• To ALL forum users - As of late I have been getting quite a few private messages with questions about build ups here on the forum, or tech questions about your personal project. While I appreciate the interest, sending me a private message about these topics distracts from, and undermines the purpose of having a forum here. During the day I wear many hats as a small business owner-operator and I work tirelessly to provide the absolute best service possible to you, our valued customer. When I created this forum I rounded up some of the best minds I knew so that any tech question you might have could be asked and answered by either myself or one of my highly experienced moderators, this way the next time this same question is asked the answer can be easily found and utilized by the next IH enthusiast having the same question. This allows me the freedom to run the day to day operations of the business and minimize the impact to shipments and shop activities that these distractions can cause. It is of the up most importance for me to complete the daily tasks in order to best take care of you our customer, all the while providing you a forum to get the level advice and input you have come to expect and deserve from the premier IH shop in the country.

    So with that I ask that anyone with a question about one of our build ups or a general tech question to please use the forum as it was intended. I am absolutely available by telephone to answer your questions as well but at times may direct you back to our website to better field your question or questions. Most other private messages I will be glad to answer for you.

    Thank you for your understanding.

    Jeff Ismail

Exterior Lights Help


New member
1974 Scout II
All running lights work properly.
Right brake lights work properly.
Right blinker works properly.
Front left blinker stays on solid.
Rear left blinker does not come on.
Hazards - front left and right work properly.
Hazards - rear right works properly.
Summary - Left rear brake, hazard, blinker does not function. Front left blinker does not function.

I've taken everything apart and can not figure out the problem. I assume there's a bad ground somewhere, but where? Please help.


Do you have an incandescent probe with alligator ground clip? If not, get one and use it to check for power in the socket contacts of the left rear light housing. If no power there, then check for power at the rear gang connector on the right hand side near the end of the frame.


New member
No power to socket. If I am looking correctly, the wiring goes from drivers side to passenger side tail light, and then it looks to go towards firewall? Is there a quick easy way to check at the firewall to see if the problem is way up there?


It's helpful to always think of where the power is coming from as being the origin point in relation to the fixture trying to be lit, which is the destination. So while you're technically correct, when you consider how the power flows, you actually have it backwards. The flow of current to the rear tail lights is as follows:
Headlight switch to firewall bulkhead connector, then traveling down the right hand frame channel to a gang connector at the right rear of the vehicle. From there it splits out to the light housings on either side. Any major junction point has the potential to be the break in power flow. That most certainly includes the gang connector at the rear and the firewall bulkhead connector. Both locations should be checked for the presence of power when the HL switch is activated.
Also check the flat connector that comes out of the steering column. The rear brake lights and blinkers go through this connector. Sometimes things get corroded. And sometimes the actual wire crimps migrate out of the connector. Disconnect the two halves and inspect for corrosion. I usually WD40 the metal parts and scrub with a toothbrush. Rinse with more WD, then blow it out with compressed air. Same treatment at the bulkhead connectors at the fire wall. Its surprising at how resistive a decent looking contact can be. Never hurts to give them a scrub.
I had a crazy problem where some cheap LED tail lights would short my tail and brake lights together. It would cause my turn signals to work erratically in one direction when my headlights were on. Otherwise they were okay. Replacing the bulb with a regular incandescent fixed it.