Signal Light Issue

[3Rovers]

right side blinks fast which usually means bulb issue. Bulb checks out ok and all other light work. 4 way flasher works except the front right signal in question.

Question: can this be a flasher unit issue with just one corner not flashing?

[Red90]

If one light is out that side will blink fast.

[3Rovers]

bulb checks out by switching and  fitting to other side.
May be corroded wire to the fixture? No corrosion inside bulb holder.
Or flasher relay maybe?

[Red90]

Not the relay. It sends out power through one wire to everything. Need to check the wiring with a meter. What vehicle are we discussing?

Start buy checking for both power and ground at the lamp. Then follow the bad one of the two to each connector.

[3Rovers]

This is on my 1989 D90.

[Red90]

I would look first at the bullet connectors where the light joins the loom. These tend to get corroded.