I got the X9331 connectors male and female.

My plan is to connect one end to the connector under the dash,
run the wires to the amp under the seat. Run the wires from
the amp back to the dash to the other side of the connector
to use the wires that go to the speakers.

I have the base radio and will have upgraded speakers.

Assuming doing the wires right (I'm always really careful and
double check again and again) my car is not going to catch on
fire, right?

I've seen a couple of posts about people's cars catching on fire....

 

I just had my amp put in two weeks ago.

I had changed all speakers myself, but did not feel confident in doing the amp install myself. So I paid a local shop here in San Diego about $125 in labor to install the amp I bought elsewhere.

They did exactly what your plan was in terms of wiring. They picked up the speaker signals at the X9331 connector area, routed these to the amp (which took speaker level inputs), then routed the amp output back to the X9331 connector area where they where the signals were connected to go to the speakers.

I did not see whether they popped the pins out of the connector, or cut the speaker wire leads, or what. I did ask and they did verify that the non-speaker signals at the X9331 were still connected (i.e. these four pins need to still be connected). The eight speaker wires were crimped to a nine conductor speed wire and routed to the amp. The amp output also was routed back using speed wire, where it was crimped to the speaker wires.

I had run with my replaced speakers for over 20 months without an amp. Having had the amp for two weeks, I now wonder why I waited so long.

So, if you hook it up right, your car will not catch on fire

Good luck, and let us know how it goes.

 

Thanks. I'm really looking forward to getting this done.

I undid the speaker swap. It seems the main problem is
bad speakers and no power.

Where did they run the power to the amp?
(meaning where did they get the wires from the battery
into the car, assuming your amp is under the passenger seat)

 

There's already a neoprene type large "plug" on the firewall inside the battery compartment with wires to the passenger compartment. They used one of the spare "fittings". You should be able to find pictures in other threads if you use the search function. Power was then routed along right side of passenger side to amp under passenger seat. Speaker wires from / to X9331 was routed along driver side to somewhere in back where it was then brought across to passenger side and then brought up to amp. They took care to route power wires away from speaker wires.

If you do it yourself, just allow plenty of time -- the shop I went to took about 3.5 hours, though I was not the only car in their shop.

You're going to be really happy with the sound improvement.

 

I will search for that.
I've run power through the driver side that was not bad at all.
(for my devices)

I'll take a look when I get to it.

I don't really work at a hurried pace and also I'm always
getting interrupted so I actually figure all weekend to
put the thing in. Which is normal.