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Ac drawing in a lot of amperage

Started by Sa_nyo, 12 May 2023, 11:08 PM

Sa_nyo

So little bit of information, when driving with the ac and lights on sometimes the tachometer starts going crazy when idle. Then one time when waiting at a light everything electronically shut off except the engine, and so messed with the idle and raised it cause I had thought maybe I was too low on rpm and the alternator wasn't getting enough energy, so the battery wasn't charging. But then found out that when the ac is on its drawing a lot of amperage, and now I'm wondering if the blower motor needs to be replaced or if the blower motor resistor needs to be replaced. If so are there any after market replacements?

daantjie

Sorry to be pedantic but may I suggest some punctuation in your post.  It makes it very difficult to follow what you are asking. And no I am not an old Boomer  ;D
Daniel
1977 450 SEL 6.9 - Astralsilber

Sa_nyo

Quote from: daantjie on 13 May 2023, 11:43 AMSorry to be pedantic but may I suggest some punctuation in your post.  It makes it very difficult to follow what you are asking. And no I am not an old Boomer  ;D
edited it, sorry about that not the best when it comes to punctuation.

daantjie

When you are experiencing this condition are you getting the battery warning light on the dash come on?

As a side note there should be a vacuum advance on the distributor which gives you "idle up" when you turn the AC on.  It is controlled by a vacuum switching valve at the firewall.  Might be worth checking all the vacuum connections and the switch.
Daniel
1977 450 SEL 6.9 - Astralsilber

rumb

You might need new brushes in your alternator.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS
'21 E450 Cabrio

Sa_nyo

Hello everyone so apologies for no response I was waiting to see how everything would play out after adjusting the idle. But I am still having problems, pretty sure it might be the blower motor going bad cause I only have the losing power issue when it is on. Plus when it is on my lights go really dim and the tachometer drops to 5000 rpm, but when I turn it off lights go bright and the tachometer jumps back to where it should be. Also battery light does not turn on at all when this is happening. Here is a video to show what's happening.