ddalder 5 #1 Posted June 21, 2016 Hi All! I'm trying to resurrect a 1976 C-120 for a friend that experienced a rather significant electrical meltdown. Much of the wiring got really hot and burned. I'm not entirely sure yet what caused this but I did notice the potting material used to encapsulate the regulator/rectifier has a large crack in it. From past experience, this potting material is very robust which leads me to believe that something inside got rather hot. In addition, There are numerous base connections evidenced by melted connector housings on the regulator and ignition switch. I contacted Toro and was a little surprised because they were not able to located a schematic for this tractor. I've seen a few on the forum here that appear to be close (if not the same) as this model tractor but aren't labeled as such. I'm wondering if someone can point me in the direction of one. I didn't see anything in the manuals section of the forum that was quite this old. Electrical doesn't scare me. I have many years experience in modifying and/or building custom wiring harnesses for automotive applications including a wide array of tools. What I'd really like to find are replacement connector housings and terminals for at least the ignition switch and regulator, I'm waiting for a parts manual that Toro is sending but I have no idea if the catalog is broken down to this detail, or if these items are still available. Can anyone tell me also whether the regulator is available or what options I have? I appreciate any help that is offered Thanks! Share this post Link to post Share on other sites
rmaynard 15,754 #2 Posted June 21, 2016 Get the ID from the tag above the height adjuster on the left side of the hood stand. If it's a 1976, the number should read 61-12K801, 802, 803, or 804. With that number, we should be able to find the correct wiring diagram. And yes, the regulator is still available from many sources. It should cost around $35 to $45 U.S. 2 Share this post Link to post Share on other sites
ddalder 5 #3 Posted June 21, 2016 That's great news! Thanks. The Tag reads 61-12K801-02961. I'm assuming that the 02961 is the serial number portion of the tag. Share this post Link to post Share on other sites
ddalder 5 #5 Posted June 21, 2016 Fantastic! Thanks much everyone. I'm going to try and source that regulator. Hopefully I'll be able to find the connector bodies/terminals as well. If not I have some other thoughts on how I can wire those. Share this post Link to post Share on other sites
KC9KAS 4,741 #6 Posted June 21, 2016 @ddalder I completely rewired a C-160 a couple of years ago. I bought the correct colors of wire, 1, 2, 3, 4 & 5 position plastic connectors with the associated male/female terminals, as well as the crimping tool. The tool cost as much as everything else, but it sure did make a nice new wiring harness! 1 Share this post Link to post Share on other sites
squonk 41,739 #7 Posted June 22, 2016 If the regulator terminals are arranged with 2 side by side and the 3rd directly between the 2 either above or below them, then a std. pre-mid 70's headlight dimmer ( floor mounted) connector from any car is the same. Your local Napa can get this 1 Share this post Link to post Share on other sites
ddalder 5 #8 Posted June 22, 2016 (edited) 1 hour ago, KC9KAS said: @ddalder I completely rewired a C-160 a couple of years ago. I bought the correct colors of wire, 1, 2, 3, 4 & 5 position plastic connectors with the associated male/female terminals, as well as the crimping tool. The tool cost as much as everything else, but it sure did make a nice new wiring harness! Crimp tools are very expensive. I have a number of them for both generic applications and some that are very specific to certain Delphi terminals. Looking at what's there, I believe my generic crimp tools will work perfectly. Can I ask where you bought the connector housings and terminals? 1 hour ago, squonk said: If the regulator terminals are arranged with 2 side by side and the 3rd directly between the 2 either above or below them, then a std. pre-mid 70's headlight dimmer ( floor mounted) connector from any car is the same. Your local Napa can get this Unfortunately, it's not. And here are 'some' pics of the burnt wiring... Edited June 22, 2016 by ddalder Photo Links. Share this post Link to post Share on other sites
