Technically relay-ted

By Steve Schaeber, MACS Technical Specialist

I had the opportunity recently to work on a 1990 Chrysler New Yorker Fifth Avenue that came into the MACS shop with a no-start problem. As strange as it may sound, I actually wanted to work on this car because it’s been such a long time since I’ve seen one of these, and though it’s hard to believe, according to PennDOT this classic vehicle is going to be an antique next year.

I started my diagnostics just like I would any other; turn the key to see what happens. Everything turned on, but the starter would not work, not even the ‘click’ of the solenoid. My first thought was ‘a bad starter’ when I saw the OEM label was still on it, but when I used a heavy jumper wire between B+ and the solenoid, the engine cranked over, telling me the 24-year-old starter was fine. Now I had to trace the solenoid wire back to find the problem. But before I went any further, I went online to get the schematic and make my search a little easier. This showed me that the starter solenoid is controlled by a relay mounted on the left front fender (it’s actually beside the battery in a spot not-too-easy to reach).   Probing the connector showed me there was no power reaching the relay from the ignition switch. So, I’m thinking I have to do that “lay upside down on the driver’s seat with my head under the dash” trick to work on one of those old ignition switches mounted towards the bottom of the steering column. Nope! This was the first model New Yorker where Chrysler used a new style ignition switch, located right at the lock cylinder. Whew!


So, into the driver’s seat I went, took apart the steering column covers (which are attached by security Torx screws) and I find what looks like a burned up ignition switch. So, now I think I’ve got this thing fixed. I get a new switch from my local parts house and replace it only to find that the engine still does not start.

So, now what? I trace the wires out and find that there is power at the relay, but it’s not turning on. So, before I get a new relay, I jumper the contacts to make sure the engine cranks, which it does. I took the relay cover off to see what was going on inside, and found a burned up diode. So, as it turns out, there are two problems with this car, at the same time, in the same circuit. A new relay finally gets this car starting again, and back in the hands of its proud owner.

I hope he does what he can to keep this classic going for years to come.

Author’s Note: Those of you who are regular MACS ACtion readers may find this article’s title familiar. Call it homage to my predecessor Paul, and since MACS’ mantra now includes electrical and electronics, it seems appropriate to me. Please let me know your thoughts or comments.

The Mobile Air Conditioning Society’s blog has been honored as the best business to business blog in the Automotive Aftermarket by the Automotive Communications Awards and the Car Care Council Women’s Board!

When having your mobile A/C system professionally serviced, insist on proper repair procedures and quality replacement parts. Insist on recovery and recycling so that refrigerant can be reused and not released into the atmosphere.

If you’re a service professional and not a MACS member yet, you should be, for more information.
You can E-mail us at . To locate a Mobile Air Conditioning Society member repair shop in your area. Click here to find out more about your car’s mobile A/C and engine cooling system.

The 35th annual Mobile Air Conditioning Society (MACS) Worldwide Training Conference and Trade Show, Meet me at MACS Make Connections that Matter, February 5-7, 2015 at the Caribe Royale, Orlando, FL.





About macsworldwide

Mobile Air Conditioning Society (MACS) Worldwide Founded in 1981, MACS is the leading non-profit trade association for the mobile air conditioning, heating and engine cooling system segment of the automotive aftermarket. Since 1991, MACS has assisted more than 600,000 technicians to comply with the 1990 U.S. EPA Clean Air Act requirements for certification in refrigerant recovery and recycling to protect the environment. The Mobile Air Conditioning Society (MACS) Worldwide’s mission is clear and focused--as the recognized global authority on mobile air conditioning and heat transfer industry issues.
This entry was posted in Automotive, Automotive Aftermarket, Automotive training, Uncategorized and tagged , , , , , , , . Bookmark the permalink.

One Response to Technically relay-ted

  1. Rick says:

    Sir, if I could ask, please, which type and size of torx security driver fits those steering column shroud screws. I cannot see up in the holes to tell and I don’t own any of those tools and don’t want to buy a whole set if I don’t have to. I also cannot tell if they are 5 or six point. Any help appreciated.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.