I find it hard to believe the connectors are the problem. If they are making poor contact, they will get hot fast.
The only sure way to diagnose the problem is to put an amp-meter inline with each glow-plug and see how much current it's drawing. They should all draw the same - 8 - 10 amps at 6 volts. You can check them one by one by using a jumper from a 12 volt battery through an amp-gauge if you want - instead of jerking around with the relay or controller. If testing with 12 volts - amps will be 4-5 on each plug. Don't do it more than a few seconds at a time.
In regard to the correct plugs? The ZD9 Berus that were mentioned in other replies are for the 1987 6.9s only - as well as the later 7.3s up to mid-1994. The ZD9s will work in your engine but they draw less amperage and the timer won't work exactly as it should. The ZD9 draws 7.4 amps at 5 volts DC. Your 6.9 system is setup to use the earlier plug that draws 9 amps at 6 volts DC.
I've got a 1985 with the 6.9 and correct plugs and it starts fine in cold weather. The early General Motors 4.3 and 5.7 diesels use the same plugs.
I also have a 94 with a 7.3 turbo and the ZD9 type plugs and it also starts find - no better or worse than the 6.9.
All 6.9s up to 1987 use the following: Delco 8G, Beru 0 100 271 102 or 835MJ or GV835, Bosch 80024, Autolite 1107, Wellman GO80 or dual coil GO88, Champion CH80, Ford and Motorcraft ZD1A or E5TZ12A342B, General Motors 5613680, IH/Navistar - 1804211C2, Lucas/Delphi DS090A, Delphi HDS305
1987 6.9 and 84-94 7.3 diesels use these: Beru ZD9, Delphi HDS307, Champion CH84, Lucas/Delphi DS092A, WAP 84
If you decide to put in a manual push-button then it doesn't matter much which plug you use - except - make sure you get a dual-coil self-regulating plug or you'll wind up ruining them.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Product Review: Black Tire Paint - by Staff. I have been fortunate in that two of my tractors have had rear tires that were in great shape when I bought the tractor. My model "H" even had the old style fronts with plenty of tread. My "L" fronts were mismatched Sears Guardsman snow tires, which I promptly tossed. Well, although these tires were in good shape as far as tread was concerned, they looked real sad. All were flat, but new tubes fixed that. In addition to years and years of scuffing and fading, they had paint splattered on
... [Read Article]
Latest Ad:
2022 John Deere 5045E, 4wd, front end loader and 3rd function with grapple. 120 hrs, 55k new, must sell
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.