[39chevy]

I can't get my wipers to run off my vacuum port! I didn't do anything different, ran from the carbs vac port direct to my wiper connection, they won't turn on! What is wrong? 2nd question how hard is it to change from vacuum to electric, I'm not sure if I will or not just curious,maybe, Dana

[matt167]

Your wiper motors need rebuilt or a leaky vac hose, they should go at around 10 HG. Try a vacume can, if that works, just mount it out of site, if not www.chevsofthe40s.com has new vac wiper motors, they require a core of your old 1. If your staying 6 volt, you arn't gonna convert to electric wipers, if you are going 12V, there are conversion kits. vacume wipers are not great, but I guess they work, just they slow down and speed up with the engine RPM and arn't fast at all, a vac can is actully advisable to keep the vacume the same through the diffrent RPM's.

[docvette]

Doc here,

Try running a line DIRECT from a vacuum port..and see if they run, If not the diaphragm is probably shot..replace it.

Electrics should be available for you car from places like OPG or Hemmings, or year one...just do a little web surfing..

If it does work, you might want to install a vacuum canister from a late model car with an input check valve to avoid "loss of wipers" on throttle..

Doc

[39chevy]

I'm thinking probably bad diafragm, your right doc how hard of a job to change?

[docvette]

Doc here,


Diaphram ? or Electric?

Diaphram is easy, half the motor (or motor top..) carefully (springs and things..), pull it out and install the new one..check to see if it requires a sealer at all..

Electric..
Not bad at all actually, If you can get direct electric replacements to fit in he old locations mechanically...(I'm assuming above the sun viser?)

Just get a wire from the fuse center that is NOT being used, fuse it for recommended amperage..

Run that to the switch (usually also provided in a kit, cuz of speed control) or if not, One speed, but under 25 amps to a capable switch then the On/Off side must be fished up the windshield post (as well as any other speed wires if used)

Make sure you have a good ground, add one to your fish if room permits..and you pretty much have it..use star washers and burnish paint..

If the wipers draw more than 25 amps or you cant find a proper load bearing switch, Then you must use a relay. wire ANY switch from the vehicle you so designate, to the coil of a relay, the other side of the coil to ground..Then wire the Center wiper (C.W. or movable contact) to the wiper motor.. The Normally Open N.O. contact to a proper fuse / link then to switched power..and you will be fine..

Doc