Any limitation to direct B+ wire connections

[sagaboy]

Currently, a single B+ wire go to the starter motor and continue from there to the battery +12V terminal. My car tap the power supply from the battery for the fan to cool the condenser-heat exchanger. I was wondering if I can pull a fused line directly from B+ directly (which is closer to the cooling fan) rather than the present longer wire loop circuit to reduce voltage drop supply to the battery and front of the car fused panel.

In short--are there any limitation to direct B+ wire connections.

[Piledriver]

Currently, a single B+ wire go to the starter motor and continue from there to the battery +12V terminal. My car tap the power supply from the battery for the fan to cool the condenser-heat exchanger. I was wondering if I can pull a fused line directly from B+ directly (which is closer to the cooling fan) rather than the present longer wire loop circuit to reduce voltage drop supply to the battery and front of the car fused panel.

In short--are there any limitation to direct B+ wire connections.

Only the size of the feed wire.

It's essentially connected directly to the battery + terminal, from an electrical standpoint.

OTOH, it's on the wrong end of the car.
Any direct connection from the battery would(electrically speaking) do the same.
(Use a relay, obviously, as has been discussed)

[david58]

Any connection at the battery terminal will corrode. Not a good thing to have. The terminal on the starter would be better. Or a junction block off the starter terminal if you are making multiple connections would serve better. Here is a junction block I made for my baja that is behind the passengers seat. I made it out of scrap corian counter top material.
http://i892.photobucket.com/albums/ac12 ... NY0301.jpg

http://i892.photobucket.com/albums/ac12 ... NY0299.jpg

http://i892.photobucket.com/albums/ac12 ... NY0300.jpg

http://i892.photobucket.com/albums/ac12 ... NY0305.jpg

http://i892.photobucket.com/albums/ac12 ... NY0302.jpg

Note: pics are in my photobucket account but will not post in forum, because of the new settings.

[Piledriver]

Everything will eventiually corrode if you have a conventional wet cell battery.
A hole will eventually even develop underneath it.

Imagine how many more 914 Porsches would be around today if only AGM batteries existed back in `70...

[Dale M.]

A bit of extreme cleaning of battery terminals and associated connectors and a liberal amount of dielectric grease goes a long way to prevent corrosion/oxidation at battery terminals.... And another 'lectrical connections...



When I was still working in telecommunications before I retired, we used this product exclusively on all electrical connections from about 12 gauge wire up to 750,000 cm and we never experienced any corrosion problems inside connectors (connector to wire) or any corrosion between connector and bus-bars (bolted connections)... IT was even used on connections to wet cell storage batteries for backup power....



http://electricalsafetysuperstore.com/p ... -compound/

Dale

[Chris V]

Nothing saying you can't run a larger wire or simply add one if you find out you have too much resistance = voltage drop. You may even touch the wire to quickly see if you have overloaded it, it'll get warm if severe enough.

On Dad's `77 he had high resistance in the factory wiring through the left-hand side C-pillar to under the backseat...so I found a dealer dognistic wire from a late Beetle and trimmed it back a bit and installed it from the starter to the B+ as well, so there are two wires in parallel - and the system dramatically improved.

Whenever running things through the engine bay take your time and run them nice so as to take the abuse of the heat/vibration/oil/rain - wires are quick to be sucked into the fan.