KC9KAS 4,741 #10 Posted June 22, 2016 8 hours ago, ddalder said: Can I ask where you bought the connector housings and terminals? I knew you were going to ask this...Right now I don't remember, but I will check the parts and try to find out. Seems like the brand name had something to do with Chevys....I'll check it out..... Share this post Link to post Share on other sites
Southerncannuck 73 #12 Posted June 22, 2016 (edited) I just rewired my C125. I simply used individual spade connectors instead of the original connector housings Edited June 22, 2016 by Southerncannuck Added picture 1 Share this post Link to post Share on other sites
ddalder 5 #13 Posted June 22, 2016 7 hours ago, KC9KAS said: I knew you were going to ask this...Right now I don't remember, but I will check the parts and try to find out. Seems like the brand name had something to do with Chevys....I'll check it out..... This is certainly a possibility as well. I had considered this but thought I'd try and source the connector first. If I can't get the necessary parts, this is likely what I'm going to do. 6 hours ago, squonk said: Packard. It does look very much like a Delphi/Packard 56 Series connector. I'm going to order a couple and I'll post back about findings. If it's the one I think it is, they are readily available and very inexpensive and I already have the terminals in my P.E.D. terminal service kit. Share this post Link to post Share on other sites
KC9KAS 4,741 #14 Posted June 22, 2016 5 hours ago, ddalder said: It does look very much like a Delphi/Packard 56 Series connector. I'm going to order a couple and I'll post back about findings. If it's the one I think it is, they are readily available and very inexpensive and I already have the terminals in my P.E.D. terminal service kit. Yes, DELPHI 56 SERIES. I got mine from TheElectricalDepot.com The part # for the 5 position ignition switch is 2973422. I also got the crimper from Del City and it is part # 990168. 1 Share this post Link to post Share on other sites
ddalder 5 #15 Posted June 22, 2016 (edited) Very nice! Thanks for posting this. I ordered the connectors and terminals through www.mouser.com because they will ship overnight air to Canada for $20, including brokerage. The Delphi part numbers I ordered are: 02973422 - Connector, 5-Way 56 Series Female BLK 02977048 - Connector, 4-Way 56 Series Female BLK 12124517 - Terminal, Tin-Plated Female 2.00-1.00mm2 Core, 2.48-3.05mm Cable Diameter Looking at the Delphi specs, I'm not sure what the difference is between the terminal you used and the ones I ordered. I could dig into the technical drawings and figure it out but it really won't make any difference. I do have the correct crimp tool for these. I've got many, many rolls of high temp harness tape (different than electrical tape) I'll finish the project off with. I quite like Mouser Electronics because they will sell singles of most items, they ship the same day (if in stock) and their prices are very reasonable. I've used them for numerous items over the years. BTW, Toro quoted me $149.39USD for a regulator/rectifier and they weren't sure if they could ship to Canada. A local Toro dealer quoted me $286.60CAN but it had to come from Toronto. The same dealer did some digging and told me that they stock one made by Stens (P/N 435-024) that is a replacement. They had this one in stock for $103.60CAN. It does have what appears to be the same 3 terminal configuration as the existing part. Edited June 22, 2016 by ddalder Share this post Link to post Share on other sites
KC9KAS 4,741 #16 Posted June 22, 2016 7 minutes ago, ddalder said: Very nice! Thanks for posting this. I ordered the connectors and terminals through www.mouser.com because they will ship overnight air to Canada for $20, including brokerage. The Delphi part numbers I ordered are: 02973422 - Connector, 5-Way 56 Series Female BLK 02977048 - Connector, 4-Way 56 Series Female BLK 12124517 - Terminal, Tin-Plated Female 2.00-1.00mm2 Core, 2.48-3.05mm Cable Diameter Looking at the Delphi specs, I'm not sure what the difference is between the terminal you used and the ones I ordered. I could dig into the technical drawings and figure it out but it really won't make any difference. I do have the correct crimp tool for these. I've got many, many rolls of high temp harness tape (different than electrical tape) I'll finish the project off with. I quite like Mouser Electronics because they will sell singles of most items, they ship the same day (if in stock) and their prices are very reasonable. I've used them for numerous items over the years. Glad you found and ordered the parts. I was very happy with the results of my C-160 wiring harness build. By the way, my C-160 threw the rod last winter, but I don't think the wires had anything to do with that....Lack of oil maybe, but not he wiring! Share this post Link to post Share on other sites
