Caravan turn signals dont work at all

Check the main fuse that comes off the battery.

This may help, but check all the fuses

https://www.justanswer.com/buick/61gr1-buick-century-no-dash-lights-tail-lights.html

It is a known issue!

https://www.google.com/search?q=1991+Buick+ultra+no+dash+lights%2C+tail+lights%2C+or+turn+signals.

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check both fuse boxes,, One is under the dash inside the van, the other is under the hood,,

when u press the hazards do they flash? let me know if not its the blinker relay.

Check fuse # 12 and 14 at the power distribution center (fuse box) in the engine compartment near the battery. If both fuses test good, the the more likely cause of your problem is either the turn signal / hazard switch or the Combination Flasher / Daytime Running Light module. This module is located on the junction block, behind the left side of the dash.

The switch can be tested by accessing the wires at the base of the steering column.
Left turn signal = Light Blue / White
Right turn signal = Light Blue / Yellow
Hazard flasher = Dark Blue / Pink

These wire should show ground when the switch is actuated in its respective positions. If ground is not present when the switch is actuated, check also the black wire at the switch. This wire should show ground at all times. If you do not get ground on this wire than there is an open in this wire. Repair or re-grounding this wire should solve your problem. If the switch test good than the Combo Flasher / DRL module will need to be replaced.

I had this problem right after I had my battery replaced. Not believing in coincidences, I took it to a friend who checked the battery and cables. Looking at the battery cables, there are small wires that attach to a thicker cable which go to the clamp that attaches to the battery terminal. The battery installer cleaned the corrosion off the clamp and the battery cable, but the connection between the small wires and the larger cable still had corrosion between them. My friend cleaned off this area, and the problem is gone.

Access your fuse box and check the fuse labled- rear tail lgts,turn sgns, that fuse is blown, replace the fuse with the same value fuse, while your under there, on the fuse box or next to it you'll find 2 round plug in components, about the size of a Marshmellow, one of these is your flasher unit and the other is for your turn signals, replace both of these, even though one may work, it's just good sense to replace both, that shoud fix your rear lighting problem. good luck.....

sounds like you need a combo flasher assembly..located in fuse block inside vehicle under steering column..there may be a plastic cover under dash you have to remove to see fuse block..large black relay that plugs into fuse block..if you pick up a new one,you will see what it looks like..available at dodge dealer..combo flasher or drl/signal relay

check in the fuse box on the drivers side under the hood. Check for "display lights" or "Dash" maybe even under "ACC". For the signals check for "turn signals" or "Lights" Should be 15 and 20 amp fuses. Replace those and everything should work. If you cannot find the signals and other things in the fuse box when checking the diagram, then look at all the 15 and 20amp fuses by pulling them out with needle nose plyers. Whichever fuses look cracked, snapped or burnt should be replaced. You could pick up a pack of fuses at a gas station or autoparts store for about $2.99

Did all these problems happen all at one time?? If so you may have a bad body ground. Try running a electrical wire from the (-) negative side of the battery to the body and see if this works. Be sure this wire is to a place with no paint as low voltage electricity will not flow through paint.
A). If not try replacing the turn signal flasher for the turn signal problem. This is usually the culprit and it's easiest and cheapest to replace. The turn signal flasher will be found under the driver side dash next to the hazard flasher. Turn the hazard flasher one to locate it. If you want try swapping the turn signal flasher with the hazard flasher to see if this fixes it. They are the same style flasher.
If this doesn't work you may a faulty turn signal switch or some wiring issues.
B). It could as simple as the head lights bulbs need to be replaced, it's rare but I have seen when both bulbs blew at or near the same time. If your able check the voltage at the head sockets.
C). Could be a bad blower motor or switch. I'm not sure if these models have a resistor block or not. The resister block controls the electrical current going to blower motor which controls the speed of the blower fan.

on the turn signal check the fuse block in the passenger compartment, it will be a square relay on the right hand side, try to adjust the relay with the turn signal on,