Electrical issues

[Fixnstuff]

Mine melted at the power to the glow plug controller.So I ran a direct line from controller to the fender mounted solenoid. I removed the two yellow feed lines that are the way ford engineers ran power to the controller. Two lines are cheaper than one large line in the electrical industry. I used 6 gauge speaker wire purchased from an car stereo shop with heavy lugs to fit both ends.

As far as current carrying capacity you will probably get by, it may be more than you need, over kill BUT: Speaker wire is the WRONG wire to use because speaker wire uses very small strands and a larger number of strands and that is FOR THE PURPOSE OF IMPEDANCE in Speaker Circuits. I'm not an expert, I've not been employed in the electrical or electronics profession but I've been through electricians school with straight a grades and have a good understanding of the science. What I just mentioned is something that I read when I was researching the wire used in Fusible Links. That is very high purity low oxygen copper so they will all melt through at the same temperature. I learned a bit about stranded wires in the process.

Secondly the insulation on speaker wires is NOT suitable for being close to an engine in an engine compartment and subject to oils, fuels, solvents and potentially quite high temperatures.

You might get by for awhile or a long time on those counts but I would say that the insulation is going to be affected and get brittle from engine heat and along with the presence of oil, fuel and solvent fumes probably deteriorate before it would with proper wire insulation specs.

LASTLY, if you did not include fusible link or CIRCUIT BREAKER in that wire YOU could have A VERY BIG AND DANGEROUS PROBLEM in the future. If that "always hot" wire ever shorts to ground with no circuit breaker or fusible links you are likely to have a dangerous and at le4ast very damaging engine fire and likely and maybe an exploding battery or two unless the starter relay explodes into a cloud of flames and smoke first, cutting off the voltage from the batteries.
Without conforming it by looking at the circuit again I am quite sure that is what would happen.

What WOULD DO, for both of you guys who mantoned using a single Power Cable to the Glow Plug Relay, IS, INSTALL A MANUAL RESET CIRCUIT BREAKER.

I looked into this while researching how I could best repair my harness or build a new harness and the reason that I would select a MANUAL RESET circuit breaker is because an automatic reset breaker will keep resetting itself as it cools down, closing the circuit again (allowing current to flow to the dead short) each time. It will likely break the circuit immediately each time but with a Manual Reset you will have to open the hood to reset it and AT THAT TIME, you can examine the wiring to try to figure out what is causing the breaker to trip. Normally it would have to be a short somewhere along that single cable. OTHERWISE it could be a failing circuit breaker.

I really don't know without some more study of the circuit, what rating that circuit breaker needs to be. YOU DON'T want it to be too high or too low. I know it wuill be at least 50 Amps, based on the approximate rating of the original fusible links but doubling that to 100 Amps may be TOO HIGH.

Remember that the solid state controller has a LARGE Ribbon or "Z-bar" resistor on top of it which drops the voltage from 12 volts on the power side of the Glow Plug Controller Relay, down to 6 Volts that actually goes to the Glow Plugs. I THINK that resister thus lowers the current demand in the power wires that go to the Glow Plug Relay from the battery VIA the starter solenoid. It's certainly not 200 Amps as some people have suggested in old topics or those fusible links would instantly melt.

Anyway, I am too brain-fogged from pain pills to analyse this any further. (lost my concentration) that's why my posts tend to be so long. My memory is also affected so, I just HOPE that I have everything right so far.

The most important thing that I see is for those single power cable users is to INSTALL A CIRCUIT BREAKER.
I just don't know what the correct rating would be for a single cable. Someone who works with electronics circuits can probably figure it out based on the fact the the TWO power wires each have a 14 GA Fusible Link

There might be a style of circuit breaker better than a manual reset breaker, it's been a long time since I studied all of this and there are several types of circuit breakers that could be used.

 

[Fixnstuff]

I have this to address also, but I seem to have a problem a bit different that whet most seem to have....

My plug seems to still be in decent shape:

My issue is the insulation is missing from the wire, not the plug:

I AGREE. Someone cut too much insulation from those wires and it's possible that was a replacement plug from back when they were still available.

To save yourself a lot of extra time, work and frustration, I WOULD RE-USE THAT PLUG but BYPASS the two power wires as there surely would be a problem with those in the future.

Depending upon how old that plug is, they get stiff, inflexible and somewhat brittle after many years, it may be DIFFICULT to pull apart, eg: STUCK and it's likely to be STUCK at the pin connectors for the 2 power wires. I'll show you how to deal with that. You can simply CUT AWAY the nylon around those pins and just remove that 'power wires' end of the plug so now you'll have a 6 terminal plug. Then just cut the excess bare wire strands from the yellow wires and butt-splice them to the Black/Brown wires. That is what I have in my truck now. I'll post a photo a little while within THIS post to show you how to do it and what is INSIDE of these connectors.

