Toad turn signal lights don't blink when tail lights are on.

[Wiz]

I've have a 2000 Coachmen Class C motor home on a Ford E-450 cutaway chassis. I tow a 2004 Honda CRV behind it with a Blue OX towbar. I have a problem with the extra lights on the toad. If the coach's tail lights are on, the turn signal lights barely blink, the just stay bright with a very slight dimming each cycle instead of turning off and on. I have the same problem whether I use magnetic tow lights or additional lights I wired into the CRV tail lights. If the running lights/tail lights are off, the lights blink correctly. I've replaced the blinker relay with a heavy duty one with no difference. Looking for ideas how to isolate and fix the problem.
Thanks!

[Wiz]

Thanks! I will check the ground wire today. Since the chassis is the ground, doesn't it just need a good connection to the frame?

[Dog_Folks]

99% of the time problems like this are caused by weak or bad ground.

[Golden_HVAC]

I would also check the ground wire. You might try some jumper cables first, and see if that makes it work right.

Fred.

[MEXICOWANDERER]

Sounds like the ground wire return is screaming for attention. Turn signal elements consume 3 times the power of tail lights.

Hook everything up. Then use a volt meter. Set to Volts. Connect the positive lead to the tow vehicle the negative to the toad. What do you see?