Looking for wiring diagram for a 81' Ford 4100 Diesel

[Other Bob]

As the title says I'm looking for a wiring diagram for the 4100 Ford diesel. I have the I&T manual which has a diagram for the gas but doesn't have the additional details for the diesel.

Previous owner did some rewiring and replaced ignition switch with gas version that doesn't have heat features. Trying to figure out how to get that functional again. Also it appears that their is an intake restriction switch on the air cleaner pipe that I'm also trying to figure out if it is wired correctly. At least I think it's a restriction switch, I can't find any mention of it in the manual and no pictures online.

 

[Agvg]

It's easy to replace it ignition switch with the right type, suppose it has a flamestart in the manifold?

 

[HakanTh]

I have a 10-series shop manual, partly, it covers 4100 as well. It has been copied and organized in an odd way in a pdf. I selected some pages which I think you may have use for. The wiring differs a bit, depending on where the tractor was assembled, if it has a cab and what type of cab it is.

The diagram is for a "C" prefixed tractor (assembled in US) without straddle mount cab.

I also attached pictures of the two different key switches that were at hand for this model. As far as I can see on the other wiring diagrams, the wiring is the same for both of them. At least the Thermostart wire is Brown/Red and attached to lug #3 on all of them.

The air cleaner warning, #24 and #11, have a straight forward wiring in the attached diagram. The manual has diagrams showing other solutions, and I am not certain of what might be the right diagram for you.

Hope it helps.

 

[Other Bob]

Thank you guys for the responses.

I did verify that it has the thermostart. Now I just have to get a new switch with heat setting and work though the electrical diagrams (HakanTh thanks for those). I know that when I looked at the tractor the gauges were working and between then and when it got delivered there was an incident and some of the wiring melted. The made a wiring repair and installed the wrong switch. The only thing working on the gauge cluster now is the tachnometer. I can see lots of new wiring but I'll have to do some reading to learn how to troubleshoot and fix.

 

[Other Bob]

So looking for some more help.

Started poking around with the wiring, although it has the thermostart on the manifold there are no wires going to it, looks like it's missing from the front half of the wiring harness. Additionally I had watched a video about fixing gauges and his fix was pretty simple just a blown fuse that fed the cluster. However I pulled my cluster and don't see any fuse. Also my cluster doesn't have a voltage stabilizer. I did some searching and found a thread that said that the later clusters didn't have a voltage stabilizer. They claimed that there was a cluster change that changed the tachomoter to go from left to right and when they made that change they also eliminated the stabilizer. The wiring diagram HakenTH privided shows both a fuse and voltage stabalizer so I'm not sure if it's missing or due to changes. Also the warning lights don't come on which I don't think would be related to a missing stabilizer.

I figured I can run a wire for the thermostart easy enough, and I'm thinking I should add an inline fuse for the cluster as well.

Does anyone know if there really was a cluster change that didn't require the stabilizer? What gauge of wire should I run for the thermostart and what amp fuse?

 

[HakanTh]

One thing to have in mind when you are looking for parts and information regarding 4100 is that there are two different Ford 4100s. Make sure that it is the right period of manufacturing. Take a look at New Holland's parts catalog:
Official New Holland Online Parts Store and Online Parts Catalog for New Holland and Ford Tractors.

Official New Holland Online Parts Store and Online Parts Catalog for New Holland and Ford Tractors.

The series before your 4100 was the 1000 series (6X and 6Y, 1/65-12/74), that included the model 4000. The all purpose agricultural derivative from 4000 was 4100, but badged "4000", and normally you just say "4000", no matter what derivative it is.

Your 4100 belongs to the 600-series (1/75-12/81). It is a bit confusing, but Ford developed the old 4000 to 4600, so that number was taken. 4100 from the 600 series is a developed 1000 series 3055, so it would have been natural to name it 3655...



The tachometer was driven by the generator on the 1000 series, and the tachometer needle was moving clockwise. The 600 series 4100 had an alternator, the tachometer was driven by the oil pump shaft, and the needle moved counter-clockwise.
*** Edit:
It seems that the tachometer was clockwise up to 31/3 1976. This one:
Case IH / New Holland: CLUSTER, Part # EHPN1849AGV
***



According to NH parts catalog, it seems that the voltage stabilizer, as a part, was no longer needed for tractors assembled after 31/5 1979. Probably, the stabilizer is internal after that and it is of a solid state type. There are information on some pages of my manual "bundle" that says it is printed in 1977. There is no dating on the wiring pages I showed, most likely they are not up to date with your 1981 wiring, sorry...



I am not sure about the wire for the Thermostart, but I think it is 9 to 11 AWG. Measure the current, then you can find out suitable sizes for wire and fuse. I put a relay on my 4000 for the Thermostart, I want to keep the currents through the key switch as low as possible, there is not much material in there.

 

[Other Bob]

....
I am not sure about the wire for the Thermostart, but I think it is 9 to 11 AWG. Measure the current, then you can find out suitable sizes for wire and fuse. I put a relay on my 4000 for the Thermostart, I want to keep the currents through the key switch as low as possible, there is not much material in there.

Thanks for the information. So if I'm understanding you correctly you have a 9 to 11 AWG wire from the battery to relay to thermostart, and a smaller 14 or 18 AWG from switch to control side of relay?

 

[HakanTh]

Thanks for the information. So if I'm understanding you correctly you have a 9 to 11 AWG wire from the battery to relay to thermostart, and a smaller 14 or 18 AWG from switch to control side of relay?

Yes, one like this is convenient, compact and practical:
Mini Make & Break Relay 12V 30A With Blade Fuse | 12 Volt Planet

I have overworked the wiring, I am a relay fetishist, but when it comes to the Thermostart it is not only the fire hazard that made me use a relay. It is good to have as much current as possible to make the glowing start.

 

[RickB]

Thanks for the information. So if I'm understanding you correctly you have a 9 to 11 AWG wire from the battery to relay to thermostart, and a smaller 14 or 18 AWG from switch to control side of relay?

There is no relay, the key directly controls thermostart. The voltage stabilizer was eliminated mid production of the x600 series concurrent with a resistance change in the fuel and temperature gauge/sender pairs. The instrument clusters and sending units must be paired correctly according to the tractor’s build date or unit code.

 

[Other Bob]

He wasn't saying there is a relay standard, just that he wired his up with a relay. Since I have to run new wiring for the thermostart that's what I'm planning on doing as well. I'm running 16 gauge wire fromt the switch to the relay. Then 10 gauge from the battery through the relay to the thermostart. Planning on using a 35 amp fuse in that wire because it's the largest I have on hand.

Also since gauges weren't working I pulled the rear part of the harness and gauge cluster out to investigate. After cutting of the plastic loom I found the old inline fuse inside the loom. I'm assuming it's blown and I couldn't fnd a replacement fuse locally so I'm going to replace it with an inline spade fuse. There were also some bare wires in there where it looks like it got rubbed off on the gass tank seam. I put liquid tape over the spots, hoping that workds. Also the fuse on the light switch was blown so I replaced it. Planning on finishing it up today and testing.