Help requested: 1974 SLC won't start
 

Hi all--

So I bought a great-looking 1974 SLC this past Saturday from an auction dealer, and--of course--it wouldn't start this morning. I'm in San Francisco, and it's fairly cold outside today for SF...in the low 50's.

The dealer mentioned that the car hadn't been run that much lately, and that this might happen because of that.

When I tried to start the car this morning, it didn't make the clicking sound that I've seen drained-battery cars make. However, the battery light and the light next to it -- what I think is the check engine light -- lit up, but that's about it. The car stereo was on when I started the car, and worked okay. It still works. The power windows worked for a second, but quickly stopped. (Thankfully, I only pulled them down a little!)

What's really weird is that I wasn't able to jump-start the car. I ran cables from my Subaru Outback to the positive-negative bolts with no positive effect. I checked the cables to make sure they're carrying a charge, and they are.

I don't know a whole lot about cars, but I know how to jump start, which is what has me wondering what the problem could be. Unless jump-starting an older Mercedes is somehow different than a normal jump?

As for what the root of the problem could be, the car has an after-market amplifier in the trunk. Could this somehow be causing the excessive power drain?

Or is my battery just flat-out dead?

Any recommendations? I'd appreciate it...I'll probably take it to a mechanic in SF (any recommendations for that too?), but I'd like to get an idea of what's going on first.

george

Hi,

Always try the easy/cheap things first. It may well be a dead battery, but the fact that you couldn't jump start means that there may be a bad earth between the battery negative post and the car body. Follow the lead from the negative post to where it bolts to the car. If it is either rusty or covered in a chalky white deposit then you probably have a bad earth. remove the bolt and clean the terminal and where it attaches with a stiff wire brush before replacing and re-tightening. Also clean the posts on the battery and the terminals that attach to them.

If after doing this you are able to jump start it then you will need to get the battery condition checked. If you can't start it then the next level of fault finding starts. Let us know how you get on. Good Luck

--
bobw
1983 380SL
1991 BMW 735iSE

Thanks for the advice Bob--

A guy on the Vintage forum suggested that the problem might be the neutral safety switch, and that I should try starting the car in Neutral. Amazingly, that worked.

Now all I need to do is replace that switch, I guess.

Thanks for the help!

george

<<The power windows worked for a second, but quickly stopped.>>

The functioning of the power windows is unrelated to the neutral start. Are your windows working now?

Yep, they're working fine now. Actually, all is working fine now.

It even starts in park again...

george