didn't want to add more wires to your starter relay.

Paul