Hot Rods Battery in the trunk

The redneck bad ground starter test: attach a single jumper cable to the battery ground, as the starter is turning over attach the other end to the starter case/bolt/main body, the idea being to ground the starter. If the cranking RPM picks up, Viola!, bad starter ground. Usually due to paint on the block, rusty attaching hardware or any other such issue that could impede current going "home". Just sayin, carry on...

 

With the editorial (aditoral??) direction the magazines have taken in the last few years, I would say
"corn kernel in a pile of steaming turds" is a closer ****ogy...

 

when a beemer/ mercedes /porch . dies over here they are often snapped up and go to a specialty s****per and parted out , only seen one BMW at my local yard and it wasn't there long as it was sold to parter and they put a sign on it to make sure it wasn't scavenged . the other yard I go to ( latemodel yard that does wreck towing , often if the car is involved in a wreck the insurance company buys it and has it sold for parts and they send it to the specialty houses or there rebuilders for parts .

 

your not supposed to rely on the ball or reciever for the ground thats why they put a ground lead in the wiring harness . this is one of the biggest problems I have with people with electric trailer brakes not working or light problems on a non brake/bump brake trailer . they give you a ground wire ( white) use it and connect it to the trailer frame not the hitch ***y ... even on semis there is a ground wire in the harness of the 7 way plug , often I find that lazy mechanics try to use the fifth wheel a a ground and create all sorts of problems with lighting or new abs systems .

 

Look for dead Jag XJS's. These have the battery in the trunk and use a hefty 2/0 cable. They're a pain to get off the car, but have a heavy-duty battery terminal. I think the Jag sedans use the same set-up, worth a look.

 

one thing I remember from Interstate and the Deka battery guys when they had there seminars is that a smaller engine ( cylinder number ) is harder to start than a v-8 or v-6 as there is less firing cycles per revolution and thats why smaller cars needed higher amp batteries and often them engines had a higher compression ratio than a v-8 too .

as for cables learned from trucks and heavy equipment , ground cable to the block and positive cable to the starter then a aux cable to the body and frame from the ground and positive smaller cable to the fuse block .yes more wires , but a better circuit connection and less problems .. and if its a street car weight is not a issue , only when I wire a race car do I look at the least amount of wires needed . and often take the wires to the limits of amperage . but we also try to keep the wiring short .and a race car it still gets 2 heavy leads from the battery to the block and one heavy from the alt back to the 4 pole switch . and the positive then comes from the starter supply hot . but in a race car weight is a enemy and copper is heavy . ( weigh a wiring loom some times ) and ounces add up to pounds quick .

 

VWs Beetles used them also . I try to use them on the rewires I do as they are more flexable than the cable ( and pulling lugs ( soldered and crimped )) and often have less problems

 

Odd... has to be designed other than BY Lucas the prince of darkness electronics

 

Yeah, it's almost the only electrical part on the car that's worth salvaging. They also have a cool bulkhead fitting for getting power into the cabin at the firewall. All the rest is typical Lucas.....

 

got a picture of it ?? . I have to figure out a way to get the wiring ( 10 wires) out of the car ( 50 Poncho) and not look ****py or allowing water into the p*** compartment .

 

It's basically one of these.... http://www.summitracing.com/parts/lng-45700
... except it has a 3/8 stud on one side and a long #10 stud on the other. Jag would run 5 wires when one of the right size would do; the XJS has 5 separately-fed fuse panels plus some inline feeds. But for getting power to your fuse panel or anything else that needs 12V battery power, it's great. The 3/8 stud in the engine compartment terminated the cable from the battery, then a shorter cable went to the starter off that stud.

But not quite what you're looking for... There's bulkhead connectors out there (Summit lists several) but I'm very partial to these... https://www.wirecare.com/deutsch-connectors.asp?type=industrial&series=dt&contacts=2
Not particularly cheap, but a first-cl*** connector. You can get either the male or female plug half with a flange on it for bulkhead use. Downside is you need a special crimper (although there's cheaper copies available on eBay that work just fine) and depending on the series type (DT, DTM, etc) you have to pay attention to current ratings. I've tried the other brands/types (GM weatherpac, AMP/Tyco, some others) and these are by far the best of the lot. Fully gasketed/sealed, easy to ***emble/dis***emble (once you know how! LOL) and made from an extremely tough plastic that doesn't break. I know, I sound like an adverti*****t, but after screwing around with the others, I'll never go back....

 

I have a few of those laying around from big trucks .

Yea Deutsch' s are great ford has been using them for a while on some models , I prefer weatherpack ( its a Gm thing ) I have one of these but it it kind of looks out of place on the firewall was thinking on trying to hide it on the side of the firewall in the fender . and run relays to operate the headlights as I also have the box they use to wire the new Gm positive studs too .

 

What............... Old E36's are a worthless piece of **** that is best described as "bankruptcy on wheels"
A $1500 E36 would be concourse condition. [they are a 20 year old liability now]
A good engine is worth the value of the car because they all have cracked heads ,but the labour to swap engines would be cost prohibitive.
I can't see the battery cables being a high demand item, unless the s****py is off his meds and suffering from delusions

 

beemers are not a popular car and they like mercedes have there own special yards. most of the yards I know of only cater to american and jap built cars ( and some vw and volvo ) , but the others they go to other places as there parts are in demand , kind of like you guys when you come here looking for parts on vacation for your chevys and old fords ..

 

Maybe in central Illinois.

I just walked back from the corner store, and counted 11, in just two blocks of my neighborhood.

