2004 330rx Tow Hitch Electrical

[carterboy]

I thought I had finished installing an OEM tow hitch on my 2004 330RX, but when I tested for voltage at the rear connector, I got nothing! The dealer tells me I need a junction block assembly because the vehicle did not come with a tow prep package. I still have the rear cargo area disassembled to gain access to the cable connector & floor grommet. Can anyone tell me where the junction block is located and how to replace it? Thanks!

[Wilson2007]

I thought I had finished installing an OEM tow hitch on my 2004 330RX, but when I tested for voltage at the rear connector, I got nothing! The dealer tells me I need a junction block assembly because the vehicle did not come with a tow prep package. I still have the rear cargo area disassembled to gain access to the cable connector & floor grommet. Can anyone tell me where the junction block is located and how to replace it? Thanks!

Carterboy - if the 330 is the same as the 350 - from other threads on this site about hitches, the junction block plugs between the hitch wiring and where it connects inside the vehicle. In my Canadian 350 - I did not need the adapter as they are already wired for the hitch connection. Do some searching for hitches and install - you should find more info.

Wilson

[GDixon]

I thought I had finished installing an OEM tow hitch on my 2004 330RX, but when I tested for voltage at the rear connector, I got nothing! The dealer tells me I need a junction block assembly because the vehicle did not come with a tow prep package. I still have the rear cargo area disassembled to gain access to the cable connector & floor grommet. Can anyone tell me where the junction block is located and how to replace it? Thanks!

You have to buy a separate junction box if the RX did not have a tow package. The directions with the box will tell you where to plug it in. There is also a fuse in the fuse box that may need to be purchased and installed to get electric to the hitch.

Where did you plug in the hitch under the cargo area? There shouldn't be a connector that fits the one that comes on the hitch. Also, the hitch cannot be just spliced into the car's electric because of voltage differences. You will not get 12V at the hitch with a splice.

Check this post for the part number of the converter (junction box assembly). The part number may vary by year but it is a start.

http://us.lexusownersclub.com/forums/index...ic=39543&hl

[carterboy]

I thought I had finished installing an OEM tow hitch on my 2004 330RX, but when I tested for voltage at the rear connector, I got nothing! The dealer tells me I need a junction block assembly because the vehicle did not come with a tow prep package. I still have the rear cargo area disassembled to gain access to the cable connector & floor grommet. Can anyone tell me where the junction block is located and how to replace it? Thanks!

You have to buy a separate junction box if the RX did not have a tow package. The directions with the box will tell you where to plug it in. There is also a fuse in the fuse box that may need to be purchased and installed to get electric to the hitch.

Where did you plug in the hitch under the cargo area? There shouldn't be a connector that fits the one that comes on the hitch. Also, the hitch cannot be just spliced into the car's electric because of voltage differences. You will not get 12V at the hitch with a splice.

Check this post for the part number of the converter (junction box assembly). The part number may vary by year but it is a start.

http://us.lexusownersclub.com/forums/index...ic=39543&hl

[carterboy]

I thought I had finished installing an OEM tow hitch on my 2004 330RX, but when I tested for voltage at the rear connector, I got nothing! The dealer tells me I need a junction block assembly because the vehicle did not come with a tow prep package. I still have the rear cargo area disassembled to gain access to the cable connector & floor grommet. Can anyone tell me where the junction block is located and how to replace it? Thanks!

You have to buy a separate junction box if the RX did not have a tow package. The directions with the box will tell you where to plug it in. There is also a fuse in the fuse box that may need to be purchased and installed to get electric to the hitch.

Where did you plug in the hitch under the cargo area? There shouldn't be a connector that fits the one that comes on the hitch. Also, the hitch cannot be just spliced into the car's electric because of voltage differences. You will not get 12V at the hitch with a splice.

Check this post for the part number of the converter (junction box assembly). The part number may vary by year but it is a start.

http://us.lexusownersclub.com/forums/index...ic=39543&hl

[carterboy]

I thought I had finished installing an OEM tow hitch on my 2004 330RX, but when I tested for voltage at the rear connector, I got nothing! The dealer tells me I need a junction block assembly because the vehicle did not come with a tow prep package. I still have the rear cargo area disassembled to gain access to the cable connector & floor grommet. Can anyone tell me where the junction block is located and how to replace it? Thanks!

You have to buy a separate junction box if the RX did not have a tow package. The directions with the box will tell you where to plug it in. There is also a fuse in the fuse box that may need to be purchased and installed to get electric to the hitch.

Where did you plug in the hitch under the cargo area? There shouldn't be a connector that fits the one that comes on the hitch. Also, the hitch cannot be just spliced into the car's electric because of voltage differences. You will not get 12V at the hitch with a splice.

Check this post for the part number of the converter (junction box assembly). The part number may vary by year but it is a start.

http://us.lexusownersclub.com/forums/index...ic=39543&hl

Thanks for the replies. I have the junction block assembly on order from Lexus of Roseville, California. They told me that no directions come with the part, but they think it goes under one of the rear seats. I plugged the connector from the OEM tow hitch wiring into the receptical located above the floor grommet in the rear cargo area (driver's side). There is a 30 amp fuse (#15) in the engine compartment for the tow hitch circuit. It was already installed and checked out OK. I guess without the junction block, there is no power available at the connector. I just hope I can find the old one & replace it with the new one without taking anything else apart.

[GDixon]

There is no "old" converter (junction block) to replace. It is an additional item that has to be plugged in to the car's circuitry and then the hitch wiring plugged into it.

Perhaps there is someone on this forum that has actually installed the part that can give you a hint on where the pigtail to plug it in is located. My RX has the tow package and am not sure where it is.

Another option is to take the car and converter to a Lexus (Toyota) dealer with the cargo area still disassembled and say, "How much to plug this in?". It can't be very much. Well, that is if you go to a Toyota dealership rather than a Lexus one.

[carterboy]

There is no "old" converter (junction block) to replace. It is an additional item that has to be plugged in to the car's circuitry and then the hitch wiring plugged into it.

Perhaps there is someone on this forum that has actually installed the part that can give you a hint on where the pigtail to plug it in is located. My RX has the tow package and am not sure where it is.

Another option is to take the car and converter to a Lexus (Toyota) dealer with the cargo area still disassembled and say, "How much to plug this in?". It can't be very much. Well, that is if you go to a Toyota dealership rather than a Lexus one.

[carterboy]

I thought I had finished installing an OEM tow hitch on my 2004 330RX, but when I tested for voltage at the rear connector, I got nothing! The dealer tells me I need a junction block assembly because the vehicle did not come with a tow prep package. I still have the rear cargo area disassembled to gain access to the cable connector & floor grommet. Can anyone tell me where the junction block is located and how to replace it? Thanks!

That is a good idea. I think the part should arrive today. Maybe I misunderstood, but when I was talking with the Lexus of Roseville parts-man on the phone, he told me that this new junction block will look the same as the one already in the vehicle (he wasn't sure where it was located) but has different internal circuitry to accomodate the tow hitch. I'll try to figure it out when it comes, but plan on going to a Toyota dealer as you suggested. Thanks for the help!

Paul K.