bench testing a hazard switch

[fordman]

i have been asked to bench test a hazard switch from a 70-72. i know atleast two of these were working when i pulled them. but i want to get it on video so i can prove it. from the 69 diagrams i have here. the power comes into the hazard switch can from the fuse box. and then over to the hazard switch. from there out to the light. the light i am using is a 1156 bulb in a backup light socket. so it is a single element bulb. will the light blink using this bulb? do i have to bring a second power sourse to it ? the column usually brings power over from wire 810 to the swithc. i am thinking it is the main power source and not the hazard can power. what am i doing am i doing it right. i am providing power to the correct pole of the hazard switch i know that much

[fordman]

i need to ground the hazard swithc and the tail light houisng is that what im doing wrong?

[fordman]

well i grounded it and it worked when i bypassed the flasher can. so i know its good. but why would i have two bad flahser cans in a row? mayeb im not hooking it up right. wire 810 comes from the turn siganl switch. in a truck. and is basically a round abotu for both blinker terminals in the swithc. so it cant really be that. 810 is just used to make both rears flash . instead of running two wires for the rear they cross inside of the turn signal switch so that cant be the problem. maybe the flahser can needs to have all four lights hooked up to work? no that cant be it either. it has to be bad flasher cans. what do you think.

[70_F100]

If I remember correctly, the hazard switch has only two terminals.

Correct?

[fordman]

it has 4. one for power in the other for both rear lights from the turn signal switch and each front has an individual wire.

[70_F100]

Figure out which one is power.

Using an ohmmeter, put one of the leads on the power terminal.

With the switch in the "off" position, there should not be any resistance (the meter should not move) when you touch the other three.

With the switch in the "on" position, you should see the meter go full scale when you touch the other three leads.

[fordman]

i can get power through when the switch is turn one. from the power side to all of the other three terminals. and when its off i get nothing. i was trying to get a blinking light when it was turned one. but i could get it to flash with hte flasher can hooked into the system. i even tried the flahser in there backwards so the power went through it from the other side of the can but that didnt work either. maybe tonight i will put it through a column also and se if i can get the flasher can to work. i shouldnt need to i though.

[stephen44]

so my memory of flasher cans is that they only work when the correct resistance is there - they use a bimetallic strip - at least the old ones i saw did - meaning hat it may not work unless you have the correct number of bulbs connected.

Think about when a bulb blows - the remaining ones blink twice as fast ?


this is probably rubbish - but it may help ????????? - Stephen

[70_F100]

Fordman, if you've got continuity like you say, then the switch is good. It's only purpose is to make a connection, since it's nothing but an "on/off" switch.

All of the flashing takes place in the flasher itself. On a light-duty flasher, the action is caused, as stated, by a bi-metal spring and resistance from the lights. I would try either a heavy-duty flasher or one of the newer solid state units.

I haven't had a chance to check the wiring diagram, but after thinking about it, something doesn't sound exactly right about your description of the circuit. I would think that the circuit would include a power lead, the flasher and somehow be wired through the turn signal switch, but I could be wrong.

I just can't see how the circuit would function properly without incorporating those components. Just going from the switch to the lights, like you described, would give constant power to the lights.

Does the power lead come from the flasher? That would be a possibility. The power coming into the flasher could be constant "on" and when the emergency flasher switch is turned on, that would complete the circuit to the lights.

[fordman]

power is suppose to go to the flasher can from the fuse box. and then to the swithc. three other wires go to both front turn signals on seperate wires. and the last wire goes into the turn signal switch from the flaher switch and then back out of the rear lights. that is how i had it hooked up last night except i didnt include the turn signal swithc in the wiring. so i basically eliminated the rear lights is all i did when i whad it hooked up. i may have to hook up all the lights to see if i can make it work. i just thought it would be better to show it flashing a light. to prove to a buyer that it defently worked 100%. i will mess with it again tonight.

[70_F100]

You can just hook lights to each of the output terminals to show it working.

You don't have to run it through the T/S switch.

[fordman]

i got it. it was a bad flasher can. as i had thought in the beginning.i will post a video just for fun of it. ahhhh. what an big head i have now. if i can get it emailed to my computer i will post it.

[fordman]

http://www.youtube.com/watch?v=PEloWVL7uIc

[ToughOldFord]

Desktop strobe light, groovy man...