I need to install a couple of switches. I have run the wires to the fuse panel and now I want to tap into a couple of switched wires.
Which are the best switched wires to use and how do I locate them. I am not quite understanding the diagrams in the manuals.
This is for a 91GT.

TIA

 

Jim

Use a fuse tap to pull power - you can then fuse it at the Central Electric panel using the same kind of fuses the panel uses. I like ONLY the type shown at the bottom... most other types are not really good solutions... Waytek Main Page you will have to search for fuse tap on this site. Several other places stock these - sometimes even in retail... (Also see photo example below).

The place to tap depends on application.
1) Is it to be permanently on (risk of draining battery - don't do it unless functionally required)
2) On with ignition
3) On with accesssory position (and off while starter active)

Seems you want either 2 or 3

PLug the fuse tap in place of a fuse - then it has that fuse replicated on the tap - the other fuse is for your new circuit. Place the tap with the wire down since the ATC fuse input is always at the top.

For 1) 30 Bus - always on - use one of fuses: 16-27 - preferrably one of the lower current rated fuses.

For 2 ) 15 Bus - Ignition - Use one of fuses 39 - 45 preferrably one of the lower current rated fuses.

For 3) X Bus - Accessory - Use one of fuses 33- 35 preferrably 35 the lowest rated one.

The cigar lighter/accessory power is fed by X-Bus/Accessory so is OK to tap directly if thats your only method - CE Plug Pin O14. Thats Plug labelled O. The 15 breaks down to the 1 standing for 1st plug module - thats the left column of contacts and the 5 means terminal 5 thats the 5th one up (the top one).

HTH (do the fuse tap its better)

Note the fuse locations here are year specific to a '91 - check for other years.)

Alan

 

Alan,

Perfect!

The application is for a custom fan set up and an ic pump. So application #3.

Thanks a ton.

 

Jim, if you are running fans and an IC pump, you should probably consider running the power through a relay off the jump post, and use the switches to trigger the relays. I don't think the power tap Alan mentioned would be a safe way to tap that much power, since I don't think there are any fuse positions that can carry the extra 20-30 amps you seem to be talking about.

 

Er yes - Jim what kind of current are we talking about - I was assuming some simple accessories - these sound kind of heavy duty...

Agree with Dave if its in the 15A+ range better not to piggy back from an exiting a fuse - The engine jump post supplies the CE panel so it is a better place to make a tap - use thre switches wired as you have to control the relays. You can get nice relay boxes - look on Waytek - that encapsulate the relays and tidy the wiring - could attach to the fender bulkead...

Alan

 

This is another electrical keeper. Thanks guys! I didn't realize the fuses were grouped by buss as Alan describes. Cool.

 

The fans are wired to the post, The switch to the fans is what I am refferring to.
I will see if I a can find how many amps the ic pump uses but I don't think it's much, the wires from it are only 18 or 20 gage.

 

Jim - so are you saying they have a built in relay or controller and the switch is just light duty for control - if so good. 18 or 20 gauge does indeed sound fairly light duty..

OK sounds like back to plan A!

Alan

 

Yeah, that sounds a lot more like it! Also, see if you have an unused fuse position activated by the ignition that can be re-purposed for this.

 

Alan, Dave,

You guys are great, thanks.

Bill, finally got around to checking out you website. Lotta good stuff on there