Otherwise to install a NEW plug for all of those small wires you are going to have to cut off all of the factory male and female pins on 13 wire ends and crimp on a new style of male & female pins on 13 wire ends and then reinsert all of those into a NEW style of plug connector. Without specialized professional crimping tools you won't be able to match the quality of the crimp to the original pins from the factory. I wouldn't do that unless your intent is to build a whole new harness, like if you are intending to make it a custom show truck or something or you want to do a complete full restoration on to say "This whole harness is ALL BRAND NEW."

That plug looks GOOD except for the cracks over the Black/Brown power wires. It may be cracked because someone tried to remove the pins. I've done precisely that myself so I'll show you how to get those out and just remove those two terminal spaces from the whole nylon plug and then you will have an intact factory 6 pin plug instead of an 8 pin.

The reason I did this work is that my glow plug RELAY FAILED in the STUCK CLOSED position providing CONSTANT FULL VOLTAGE & CURRENT from the batteries to the controller and glow plugs for about 15 minutes straight, My new batteries were completely drained as I was driving it and then again for about another 10 minutes before I could finally get it home.

Things got VERY HOT back at the GP Controller, the heat from the ribbon resistor melted through the controller cover, the Relay was burnt pretty bad and the failure causing constant voltage to the glow plugs for so long, toasted one glow plug connector which was a replacement bullet connector that I had installed, (It actually melted due to a bad connection) BUT IN SPITE OF ALL OF THAT, The controller protected everything, all of the glow plugs, including the harness wires and fusible links and that controller IS PROBABLY STILL GOOD!

I took that opportunity to REPLACE all of the following: GP Controller, Voltage Regulator, Alternator (upgrade from 70 amp to 90 amp), New factory made Positive Battery Cable Assembly, fix the harness, some of the connectors and ring terminals, and maybe a few other things I've forgotten but I can help you with some tips along the way to getting yours fixed.

I'll reply to other things in your post later.

 

[DrCharles]

The number of strands and their gauge has absolutely no effect at DC, which our glow plugs run on. Skin effect is barely measurable even at the highest audible frequency (20 KHz). Again, that's completely irrelevant at DC (0 Hz). The only important factor is the total equivalent gauge of all the strands! And check out the late Bob Pease's blind tests with expensive speaker wire vs. lamp cord. No one could tell the difference better than a coin flip.

Now, in an automotive environment, more smaller strands is sometimes better because it increases flexibility and resists strand breakage. Sometimes that's NOT desirable (such as a battery cable) because you don't want it moving around and wearing through the insulation. This happens not only from vibration and engine movement, but at the high currents during cold cranking the force on a cable due to magnetic field can be surprising.

The OEM's designed things for a reason, and cost is always one of those considerations. I agree that finding a connector with two high-current and multiple low-current contacts will be difficult and not worth it. I like the approach of using good barrel connectors and crimp tools, and on the rare occasions when you might need to disconnect them, just cut them!

BTW I do have an EE degree

 

[Joseph Davis]

I got rid of the old yellow wires to glow plug controller because old wire creates heat because it breaks down over time. new wires and no problems for my truck. starts like a charm on cold mornings. Good Luck

 

[Fixnstuff]

The number of strands and their gauge has absolutely no effect at DC, which our glow plugs run on. Skin effect is barely measurable even at the highest audible frequency (20 KHz). Again, that's completely irrelevant at DC (0 Hz). The only important factor is the total equivalent gauge of all the strands! And check out the late Bob Pease's blind tests with expensive speaker wire vs. lamp cord. No one could tell the difference better than a coin flip.

THANKS MUCH for the correction and clarification. I was hoping someone 'in the know' might reply to that comment. Yes it was "Skin Effect" that I had read about when researching what kind of wire to use for glow plug wires when building an all new harness but it was only specifically about multi-strand wire specifications and it didn't indicate AC or DC current applications. I was also figuring out the difference between regular wire and fuse link wire (a difference that I have already mentioned)

BTW There was a write up at FTE or here at OB by someone who made a NEW harness and he stated the he used "Resistance Wire" in accordance with the specs printed on the glow plug wires insulation - - others suggested that meant "Fuse Link Wire." If you recall reading that topic do you have an opinion on what he meant by "Resistance Wire" or if in fact the glow plug wires are the same as Fuse Link Wire?

