Diesel conversion. Relocate battery?

jolotter · Post by **jolotter** » Thu Nov 15, 2007 12:42 am

I've got my 1.6 TD engine on a jack in the engine bay of my ex-wbx. Tomorrow I'll bolt up the carrier bars. I'm thinking through adding the glow circuit.
The stock diesel vanagon has the battery in the engine bay and mine is currently under the passenger seat. Should I relocate it to the engine bay?

Here's my list off the top of my head of what this will involve.

-Wire from battery to starter. It's 2!! gauge. They will be much closer with the battery in the back. Will the shorter run between them offset the increased resistance from 24 year old wire or should I spring for new wire? With the WBX, sometimes I'd get smoke from the battery box on hot starts, (bad, I know.)

-Run a new 8 ga wire from the battery to the fuse panel.

-10 ga to glowplug relay. New wire. No doubt there's a spare wire in the wiring box at the front left of the engine compartment running to the fuse panel that I can use to power the low voltage side of the relay. And maybe a return wire for the little yellow light too. Is there a universal relay block I can mount the relay in if I use the VW part. Does the ford relay need a pin block?

The alternator's two 10 ga wires will just need to be shortened.

Seems straightforward enough.

Is there any reason not to do it? The only thing I can think is that when I do the WVO part, it might be nice to have some extra space back there for the dumpster pump or filter stuff.

Johann

libbybapa · Post by **libbybapa** » Thu Nov 15, 2007 8:56 am

Moving the battery closer to the engine will greatly increase the cranking speed of the starter (one of the most essential aspects of cold starts) and assist the glow plugs to glow brightly. On my '83 I am actually moving the battery out of the engine bay for a couple of good reasons. I will be placing it under the back seat and so the run to starter and glow plugs should be very similar (actually shorter run to the starter). I want to move the battery away from the heat of the engine - heat kills batteries. I am placing an oil to air cooler where the battery was in the engine bay and want to make room for the eventual mounting of an a/c compressor.

I can't tell from a distance what your cable condition is. If the battery is moved to the back, then heavy gauge cables shouldn't be too expensive. If in doubt...

I don't know anything about the Ford relay. You could certainly find a vw fuse panel in a junk yard and cut off all but the glow plug relay mount, or consider having a second relay/fuse panel at the back of the vehicle for power auxiliary stuff.

It seems like you've got the rest figured out. While you're re-wiring, consider adding a hot-start relay for your starter. It will greatly assist it's function and extend the life of your ignition switch.

Andrew

jolotter · Post by **jolotter** » Thu Nov 15, 2007 6:42 pm

That's a good idea to put the battery under the seat. I'll look into that.
Is a simple resistance check with my multimeter an accurate gauge of wire condition? What is the resistance of a good wire?

Johann

libbybapa · Post by **libbybapa** » Thu Nov 15, 2007 9:11 pm

Nope. Ohm meter on a battery cable won't be a useful test. Under load resistance can skyrocket (the theory behind a ballast resistor). The ohm meter will send such an insignificant current that you would be unable to tell if that was going to happen. A test of voltage drop across the cable while cranking would be more effective, but personally I'd rather replace the cables than try to engineer and effective test and be the one under the van testing the voltage while someone else was cranking...

Andrew

jolotter · Post by **jolotter** » Thu Nov 15, 2007 11:10 pm

Libbybapa wrote:

I'd rather replace the cables than try to engineer and effective test and be the one under the van testing the voltage while someone else was cranking...

Point taken.

Is there a place other than the dealer to get that red/white heavy gauge wire? The starter cable also has a heavy copper connector that looks application specific. Are those things available in a proper parts supply house?
Thanks

Johann

libbybapa · Post by **libbybapa** » Fri Nov 16, 2007 12:02 am

I think you would likely find what you want at your local auto parts store. I replaced the cables on my friend's Quantum recently and the local Checker had appropriate length cables with the right ends off the shelf. I forget the cost, but they didn't seem outrageous. Get the fattest gauge you can. If you switch the battery to the back you can run the ground to the drivetrain also. That will help with cranking speed and glowplugs as well, but be sure to clean or replace the transmission nose ground or your other electronics can get wonky.

Andrew

jolotter · Post by **jolotter** » Fri Nov 16, 2007 11:27 am

libbybapa wrote: If you switch the battery to the back you can run the ground to the drivetrain also.

