Robkei

Greetings All,

I posted this in the Roadster section and haven't gotten much response. So, I thought I would give it a post here. Being a Newb, I hope I am not cluttering up the Forum.

I recently had my 560SL's A/C system converted from R12 to R134. I had heat before the conversion, now none.

My mechanic did the following: "First swap climate control unit with known good unit, no heat. Inspect newly installed Mono valve, ok. Swap temperature control unit with known good unit, no heat. Electrical testing of signal to mono valve and aux water pump at 12.8volts from 0 volts, good. Checked inlet heater hose temp at 135 deg and the outlet is approx. 70 deg, should be closer to inlet hose temp. The signal to aux pump can be manipulated to obtain heat."

Any suggestions?

Thanks much,
Rob

GLENN S.

Converting over should not affect the heat. Sounds like the heater core is clogged

Robkei

Would that be effected by manipulating the electrical connections next to the mono valve assembly? Manipulating those wires does produce heat.

GLENN S.

Could have a broken- frayed wire in the harness