jump start a diesel.... - PeachParts Mercedes-Benz Forum

vwbuge · #1 07-25-2002, 10:44 PM

Never had any probs whatsoever with my car starting before......never left the lights on before either.......Tried to get a jumpstart off a Ford diesel pickup (2 batteries)....no go....Hooked up a battery charger and left in on for 15 minutes...voila!! It started right up....my point......I figure the diesel draws too many amps for the jumper cables to handle????? Are there special cables for diesels????

Fisherman · #2 07-25-2002, 10:58 PM

Not special cables but as with anything you get what you pay for...
Did you leave the truck hooked up for a few minutes before firing off the diesel? This would have the same effect as leaving on a charger.
Also are you certain that you had good connections with the cables? Quite often they get used and abused and I have found that when needed they won't handle the load.
Just my .02...

JohnM · #3 07-26-2002, 12:08 AM

Also when you buy jumper cables check the gauge of the wire. I buy the larger wire (smaller number = larger wire = handles more amps).

JohnM 1983 240D 4sp 154K

190D22 · #4 07-26-2002, 01:09 AM

hmm that doesn't seem right. That ford diesel should have gotten yours going nicely... When my battery was very weak, before I got it replaced, I had to jump start my 190D off of my grand cherokee. My battery had enough to preheat, but not enough to crank. So what I did was preheat off of my battery and then start from the jeep when it was running. The connections were + on both batteries, - on the jeep battery, and a nice place on the engine on the 190 was my - for it. So I left the +'s connected, and had my dad standby with the - and when the preheat was done he connected the cable to my engine and I immediately cranked and she started right up. Had do this at least 3 times before I finally replaced the battery.

My reasoning for the connections I made. Last connection away from the dead battery because dead batteries sometime leak hydrogen, extremely explosive, and the spark of the last connection would make your car the next hindenburg! The connection directly to the engine for the - is because duh that's the common and since we're trying to get the starter going the connection is about as close as possible to the starter so the current has less to flow through to get to the starter. But that's not a big deal.

I can't tell you why yours didn't just start right up. Especially with the truck being the beast it is power wise, two batteries and all. Maybe somehow that your battery being so dead that it was being a current draw and wasn't allowing the starter to get enough power to crank the engine. I don't know. But it's good you got her going again!

vwbuge · #5 07-26-2002, 07:37 AM

Just a mystery I guess. Once I got it going I drove it for an hour and took it home. Haven't touched it since....fires every time.

#6 07-26-2002, 07:57 AM

you shouldnt have a problem i jump start my 300 with a 84 cavalier 4 cylinder and i use el wal-mart cheapo's jumper cables

just gotta let it sit for about 3 minutes

jeff

Jim Anderson · #7 07-26-2002, 11:53 AM

You can only get so much power through them. Part of it is the wire size, the other is the clamp and how much meat it can grab. Try using two sets of cables. I once got a diesel started using two cars and two cables.

lrg · #8 07-26-2002, 01:05 PM

The weak point in the jumper cable connection is usually the clamps. You need to be sure they are really making a solid contact and on as much metal surface as possible. 190D22 is right, ALWAYS connect the last clamp on the body or engine of the dead car away from the battery. When they blow, and they can really blow, they throw battery acid everywhere. I usually do the positive cable first on the respective battery posts and wiggle them to be sure there's a good bite. Next the good battery neg terminal and last the dead battery side car body...I usually look for a bolt down on the fender or front side of the engine. Avoid the exhaust because between the gaskets and the rust you may not be getting the ground you think you are.

dabenz · #9 07-26-2002, 02:00 PM

My vote's for a bad jumper cable connection, either corrosion on the teeth of the jaws or the jaws not biting.

The tip about one connection to bad battery being away from the battery can't be repeated enough. You only have to witness one battery explosion to be a believer. Also put your sunglasses on if you don't wear glasses. Everything else can be fixed.

190D22 · #10 07-26-2002, 04:18 PM

I've got some home made jumper cables my old man made a long time ago. It's got some industrial gauge wire that's on a whole 'nother gauge scale. He got it when he worked for jeffery mining equipment back in the day. He used the clamps from an old set of cables. The larger size wire the better. You're drawing a few hundred amps when you start that car, the wire needs to handle that! It is wise to move the clamps around when you make connections to insure good continuity. Making your own cables allows you to get some huge wire. Man are the cables STIFF when it's cold out!