Alternator Upgrades (sort of)

Hi,
I have a 98 XJ Ltd.
A friend told me that if you run an extra 4 gauge wire direct from the positive terminal on the alternator to the positive terminal on the battery, you could get an extra volt output. Has anyone tried this ? Would I do the electrical system any damage ?
Thanks for your help.

The OEM lead there is, as I recall, 10 gage - so going to 4AWG would definitely be an upgrade.

Voltage output is regulated by the PCM, so it won't increase. However, you'll get full voltage to the PCM for distribution, and you'll also have less conductor resistance (meaning more current available.) It's not going to increase the output, just decrease the drop.

CAVEAT - By replacing or augmenting the OEM lead, you will also be eliminating an OEM circuit protection device - the two MAXI 60A fuzes labelled "Alternator" in the PCM. Will this be a problem? I don't know - but it's something I warn all my customers about as well - I'd say it's about 50/50 on replacing that lead or leaving it for later. I would go so far as to suggest, if you do this, installing a fuze inline (AGU or ANL lines will give you the rating you'll need) if/when you replace the lead.

5-90

Do you have a problem? If so could you give more details please or is this just a "what if" thing.
Many plow owners do this sort of thing. Often after going to a higher output Alt. Even with a standard output Alt many times the stock lead was not intended to handle the heavy sustain load a plow lift or winch if use a lot can apply.
Also note that when the lead is upgraded the ALT. life is often shorten when used under heavy sustain loads. The larger lead will let the ALT load more, it may run hotter. Then pop goes the diodes.

badron said:

Do you have a problem? If so could you give more details please or is this just a "what if" thing.
Many plow owners do this sort of thing. Often after going to a higher output Alt. Even with a standard output Alt many times the stock lead was not intended to handle the heavy sustain load a plow lift or winch if use a lot can apply.
Also note that when the lead is upgraded the ALT. life is often shorten when used under heavy sustain loads. The larger lead will let the ALT load more, it may run hotter. Then pop goes the diodes.

Click to expand...

the larger lead has no negative effect on the alt. if anything it allows less voltage drop and allows the alt. to work easier. if you have a high demand electrical system constantly working a low amp alt. your gonna tax it no matter what size the alt lead is. the only thing to worry about is removing the fuseable link between the alt and the bat. when upgrading this can easily be fixed by installing a breaker.