95 Dodge Ram 2500 turn signal/flasher relays

From : Annonymous

Q: the turn signals stopped working in my truck today. we check the brake light bulbs on both sides and they looked good i did have a missing back up light on the drivers side. we tried the emergency flashers and they didnt work either. on this model the two flasher relays are located in the fuse box just inside the drivers door on the side of the dash. we switched the position of the two relays and the emergency flashers worked so we could feel the clicking in the top relay and called this one the good one. the other one we called the bad one. these relays are both 552 can type relays 12v - so i had my son call two auto parts stores in town to get prices and see if they had any diagnostic tests for these relays. napa wanted $12 and autozone wanted $9 and the autozone guy told him there are no tests and there is no way to test a relay to see if it is working. i told my son to go get his dvm and i will show him how to test one. we measured 54.6 ohms on the bad one 53 ohms on the good one and 52.5 ohms on the new one and 14.43m ohms on a new long life electyronic flasher. we decided this wasnt much difference in resistance between good and bad so i cut the can off the bad one with a hack saw blade. then i hooked up a power supply and set it to 12v and touched the contact to the relay connectors and watched the metal band in the can flex over and click with a current draw of about 130ma but it was fast. so i told him there were two ways to test the relay and he accused me of using expensive equipment so we took it out and touched it to the battery and make it click again should have used a resistor in series to limit the current but didnt think of that fast enough. so off to the store we went and got the about $6.99 blazer fl552 long life ele3ctronic flasher variable load 11-15v 15a 2 pin 20-1035-4 autozone from tiger accessories group llc liconshire il 60096 - this is a solid state relay with the 14.43m ohms. we put this in and it didnt work - not sure why i figured the system in 1995 was not designed for this variable load relay but it didnt work. we returned this one and got the $3.99 552 mechanical flasher in the metal can and put this one in and it work - turn signals emergency flashers back up lights brake lights etc. so finally my question to the dodge truck/auto electric experts is if this relay worked but had a slightly higher resistance would this keep the turn signals from working and why recall the bad relay had 54.6 ohms and over 12v ohms law says it was drawing 219ma; the good one had 53 ohms and this draws 226ma and the new one was 52.5 ohms drawing 228ma. is this 7ma threshold significant in this turn signal/flasher circuit or is there something else i am missing also if you can explain how these fascinating relays work i would like to know about that also. i am sure they are some kind of thermal relay. what they look like is a blue metal shim in the center and there is a small flat wire mayber 1.5mm wide and 15mm long and 0.5mm thick that is connect across the corners of the blue metal shim this fmall flat wire is wound along its length with a copper looking small diameter wire that is connected to the two connectors. i assume the current flowing through the wire heats up the flat wire and then we have some bimetallic action between the flat wire and the blue shim and this make thes blue shim click back and forth as the wire heats up and cools down .

Replies:

From : aarcuda69062

6dfd0220-355e-4b8e-859d-38186548a13f@o4g2000pra.googlegroups.com mpate@oscintl.com wrote the turn signals stopped working in my truck today. we check the brake light bulbs on both sides and they looked good why would you only check the brake light bulbs the front turn signals are part of the turn signal and 4 way circuits also. .