I have read that Bob Pease article before. I have a home recording studio with very expensive KEF studio monitors (speakers) an obsession that I abandoned some years ago so that's when I read about it.

THANKS for taking the time to write all of that interesting information. I'm going to skip down to your last line:

I like the approach of using good barrel connectors and crimp tools, and on the rare occasions when you might need to disconnect them, just cut them!

BTW I do have an EE degree

OK BUT, it appears that you have a manual transmission. I have an automatic and when working on the truck I occasionally have to shift it OUT of PARK to NEUTRAL. ie: so I can free the drive train to turn freely, or certain wiring that is only on when the ignition switch is "ON" In order to do that the key has to be turned to the "RUN" position to unlock the steering column. The glow plugs are being energized and I CAN'T turn the key to "OFF" unless the shift lever is put back in PARK which again Locks the steering column and the drive train, and de-energising wiring that I might need to test. Cutting and re-splicing the glow plug wires every time isn't gonna be fun.

The best solution in this case is disconnect plugs for the 2 GP power wires. Otherwise I have to disconnect the batteries every time I need to put the truck in Neutral. The connectors would also allow me to power up the electrical components associated with the "ON" aka "RUN" position of the ignition switch. Right now the 'ACCESSORIES' position doesn't work (no power to accessories) - something I will have to fix one of these days but I have other priority work to get done on the truck.

THANKS AGAIN for your informative post!

 

[nelstomlinson]

I agree with DrCharles, skin effect isn't really an issue for DC. At just 60Hz, the skin effect for copper is around 3/8" as I recall, and the conductive layer gets deeper as the frequency goes down to DC. For things like glow plugs and starters, bigger really is better!

Fixnstuff is absolutely right about the importance of overcurrent protection like fuses or fusible links, and absolutely right about having the right kind of insulation that can stand up to conditions in the engine compartment.

 

[My 90 oil burner]

I have to replace the Glow Plug wiring and connectors. I bought the connector kit on ebay and have purchased 10 gauge wire for the main part of the harness. There are little silver connectors on there that I cannot find nor know the actual name of them to get the correct part. ANY IDEAS?

 

[My 90 oil burner]

Well after getting all new engine sensors and the GPR we have the complete harness on the table and will be replacing the 2 yellow wires and the 2 brown w orange stripe wires with 1 6 gauge wire each with inline fuse. Also will be repairing any breaks in the wiring as well as replacing the headlight and turn signal connectors along with a few pigtails for sensors. Hopefully this will be done this weekend but not 100% sure yet.
I also bought new voltage regulator and starter solenoid so hopefulley all the electrical will be better than new when I finally get to fire the ol pig up.

 

[Fixnstuff]

I have to replace the Glow Plug wiring and connectors. I bought the connector kit on ebay and have purchased 10 gauge wire for the main part of the harness. There are little silver connectors on there that I cannot find nor know the actual name of them to get the correct part. ANY IDEAS?

I don't understand where those 'little silver connectors' are. I've not seen anything like that on the two harnesses I worked on. Even if you did replace them, exactly where are they?

 

[My 90 oil burner]

I don't understand where those 'little silver connectors' are. I've not seen anything like that on the two harnesses I worked on. Even if you did replace them, exactly where are they?

They are just little connectors the GP wire are spliced into. I am not using them I bought tees like the 6.0 has to make my jumpers to the GPs

 

[chris142]

i just spliced around the connector. works fine now

x2

 

[retiredinhomer]

x2

I used split bolt connectors then insulated tape. easy to disconnect.

 

[Fixnstuff]

I used split bolt connectors then insulated tape. easy to disconnect.

WOW, that is an excellent idea! Except for having to use a LOT of electrical tape over the shape of a standard split-bolt connector. There is also a style in a rectangular block shape that uses recessed Allen screws but I could only find these for 6+ gauge wire (power distribution systems for buildings)

Sorry this post is so long, I am trying to cover a LOT of details, in detail that others may encounter.

I want something easier and quicker to disconnect and reconnect as I'll have to disconnect power to the GP Controller Relay more often than most people will. IE: To shift from Park to Neutral (Automatic transmission) I have to have the key in the "RUN" position to unlock the steering column AND to unlock the drive train and sometimes I STILL need power to the rest of the circuits from the batteries so the only viable solution for me is a quick disconnect in the power wires to the GP relay.

I am considering your method IF I can find or make it myself, a clip-to-close insulation cover to clip on over the connectors, something like the plastic piece that clips together over the 3-way junction of the wiring harness located behind the glow plug controller. That way I could use just a couple of short strips of tape to make sure it doesn't un-clip and come open.