ddalder 5 #17 Posted June 22, 2016 3 minutes ago, KC9KAS said: By the way, my C-160 threw the rod last winter, but I don't think the wires had anything to do with that....Lack of oil maybe, but not he wiring! Ouch! That's very unfortunate 1 Share this post Link to post Share on other sites
wrightorchid 261 #18 Posted June 23, 2016 I tend to use the heat shrink sealing connectors, that are covered, and then use sealed fuses. Better for wetter conditions and reliability. Share this post Link to post Share on other sites
ddalder 5 #19 Posted June 27, 2016 (edited) I got to work on rebuilding the wiring today and everything went very well. There are definitely some differences between the schematic for the 1977 and this tractor, however nothing that created a big problem. Basically the main difference is a connector attached to a safety interlock switch triggered by the PTO lever. The seat safety switch also connects into this. There's a total of six wires at the connector but there is nothing like this shown in the wiring diagram. Someone had definitely made some rather questionable repairs in the past. Since this isn't my tractor I really have no idea what the history is. My friend questioned a few things as well which led me to believe he didn't know what had previously been repaired either. Here are a few pics of the old wiring removed from the tractor... This is the start of the new wiring harness. "Blue wire???" you might ask??? Yes, that's right! There seems to be some sort of wire conspiracy in Canada right now. I went to a couple of industrial suppliers along with a few different auto parts stores and no one had 14AWG orange wire. It wasn't just that they were out of stock, they didn't carry it at all! These are a few more shots of the new wiring. I wrapped it with wiring harness tape intended for engine compartment use in the automotive industry. Much of the harness was also enclosed in split loom, wherever there is a risk of chafing. With the exception of the Series 56 terminals, I crimped, soldered and applied adhesive lined heat shrink tubing all other terminals. Since none of the components or connectors are sealed, the adhesive lined heat shrink tubing was overkill but definitely not a bad thing to do. So here it is... The 1976 C-120 Wheel Horse rides again! With a new regulator/rectifier and wiring, everything works great. Thanks to everyone who chimed in to offer assistance! The help was most certainly appreciated Edited June 27, 2016 by ddalder Photo Links Disappeared. 3 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,152 #20 Posted June 27, 2016 I think the wiring diagram earlier in this thread is from the 1977 manual since we don't have one for 1976. I am wondering if the 1975 wiring is a closer match to the 1976 Garry 1 Share this post Link to post Share on other sites
ddalder 5 #21 Posted June 27, 2016 3 hours ago, gwest_ca said: I think the wiring diagram earlier in this thread is from the 1977 manual since we don't have one for 1976. I am wondering if the 1975 wiring is a closer match to the 1976 Garry That's exactly it! Diagram for the 1975 matches perfectly. Thanks 1 Share this post Link to post Share on other sites
Thatoneguy 197 #22 Posted July 10, 2016 I have a Owners Manual and Parts Manual for the C-120 automatic. If anyone needs one. 1976 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,152 #23 Posted July 11, 2016 23 hours ago, mower said: I have a Owners Manual and Parts Manual for the C-120 automatic. If anyone needs one. 1976 Any chance you could scan into a pdf and add to the manuals library? We do have the 8-speed operator manual but unfortunately there are no wiring diagrams in it. Garry Share this post Link to post Share on other sites
Thatoneguy 197 #24 Posted July 12, 2016 sure it may take me a couple days but I can get it done. I believe there is a wiring diagram in mine. Share this post Link to post Share on other sites
