Older friend of mine has a 1976 9000 series ford semi with a Cummins 350 in it. He drove it to its current parked position about 5 years ago. Decided to see if it would fire up today. Bought some new batteries. You hear something under the dash click but it makes no attempt to turn over. I jumped what looks like a starter solenoid And it spins the starter but no engagement of a bendix at all. Looking at it a little more, I’m not quite sure how this is supposed to work. What I mean is a typical starter solenoid you’ve got a battery source on it, another fat line that goes to the starter itself. But solenoids typically have a smaller 12v wire that when powered would jump the solenoid and turn it over. I see no such wire so I’m wondering if there is some other component on these trucks that maybe will cause the solenoid to pass power to the starter and cause The bendix to activate as well. I‘m not a diesel truck person but figured someone else might be and can fill in the blanks for me. Anyone care to offer some knowledge?
That solenoid has an “S” terminal with a wire going to it. One terminal is ground, the other goes to the starter button. They are just hiding from you under 40 years of gunk.
Thx. I’ll take a deeper look tomorrow.
Good luck. She looks like a helluva rig. Keep us posted. If She don’t crank over, just pull her until the water boils. They don’t make em’ like that anymore.
That's a 40MT--those solenoids were known for issues, moisture is one. Better off to change it to a Delco 8200308 if it ends up needing one. As long as 12V.
Thx. I’m gonna guess it will fire up. He’s got an 8000 series tandem dump truck he uses on a regular basis. Need to check if it’s getting 12 volts at that solenoid. Then I’ll figure next steps.
Buy a pack of zip ties and clean up those spider webs before I shoot myself! LOL
Glad you said that, If I did well-----------------------.
Those are nothing compared to the wasp nests that were in the cab.
He wasn't referring to *actual* spiderwebs...
Wasp nests. *
Well you guys were all right. There was a 12v hidden behind a black line. We gave it 12v and a baby shot of either and the old beast fired up! Not sure where it’s being robbed that 12v when you push the actual starter button but suspect maybe a mouse is involved. Damn thing runs good too. Found out today my friend has owned this truck….since 1982! It’s got a whopping 151k miles on it. We didn’t have such good luck firing up his ditch witch with the backhoe on it. It didn’t like the ether. We had to try it a few times so we used up our luck. Someone had pulled the fuel line off that one which we didn’t notice until we saw it running freely. Only took a minute to put that back on but too late. The damage was done. Blew a head gasket. Thx again guys!
I've always been a small guy, weighing in around 130 to 140 all my life. I swear, those old 40MT Delco starters, seems like they weighed as much as I do, a fight every time I had to change one. One thing I'm certain of, I do not miss them.
Bad thing about them and especially that one from setting. Likely solenoid contacts will stick stay engaged and keep motoring while engine is running. Common issue with 40MT's.
Good point.
One thing about those old 40MT's once started--it was best to watch amp/volt gauge to make sure it didn't bury on the negative side. Otherwise it's a scramble to remove ground cables if no disconnect switch or lugs. It will turn the insulation on battery cables to flames in no time.
The 943 did that once. It runs all day at wot. The fields where cut off from the armature windings flying out
And, for that reason alone, battery switches are so important. I’ve had a few intense moments. Especially, with guys trying to jump start or crank with low batteries. You know, until now, I never thought about the 40MT with square back solenoids being more prone to that. In every case, it was a 40MT. When Truck Shop mentioned that, it clicked. Just like the solenoid did before it welded it self together. Last time was at the Port of Anchorage. Kenworth package truck loaded with methanol totes. The driver started the engine and failed to notice the starter was still cranking. Driver went inside the warehouse to warm up. I was walking by and noticed the flames. It was close enough to the warehouse door with a hydrant w/hose.
Silver alloy or copper contacts--the better solenoid used silver alloy, better arc resistivity plus from setting long periods of time less corrosion/resistance. * A great combination for a restaurant type grease fire in a vehicle setting is a typical leaking two stroke with years of build up inside frame rails where cables were typically run to starter, combining the notorious 40MT. * Corning Cal, 1980. Heading south on 5 I could see black smoke rising in area of Dudley & Petty truck stop, my fuel stop. Red lights a flashing water a hosing--a melted 75 Pete 352 sporting a two stroke V-8 that the starter stuck, driver cold started it and went in to have a set down plate of biscuits & gravy with a extra pork sausage patty on the side with two eggs. While he was performing graph surgery on his log book from the previous days heroics dodging rocks falling from canyon walls and lightening bolts. Only to lookup to see what the commotion was about--his truck sizzling in the parking lot. Probably wasn't really what took place with him, but he did fire it then walk away leaving everything to chance. * Which leads too why it was such a greasy mess, if he did that regularly, it just sat there cold slobbering oil not being throttled up.
Is there anyway to keep bees,mice and other things out of old rigs? I have been using mothballs and they seem to help some .
I had to pull one off a AC-HD-12g buried between the loader arms and the engine.....I rigged up a rope to lift it out.
That's why you need to get your scratch paper straightened out before going to bed.
Fatigue will cause a bigger mess.
I had to do the same thing on an International TD175B traxcavator, what a PITA!
Try changing a starter on a Cat 931B with the arms down if you want to exercise your right to new curse words.