hi.. i have a problem with my 1986 300e the a/c blower will only work on high speed for mabe one minute or so. it works on low speed good with no problems. the little blower relay under the hood gets really hot also i change the blower moter and the blower regular now i dont no what to do next any ideals will help thank you

Sounds like a degraded connection on the relay, remove the relay ass and check the wiring.