Klima Cost .... Aaaccckkkk!
 

My 350 SDL's intermittent tach and a/c problem just got worse ... I checked the speed sensor pickup at the bell housing - it had a few metallic flakes on it, but looked good otherwise - did not fix problem. Checked every cable connector and could find nothing but great connections ... checked all fuses (although I don't think a single fuse, with no other failures, would cause the a/c and tac to both fail) ... nothing changed problem.

Finally, looked at Klima connections (part number 0035452605) ... one of the terminals was a little dark ... started and ran engine ... still no tach or a/c .... smacked the Klima with a wrench and got all functions back normal. Touched Klima again and lost 'em all.

Guess I will have to replace the relay ... initial part search turns up ludicrous price of $200!! Any other options?

Many relays are pretty simple once you figure out how to get them apart... and usually just involve cleaning and renewing ( filing or maybe putting silver solder on it ) the contact surface....
So AFTER you locate a good replacement,but before you buy it, you might try taking it apart to try fixing it... that does seem like way too much money for it....
If you do take it apart,, take pics for the FAQ pages.... :cool:

I recall paying something like 85 bucks for a new Klima relay to fit my '87 TD. May not be the same part though...

Tried to post the photo, but it was too large.

Took relay apart - first removed th thin bead of silicon on the bottom edge and then gently pried the cover from the base by inserting very small straight slot screwdriver first on one side then the other until the detent popped out of the slot.

Looked very clean, could find no obvious solder issues ... I stupidly never learned much about troubleshooting electronics ... there were two relays inside. The first, on the left of the board, had room for two sets of contacts, but only the right side was populated (left portion was simply empty). The right set was two contacts mounted in one spring relay mechanism.

I cleaned the contacts with alcohol soaked into a small piece of paper (same process as contact points for ignition). Popped back together, sealed with silicon using a putty knife across the seam. Mounted back into connection plate. Seems to work OK for now.

If indeed the points are getting dirty and that causes the intermittent problem I was having, or if this is primary failure mechanism - i.e. the contact points get dirty or pitted, it is a very simple fix. Start to finish, about 10 minutes, most of which was simply examining the electronics.

Fingers crossed ....