Do you mean run a ground from the block or tranny straight to the battery ground terminal? Then the chassis electrics would go through the tranny ground strap and to the battery on that new cable. Would it be preferable to run another ground from the chassis to help the other electrics or is the circuitous route through the drivetrain fine.

johann

libbybapa · Post by **libbybapa** » Fri Nov 16, 2007 3:33 pm

Well, there are lots of ways to run it. Through the drivetrain is fine which is how the stock diesels do it. You could also ground to the chassis and then to the drivetrain, but for cranking and glowplugs I'd prefer the former. The rest of the electrics take second seat to those IMO. Unless I hear a better option, I will actually be mounting the positive to the post of the starter and the negative to one of the mounting bolts for the starter. The two cables will go through the same grommet in the "firewall".

Andrew

stopping · Post by **stopping** » Mon Nov 19, 2007 7:59 pm

Take a look at this chart for wire resistance.
http://www.valhallascientific.com/image ... regag1.gif

thee site is
http://www.valhallascientific.com/appli ... ns-6.shtml

jolotter · Post by **jolotter** » Tue Nov 20, 2007 12:39 am

libbybapa wrote: You could certainly find a vw fuse panel in a junk yard and cut off all but the glow plug relay mount, or consider having a second relay/fuse panel at the back of the vehicle for power auxiliary stuff.

Would a panel from a jetta or golf work fine? There's lots of them in the yards around here.

Turns out I had two right side engine carrier bars. I couldn't get the left one to fit and then I compared it to the other one, which was already bolted in. They're identical except one ihas rubber bushings between the mounting plates and the bar, the other is solid. I figure the rubber bushings. To their credit Quality German, from whom I bought the diesel van parts kit, immediately offered to send me the correct part or pay to have the other one modified. It hasn't arrived yet, but I still have many things to do and winter is knocking at the door. The left engine mount is currently on a jack stand.

At the end of the day, after experimenting with combinations of wbx and jetta TD water hoses and trying to imagine the copper four-way manifold, (where is that picture?) I threw the whole jumble of them in the hole, put the lid on and slammed the hatch. Only unlike bugs bunny, I couldn't start her up and drive off.

hoyt · Post by **hoyt** » Tue Nov 20, 2007 8:43 am

Is this what you are looking for:

viewtopic.php?t=6192&highlight=

libbybapa · Post by **libbybapa** » Tue Nov 20, 2007 9:52 am

Yup, any fuse/relay panel would work. I'd mount it under the rear seat as well.

The rubber bushed one is an '82 bar the solid version is '83 up. the '83 up (solid) ones are better.

Andrew

jolotter · Post by **jolotter** » Tue Nov 20, 2007 2:23 pm

hoyt wrote:Is this what you are looking for:

viewtopic.php?t=6192&highlight=

Thanks

Johann

Reiney · Post by **Reiney** » Thu Feb 21, 2008 12:27 am

I don't think it's worth it to go through all the extra work to move the battery as eliminating a couple of feet of 2 ga. wire is not going to make much difference. Also, the resistance of this cable does not change except for maybe an extremely small amount due to internal heating; of which there should be almost none. What changes is the voltage drop across this cable as you go from say 0 to 300 or so cranking amps (E = I x R)

According to the posted table, 1000 feet of 2 ga. is .159 Ohms. If your existing battery to starter cable is five feet, then you have a .000795 Ohm resistor between battery and starter. If your starter is pulling say 300 Amps, this cable will drop about .24 Volts. If you move the battery and now have a 2 foot cable and are pulling the same 300 Amps, your voltage drop is now about .1 Volts. This is a lot of work to eliminate a .14 Volt drop. I don't know the actual current draw of the diesel starter but even at twice that amperage moving the battery only gives you a few tenths of a volt improvement.

Usually, it's the connections that are the problem. Put new ends on the existing cable or clean the ones that are there and then buy yourself the largest battery that will fit under the seat.

For glow plugs, I mounted my relay on the firewall and ran a short piece of #8, through one of those large-sized ATC-style fuses (50A I think), and then put a lug on the end and connected it to the 2 ga. cable at the starter. Total cable length is about 18" and it seems to be working fine so far.

Go with the new battery and as Andrew suggested, save the passenger-side D-pillar location for an oil cooler which I think is a must-have.

I'm starting my WVO conversion next month and finally all three vehicles will be diesel/WVO. Looking for creative tank ideas if you've got any!

Reiney

jolotter · Post by **jolotter** » Thu May 01, 2008 10:19 pm

Reiney wrote:
I'm starting my WVO conversion next month and finally all three vehicles will be diesel/WVO. Looking for creative tank ideas if you've got any!

Reiney

At first I thought I'd use a syncro tank for the WVO, but then I found out the price for one of them. Now i'm thinking of a round tank in the spare tire clamshell for the diesel with a filler on the driver's side wheel well, opposite the stock one. Then I'd have to mount the tire somewhere else.

I have a 5 gal marine tank I could put under the back seat, but I don't want the diesel in the passenger compartment.

I'd like to see some pics of your WVO setup.

Johann