Rather than doing that I think I have made a decision about what I am going to use as ONE connector for both wires. It's insulated, probably oil resistant, not sure about heat resistance, probably is and actually I won't need much heat resistance at all due to the location it will be in.

This single connector for 2 separate wire runs rated at 75 AMPS, more than enough. Once I solder the internal connectors to the wire ends and insert them into each side of the plastic connector I can simply pull it apart and reconnect it whenever I want.

It's called:
Battery Quick Connect Disconnect Electrical Plug 6-10 Gauge 75 Amps for Recovery Winch or ATV Quad https://www.amazon.com/Battery-Connect-Disconnect-Electrical-Recovery/dp/B00FXWLD88

I considered this connector a long time ago but I thought at the time, "It's too big and ugly, I want one a lot smaller" Unfortunately, I could not find a single wire connector rated for 50 amps or more that was small, nor one for two separate wire runs. I only recall (if I remember correctly) seeing connectors with that high of rating that were also circuit breakers, they were not small and I would need two of them.

I just went out and checked the harness on my truck. For the convenience of it's function this one is NOT too big. When connected it measures 1/2 in. thick (12.7mm) 1-3/8 in. wide (<34.9mm) and 3-3/16 in. long (<81mm).

I will remove the rubber cap on the engine side and keep the one on the battery side because those connectors are always hot even though they are recessed into the plug.

My existing main harness connector and the butt-splice connectors for the GP power wires are far away from from the valve cover and exhaust manifold, more than half-way across the top of the fender well toward the edge of the fender. PLENTY OF ROOM THERE and far away from manifold heat or any oil or fuel that might someday leak.

I'll probably install this new connector at the same location where the crimp on butt-splices are now, slightly to the engine side of the main harness connector, OR I may trim back the wires on the engine side so the new connector is not next to the main harness connector, so as not to disturb the main harness connector whenever I have to disconnect reconnect the new plug.

BY THE WAY: Originally my main harness connector was hanging over the edge of the engine side of the wheel well and the harness going over the valve cover was hanging down quite close to the exhaust manifold. The main connector is now where I stated, far away from the engine and the harness wiring is far away from the exhaust manifold.

The difference was in all of the slack that I had in the Battery Side of harness before I made the repairs. Somehow it had slipped toward the engine and that's where it wanted to stay!

When I reinstalled the repaired harness I also removed and replaced with new, all of the old split black plastic 'conduits' and replaced the old electrical tape that held the wires together. It just happened without planning that the previous slack was taken up and I now have nearly a full loop of extra harness wire on the battery side closer to the fender, well behind the starter relay it doesn't interfere with anything and it wants to say right where it is.

The harness from the main connector to above the valve cover is in almost a straight line and far away from manifold heat but there is virtually no tension on it. If engine movement was to require more slack it can pull at least another 5-6 inches from the loop with virtually no resistance = not a problem at all.

I mentioned this to let you know that if your harness is hanging down close to the exhaust manifold the extra slack can be easily taken up on the battery side. You may have to remove the old plastic conduits from the wires and reinstall or replace those (re-tape the wires inside may be a good idea too) to pull up the slack so it will stay in place without a wire tie. You'll be reshaping the wire loom when you do this. For me it happened by chance, not by plan. Or, you can just use a wire tie somewhere but I didn't see a convenient place to tie it before or after the repair and I won't need to tie it now.

Thanks for that split-bolt wire connector suggestion. It's a very good one, but I'm probably going to do it with that big ugly red battery disconnect. ALL RED, at least everyone should KNOW that it's a HOT wire connection and the contacts are recessed into each side of the connector.

 

[Fixnstuff]

Holy BUNK I nearly wrote a whole chapter in a book with that post. SORRY! I may come back later and delete half of it! Or more! Can't do it now though!

 

[Fixnstuff]

I used split bolt connectors then insulated tape. easy to disconnect.

Wait a minute! I thought you meant regular THIN electricians tape.

Are you talking about something else that is a thicker insulation tape? What is it?

Oh yeah, I Just thought about this! With that method the battery terminals have to be disconnected or we will have TWO VERY HOT WIRE ENDS EXPOSED. Eeeks! I can't do it that way for my purposes. I hope that no one in the future takes those connections apart not realizing that two ends are ALWAYS HOT, directly from the battery. There are fuse links on that side, I forgot, so it is safer but an added nuisance to replace fuse links and have yet more splices in the wiring.

SORRY FOR THAT LONG POST but I can't get back to it to for awhile tonight to change it.