Jump to content
griffin3

Dim TOAD lights through diode harness

Recommended Posts

I am pulling a 2007 Chevy Avalanche behind my 1994 Bluebird Wanderlodge.
I am using the Roadmaster kit made for the Chevy Avalanche that has diodes and connects to the tail lights through the harness connections.

The problem that I am having is that the tail lights through the harness are very dim, no where near as bright as the lights when the truck is providing the power to the lights.

  • I tested the 7 pin to 6 pin tow cable and it tests good with little resistance.
  • I checked the voltage at the 6 pin end and I am getting 12 volts on each of the signal wires for the tail lights, turn signals, and brake lights. 
  • My RV does not have a tail light converter.
  • I converter the tail lights on the RV to LED.

Is there a way to check that the diodes are not eating up to much power? 
Should I be running a tail light converter to push more power to the TOAD?

Share this post


Link to post
Share on other sites

You will lose about 1/2 volt through a diode.  Its not comparable to judge the brightness from the truck when its running to when you are powering the lights from the motorhome.  You have 13.5 to 14.3 volts from the truck vs the same voltage from the motorhome but the 35 to 45 feet of number 16 or 18 gauge wire drops the voltage.

Share this post


Link to post
Share on other sites

Have you confirmed a good ground connection? Not sure if you have a separate ground wire in the harness or not. I had a trailer once which used the ball hitch to make the  ground connection, and it created a problem like you're describing. If you do have a separate ground wire in the harness, verify that the connection to the chassis is clean and tight on both the coach and the toad.

Share this post


Link to post
Share on other sites

Measure the voltage with everything connected if you can.   Perhaps across the bulb(s) themselves.  

Measuring 12 volts (or 13 or ??) at the connector without the lights connected is meaningless.  A high resistance connection (or ground) will still pass the full voltage when no current is being drawn. 

I like to use a 12 volt trouble light to probe the wires https://www.amazon.com/Voltage-Continuity-Current-Tester-Indicator/dp/B01BGZ9XRS/ref=sr_1_5?keywords=12+volt+trouble+light&qid=1572750908&sr=8-5  Try it across the battery first to get an idea of how bright it should be.  If there is a bad connection somewhere the light will be dim.

If you use one of these be sure to connect the ground clip to the ground lead in the plug to verify it is tied to a good ground.

Lenp

Share this post


Link to post
Share on other sites

griffn3,

Welcome to the Forum.

A quick way to check the ground to see if you have good contact would be to hook up as you always do. Then take your jumper cable and connect the chassis of the coach to the chassis of the toad. If your lights are better then  check the ground on the coach.

Herman 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...