From : steve lusardi

you have it about right. they are bimetallic where the current passing to the lamps passes through the heating element. this is why the flash frequency depends on the condition of the lamps. the four way flasher should not be the same at the directional lights as the load will be 4 lamps as opposed to 2. in that light they are typically not interchangable and a malfunction can be caused by anything in the circuit that changes the load current. steve the turn signals stopped working in my truck today. we check the brake light bulbs on both sides and they looked good i did have a missing back up light on the drivers side. we tried the emergency flashers and they didnt work either. on this model the two flasher relays are located in the fuse box just inside the drivers door on the side of the dash. we switched the position of the two relays and the emergency flashers worked so we could feel the clicking in the top relay and called this one the good one. the other one we called the bad one. these relays are both 552 can type relays 12v - so i had my son call two auto parts stores in town to get prices and see if they had any diagnostic tests for these relays. napa wanted $12 and autozone wanted $9 and the autozone guy told him there are no tests and there is no way to test a relay to see if it is working. i told my son to go get his dvm and i will show him how to test one. we measured 54.6 ohms on the bad one 53 ohms on the good one and 52.5 ohms on the new one and 14.43m ohms on a new long life electyronic flasher. we decided this wasnt much difference in resistance between good and bad so i cut the can off the bad one with a hack saw blade. then i hooked up a power supply and set it to 12v and touched the contact to the relay connectors and watched the metal band in the can flex over and click with a current draw of about 130ma but it was fast. so i told him there were two ways to test the relay and he accused me of using expensive equipment so we took it out and touched it to the battery and make it click again should have used a resistor in series to limit the current but didnt think of that fast enough. so off to the store we went and got the about $6.99 blazer fl552 long life ele3ctronic flasher variable load 11-15v 15a 2 pin 20-1035-4 autozone from tiger accessories group llc liconshire il 60096 - this is a solid state relay with the 14.43m ohms. we put this in and it didnt work - not sure why i figured the system in 1995 was not designed for this variable load relay but it didnt work. we returned this one and got the $3.99 552 mechanical flasher in the metal can and put this one in and it work - turn signals emergency flashers back up lights brake lights etc. so finally my question to the dodge truck/auto electric experts is if this relay worked but had a slightly higher resistance would this keep the turn signals from working and why recall the bad relay had 54.6 ohms and over 12v ohms law says it was drawing 219ma; the good one had 53 ohms and this draws 226ma and the new one was 52.5 ohms drawing 228ma. is this 7ma threshold significant in this turn signal/flasher circuit or is there something else i am missing also if you can explain how these fascinating relays work i would like to know about that also. i am sure they are some kind of thermal relay. what they look like is a blue metal shim in the center and there is a small flat wire mayber 1.5mm wide and 15mm long and 0.5mm thick that is connect across the corners of the blue metal shim this fmall flat wire is wound along its length with a copper looking small diameter wire that is connected to the two connectors. i assume the current flowing through the wire heats up the flat wire and then we have some bimetallic action between the flat wire and the blue shim and this make thes blue shim click back and forth as the wire heats up and cools down .

From : Annonymous

why would you only check the brake light bulbs the front turn signals are part of the turn signal and 4 way circuits also. good point this is why i like to use the fourm more minds and point of view. we checked the front turn signals and front emergency flashers they were working today as well. the four way flasher should not be the same at the directional lights as the load will be 4 lamps as opposed to 2. both of the circuits had the 552 flasher i dont have a schematic of the cricuits to see what they were designed with. in that light they are typically not interchangable and a malfunction can be caused by anything in the circuit that changes the load current. since all of the turn signal and flasher lights were ok i am still not sure why the one bad flasher stopped working. recall when i cut the can off and tested this flasher it still worked. to look for loads other than the bulbs i guess i could check the resistance in the wires from the flasher to the bulbs any idea what this resistance should be thanks .

From : steve lusardi

the resistance of the circuit should be very low effectively the lamps themselves. a test fixture should simply be 2 or 4 lamps in parallel plus the small indicator in the dash.. steve why would you only check the brake light bulbs the front turn signals are part of the turn signal and 4 way circuits also. good point this is why i like to use the fourm more minds and point of view. we checked the front turn signals and front emergency flashers they were working today as well. the four way flasher should not be the same at the directional lights as the load will be 4 lamps as opposed to 2. both of the circuits had the 552 flasher i dont have a schematic of the cricuits to see what they were designed with. in that light they are typically not interchangable and a malfunction can be caused by anything in the circuit that changes the load current. since all of the turn signal and flasher lights were ok i am still not sure why the one bad flasher stopped working. recall when i cut the can off and tested this flasher it still worked. to look for loads other than the bulbs i guess i could check the resistance in the wires from the flasher to the bulbs any idea what this resistance should be thanks .