Weird problem: Car almost stalls out when using turn signal on highway

My friend has a 1986 Ford Country Squire Station Wagon. I haven't had a chance to look at it yet but wanted to see if anyone had any ideas on this crazy problem he told me about. Intermittently, his car will run very rough and almost stall out when he uses his turning signal. He says it only happens when cruising down the highway and he doesn't even need to change lanes before car starts bogging out as soon as he puts turning signal on. I am baffled on how the turning signal could be related to the vehicle almost stalling. Any ideas to get me started in this would be greatly appreciated. Thanks!

 

Even weirder is asking for information before an introduction.
About the blinker problem I have never heard such a thing. Half the little old ladies in Florida where we moved from drive with the left blinker on.
Which signal causes the problem and what happens when the 4-way flashers are on?


See your authorized Ford dealer immediately. Your friend needs his blinker fluid changed.

 

Haha. Sorry about the lack of introduction. I was anxious to help my friend out. I've never owned a wagon but have had many cars and trucks which I always tried to do all my own repairs. I'm no mechanic but have a decent knowledge of car repairs. I stumbled on this site and it seems like there is a good group of people on here and ones with jokes I'll add a little info about myself to my profile shortly.

I've never heard of it either and asked him numerous times because I told him he is crazy. It happens only at high speeds and when either left or right blinker or turned on. We're not sure if it occurs when the 4-way flashers are on. He's going to try tomorrow and let me know.

Honestly, he may actually believe me if I tell him he needs his blinker fluid changed. He's an engineer but doesn't know squat about cars.

 

Bad ground or short in the column maybe

 

Take the shrouds off the column. Verify all the components of the column are tightened down, verify all the components attached to the column are tightened down, then verify all the electrical pigtails are snug in their sockets. My padawan mechanic Steven's '87 Grand Marq would go crazy when turning on the wipers, either turn signal or making a fast, severe turn. Turns out the column fasteners were loosey goosey, so any movement would cause all the components to shift, pulling on the ignition electrical switch actuator, and sliding the contacts off of the ON position, stalling it. Check that column first. It's the only way a mechanical motion could affect an electrical operation: by mechanically cutting the power. Then, if that's all good, check the charging system and battery. If his car's on the edge of complete failure, any new load switched on could pull system voltage below ignition, computer or fuel pump minimum voltage. I've seen FI cars begin to falter because the voltage to the pump, shut off because the voltage needed to keep the power relay latched was lacking, and on carbed cars, the alternator quit working, and the battery drains below the ignition's minimum voltage, so the car just stops running. Ask me, the diagnostic tech, about getting stranded on a hot Summer day......

 

Unbelievably, the "ALT" light never came on!