QuestionQUESTION: Hey Brian,
Sorry, I haven't figured out how to post a follow-up to our original thread. This question pertains to the 2002 Buick Le Sabre and the IS77 modulator you've been helping me with.
I've received the unit and hooked it into the antenna line at the junction you mentioned, but I still haven't hooked up the power. I looked for the three-wire bundle (cigarette lighter) under the passenger knee-panel, but I can't find any bundles that have that exact description. The closest is 4 wires: Orange, Black, and 2 Yellow. Is this the one you mean? It's connected to what I think is the DIM module, since there are 2 larger bundles (widely varying colors) connected to the same box. It looks like the wires are taped, exit the foot cavity on the right, and may run left to the lighter over the metal sheet. Does this sound correct?
The only other small bundles of wires are two-stranded and appear to link to the glove box light and--possibly--the blower motor.
Finally, if the car has been off for well over the 10 minute timer on that line, will it be safe to do this job without disconnecting the battery? I know the battery is stuffed under the backseat in this car, and not dealing with it would be nice.
Sorry to pester you with a siege of questions. It's my first car project, and I just want to make sure I get it right. You've been a great help!
-Devin
ANSWER: Hi Devin,
Sorry about the long delay in answering your question.
My problem is that I'm going entirely from my memory of the last LeSabre I worked on. I'm not certain if the wiring I remember is present in all similar models--it's entirely possible that the plug I remember from my installation in a LeSabre isn't present in your vehicle.
The plug I used wasn't part of any module under the dash; it was just a junction point in the harness leading to the ashtray assembly. If the wires you're seeing are connected to a module of any sort, then they're not the same wires. You might have better luck if you try taking the ashtray apart and look for the wiring harness right at the cigarette lighter plug. Unfortunately, I don't remember enough about the car to tell you how difficult this might be.
If you haven't already, you'll probably want to test the cigarette lighter to make sure that it loses power after ten minutes, like the lighter in the vehicle I worked on. Again, this might not be the same in your car. The easiest way is to plug in any 12-volt power adapter that has a built-in indicator light; if the light goes out ten minutes after you close the door, then the cigarette lighter wiring should be safe to use. If not, or if you're unable to get to the wiring, you can check the electrical box under the back seat to see if a "RAP relay" is present. If so, I can give you directions for using that relay's output as a power source, instead of the cigarette lighter.
I know that just about all installation instructions will tell you to disconnect your battery before working with your vehicle's wiring, but I can tell you that just about all professional installers don't bother with this step. I don't think it's necessary to disconnect your battery, even if the circuit is live, as long as you're 100% certain that you're working with the cigarette lighter power feed and not some other wire. You're not going to get a shock from a 12-volt power wire, and as long as you're cautious and work with just one wire at a time, you're not likely to cause a short circuit. However, if you do accidentally short the wire, you'll just blow the cigarette lighter fuse. So, if you're comfortable with it, go ahead and leave the battery connected. You'll be fine as long as you only have one wire stripped or bared at at time, don't cut two wires at once, and make sure your wire strippers or tools aren't touching any metal part of the dash while you're working on the wires.
Good luck!
Brian
---------- FOLLOW-UP ----------
QUESTION: Awesome.
I was curious about removing the backseat anyway, since I wanted to check out the battery back there.
Is it easy to remove the seat? What does the relay look like and what side would it be on? Taking apart the ashtray looks impossible, so I'd love to hear your ideas on this relay. Hopefully I will find one in my car!
Incidentally, any idea why they would put the battery in that location? It was a huge hassle to find a place that had a proper replacement since it's vented. I finally had Sears just put in their "Platinum" model which doesn't release any gasses. Cost an arm and a leg.
ANSWER: Hi Devin,
Removing the rear seat in your vehicle is easy. From the front of the seat, push backwards on the rear cushion, while simultaneously lifting the front edge. It should come right out. The battery is located on the right side of the area under the seat; the relay/fuse box will be on the left (driver's) side.
You'll find a diagram of the relays and fuses under the lid of the relay box. The RAP relay, if present, should be labeled on the diagram. The trouble is, not every LeSabre is equipped with this relay (though I've found it more often than not). The relay is a small box with four legs that are inserted into slots in the electrical box. You can just pull the relay out of its mount, just like you'd pull a fuse out. Be sure to remember the orientation of the relay, so you can put it back in the same way it came out.
The relay terminals will be numbered: 85, 85, 87, and 30. When the relay is in place, there will be a voltage present on terminal 87 whenever the key is on, and after the key is turned off until you open the door. Power-wise, it acts just like the factory radio (RAP stands for "Retained Accessory Power"). If the relay is present, you can tap a power wire onto terminal 87 and tuck it under the sill panels, up to the front to power the IS77.
For this job, I like to use a special type of fuse tap, which looks like this:
http://www.qualitydist.net/pico-1593qt.html
You have to flatten it out and shape it differently to work with the relay, but when it's set up correctly, you can slide the relay terminal through the slot on one end, and connect your power wire to the other end using a .187 Quick Disconnect wiring terminal. I'd also suggest putting a fuse holder with a 5-amp fuse on your wire near the relay; that way, if there's a short on your new wire, it won't affect the vehicle's RAP circuit.
I'm really not sure why the battery was moved back under the seat in this car; I suspect the designers were trying to save space under the hood. It certainly adds to the cost of replacement batteries, but from a car audio installation standpoint, it makes installing an amplifier in the trunk much easier.
Hope this helps!
Brian
---------- FOLLOW-UP ----------
QUESTION: Okay,
I don't have a relay mounted in the fuse block, but there is a slot for it, which is labeled in the diagram. Is it possible to purchase one? If so, can it, the fuse tap, and wiring terminal be found at an automotive parts/home supply store or is the best route mail-order? I'm not opposed to that, if it's the only way. Maybe if the relay is unavailable I could still tap into the slot itself?
Do you have a recommended gauge for wires? I'll have to add a significant length to reach the backseat. Lastly, do I need to remove the sill panels to hide the wire or can it just be shoved under? If so, how do they come off?
Worst case scenario, I guess I could get a cigarette lighter plug and just stick it in the socket, since there is no visible way to remove its housing. Talk about an endeavor.
Again, sorry to bombard you with questions, but this is a very interesting project. Thanks for your help.
Devin
AnswerHi Devin,
I'm not sure whether adding a relay would work out for you or not. It depends on whether the source voltage and trigger voltages are present in the relay socket. You wouldn't be able to just tap into a slot without a relay; the relay itself generates the voltage that you'd be tapping for a power source. I've never tested the slots in a vehicle that wasn't equipped with the relay, so I don't have any definite information. Any auto parts store should be able to provide a relay; it's identical to all the other mini relays in the fuse box.
I'm also not sure where you can purchase the fuse tap I listed, other than online. (The wiring terminal should be easily available at an auto parts or hardware store). The fuse tap I linked is actually included with the Metra 70-2003 wire harness; that's where I usually get them, because I often use these harnesses but seldom use the taps. You might try visiting an installation shop that uses the Metra part, and see if they're willing to give you or sell you a spare tap.
As you mentioned, you always have the option to wire in a cigarette lighter plug and connect to power that way. It's not the most elegant solution, but it would work.
Some 18-gauge primary wire would be ample for your power wiring. The ground wire can be connected to any convenient metal structure under the dash.
Hope this helps, and I apologize again for the delay in answering.
Brian
