|
Well having lots of experience testing/replacing relays on F-4E/G's to 8-lamp systems on school buses.
1. You need a good ground for the coil
2. You need good volt's & amp's (no corroded wires connectors etc) for both signal and switched power
3. Measure the relay with an Ohm meter across the switched contacts. You will have to look at the pin out to see if the open and closed positions are used. You should measure less than 1 or 2 Ohms resistance.
4. A relay can be thought of as a set of points (sorta realy slow ones) both have contact surfaces that can pit corrode etc which increase resistance drop volatage and up the Amps.
5. If you have a problem and a new one corrects it..... take a hammer and smoosh the old one. And yes new ones can be bad from the factory.
6. If you suspect wiring check it point to point for resistance with components on both ends disconected.
So it could be anything from the signal source (keyed power, ign switch etc) wiring etc. Also check connectors for corrosion on the pin side AND where the wires enter the connector.
Also when checking the connectors don't use a probe larger than the female connector.
Well thats more than what I thought I was going to say.
Hope it helps
Chris
|