 

Last count, there were 23 of them (BMW E36) at the Modesto Pick & Pull...There is a number of them in Merced, too. This area is anything but 'sophisticated', se habla espanol signage abounds.

 

You make a good point about a little resistance having a bigger effect on lower voltage circuits and that voltage drop is the main concern. However, I think you and some others carry a good thing too far.

If the only consideration was loss of electricity, 4/0 wire to and from the starter would be the way to go. However, many cars will start just fine with some loss of electricity. If it does, then the larger size wires or electrically better methods are not needed.

No one can argue that larger cables conduct more electricity. But an argument can be made that it's not needed if the car will start safely and reliably with smaller ones.

Likewise, grounding through the frame may not be as good as running a ground cable directly to the starter, but grounding through the frame will be good enough for the majority of cars.

The advantages of using smaller wire and grounding through the frame are:
1) It costs less.
2) It weighs less.
3) it's simpler to route.

Of course, you don't want too small of wire. People seem to go to extremes and forget that there is a middle ground that is, "good enough."

As an extreme example, running AC through the battery cables would have even less voltage drop than DC. But we don't do that, of course, because DC is good enough, less expensive, simpler, reliable enough, lighter (no transformers) and costs less. The same, to a lesser extent, can be said of running bigger cables than needed.

 

Sorry, but you lack an understanding of how electricity works. First, it doesn't matter is you're using AC or DC; you'll have the same exact drop in a given size/length wire at a given load, it makes zero difference if it's AC or DC; in fact, it doesn't even matter what voltage it is. You'll have the same drop in volts no matter what. Now, the percentage of drop will change with voltage changes (which is one reason why AC systems operate at different voltages) so a lower percentage is wanted for system efficiency. Look here: http://www.calculator.net/voltage-drop-calculator.html? and play with this a bit. You'll note that changing voltage and/or AC single-phase or DC has no effect on the voltage drop, only the percentage of drop.

What we're offering is a way to calculate what's needed. You seem to be saying 'try something, it'll probably work'. And in many cases, you'll be right. I've seen plenty of badly-designed circuits work... until they don't.

One thing I didn't mention is where that 'dropped voltage' goes; it just doesn't disappear. It's converted to heat, and heat is the enemy of electrical systems. As an example, a 1/0 cable 14' long with a 300 amp load on it at 13 volts will drop .41 volts. Watts is volts times amps, so that drop will produce 123 watts of heat and consume nearly 10 amps doing so. Doesn't sound like much, but try touching a 100w light bulb that's been on even a short amount of time....

A 4/0 cable would be an extreme example; most cars won't need that. But what may be 'good enough' most of the time could cause a catastrophic failure under the 'wrong' conditions. When doing electrical, too big is always preferred to too small.

 

Lots of highway trucks run the ground cables direct to the starter body, then to the body and frame from the same starter post.

 

I'm going to agree with Steve here....... Cheap/Easy doesn't equivalate proper/correct....... many way's to "skin a cat" you can use a dull knife and get it done,but at what cost further? Knowing electrical/a system demands are not by any means- free/easy......Might work in one car,but might not work in another.......
Supply and demand.

 

Think of it like positive and negative numbers, once you hit zero the bigger number is the smaller number. Welding cable is negative numbers so 0 is 00 is -2 and so on and so forth.

 

I've still GOT my set of OO [ double O ] jumper cables 25-30 feet long I rigged up to be plugged INto recepticals mounted on Beulah's front bumper above the licence plate -- I could pull up beHIND a stranded vehicle and jump them w-out havin to manuver to be beSIDE or in FRONT of em [ safer when in freeway situations ]





there were ALso plug ins for an "over the side floodlite" on a 30 ft cord for lightin crash scenes off the road and down an embankment - annnd for engine heater [ for winter warmups ] and battery charger. the RED door was for positive cable and the littl red lite on top indicated that the power was ON [ via solonoide ] *when* the solonoide was *on* a red led and a beeper indicated on the dash as well -- IF I had not takin this precaution, Beulah would have BURNED as well from that OO cable connection bein shorted by the crash damage.



These were all destroyed in the crash that "killed" Beulah back in 2011 and I haven't REdone them as I NOW have a "HD portable" booster w a 75DT battery IN it that I carry TO the disabled vehicle and use to JUMP it -- or if it's alternator is dead, I'll inSTALL my battery IN their vehicle to gittum HOME -- [ they're supPOSED to bring my battery BACK to me on gittin their alternator fixed -- ]

ALL *promise* to -- MOST DO - but them that don't well, *that* HURTS me finanicaly

anyways - them OO cables have never let me down

 

"Although resistance-free connections, wires and cables would be ideal, most of them will contain at least some voltage drop. If your manuals do not list voltage drop values, use the following as maximum limits:

• 0.00V across a connection
• 0.20V across a wire or cable
• 0.30V across a switch
• 0.10V at a ground "

http://www.fluke.com/fluke/uses/com...articlecategories/electrical/diagnosevoltdrop

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Delco Remy says 0.5 Volts drop in either hot or ground circuit (bat post to final connection) when p***ing a whopping 500 amps. If using the started to load the battery the amps are probably about half, so I'd expect less than 0.3 volts.
Page 17 here -
http://www.delcoremy.com/Do***ents/diagnostic-manual.aspx

I definitely would not replace/"upgrade" a cable in decent mechanical condition if the voltage drop results were acceptable.
Or, with a frame grounded set up, I'd step the multimeter probes along the wiring to test the short cables and connections thoroughly, expecting to find a problem with the the cables/connections, and NOT the use of the frame as the front to rear "cable".