1972 Duster Build with my Daughter
sorry. The dryer I bought did not have a sight glass.
Hmm, curious. I'm guessing it isn't an NOS unit? Just out of curiosity, are the drier fittings o-ring or flare?
@MaxPF so hot day and went for a drive. The clutch started slipping at stop... got home and looked at the pressures... they were high so I removed some R134A and now have about the 80% of the R12 value.
What were the pressures before and after you removed refrigerant?
Also the drop across the switches seems to also be part of the problem. I jumped straight to the battery and it engaged hard. Wired in a relay as a test and so far with the right level of freon and a full battery voltage on the coil it seems like it is working great. If this solves it I will wire in the relay a bit more stealthy and much more professionally.
Good to hear! Yeah, voltage drops caused by multiple switches and small wiring are a common cause of clutch slippage. Again, make sure you are using 14ga. wire for all the power runs between the battery, relay, and coil. Make sure you're using a high quality 30A or 40A relay, preferably in a sealed socket. Don't forget a solid ground as well. And make sure there is a flyback diode reverse-biased across the coil. Also, don't forget to fuse the power lead at the battery. You don't want a short causing an under-hood fire!
Here's a complete 40A relay and sealed socket kit:
Home » Shop » Relays / Fuses » Tyco MCP 6.3 (630) High Current Sealed Relay Kit SPDT 40 AMP
This is a new kit. It is actually cheaper than the Delphi (now Aptiv) 30A relay kit. The kit comes with a high quality relay, not cheap junk. Ive used it to run electric fans and blower motors, and havent had one die yet. Again, make sure you have a 3A flyback diode installed across the coil terminals, reverse-biased, to protect the relay contacts from arcing caused by the energy stored in the coil's magnetic field.
A nice sealed fuse holder for ATO (blade type) fuses:
Home » Shop » Relays / Fuses » GM / Delphi - Sealed Fuse ATO Holder Kit - ( 18 - 14 gauge )
Mount the fuse holder as closely as possible to the battery terminal, with as short of a wire as possible on the battery side of the fuse holder. A 20A fuse should be sufficient for the clutch coil circuit.
FWIW, I've bought connectors from Ballenger many times with no issues. They're not the cheapest place, but they're not out of line either, and the convenience of their kits makes it worth the few extra bucks if you're buying one-sees or two-sees.
