I bought a Kenwood MP-238 today since I'm tired of not having music to listen to when I drive the Mustang. The previous owner had already hacked up the dash so I went the modern route. I had to purchase some speakers as well. I get the stuff home and get to work. This is the second radio install I've done and it's fairly simple.

I track down all the wires, get them connected and heatshrinked. I plug in the head unit, reconnect the battery, turn the key to accessory...and nothing. The head unit stays dark. I start the car...nothing. Triple check my wiring, from the connector I get approximately 12v from the battery to the proper wire. I get about the same voltage from the ignition wire when I turn the key and I'm verifying all of this off the same ground wire used by the radio.

What are the odds I purchased a bad head unit? The fuse in the deck isn't blown. I figure the fuses in the car wouldn't be blown if I'm getting the proper voltage.

Mom's got the same deck in her Astro (the first one I installed) so I'm going to drag it over to my parent's house tomorrow after work and put this unit in the Astro to see if it works. If it does is there anything to check beyond making sure all the wires are properly connected?

 

nope..sounds like you've go it covered

 

Push power on the radio.....

 

+1 Did your install also included a lot of this?? [sm=alcoholic.gif]

Just kidding.?

Try installing a second ground wire to a unpainted surface somewhere in the dash, Do Not remove the current ground wire you have, just run a jumper wire over to a new ground spot (after 40 years the old radio ground may have lost contact with the body).
And it sounds like you have done most of the trouble shooting correctly. If the second ground wire doesn't help then it would be great to be able to plug it directly into your mother's car. as long as it is Kenwood to Kenwood. That will help alot.
after a series of trouble shooting thta doesn't work it may help to start over from scratch. uninstall everything and try it again. it could be as stupid as a loose wire/connector,insulation missing somewhere.
good luck this can be very frustrating. [sm=headbang.gif]

 

No-one will ever classify me as an audiophile. I can barely figure out how to operate most modern head units, nevermind install them.... but one thing I always do prior to installing any radio is bring it down to the local car audio installation business and have the technician connect it up to his test bench.

There is never a charge for this service and it sure helps to know that not only is the head unit serviceable, but more often than not the technician will quickly run through each wire and where it should be connected.

Maybe your local shop offers the same service?

Good Luck,
Dave

 

I know with my head unit I had to plug it into the 12v yellow wire and a constant accesory power source for it to turn on.

 

Sounds like you have checked most of the important things. I would add two other things to the list.

- Check voltage at the fuse in the back of the radio using the radio chassis as your ground. This will confirm power at the unit using the ground supplied to the radio. If this does not provide at least 12V you should check your connections again.

- Try to disconnect the speakers at the back of the radio. If there is an issue with a speaker or speaker wires, the radio may not turn on to protect itself from damage.

If all else fails, take the radio back to the store and have them bench check the radio.

 

If you have voltage across from ground to 12V+ and from ground to 12V switched your power wiring is fine and any fuses up to the point where you tested are also good.

As stated, check the resistance of your speaker connections (they should be around 4 ohms).

Make sure all your connections are tight!!!

 

Found the issue The radio worked in my mom's Astro so I had to go recheck every wire.

I was testing on the bolt for my ground but not the ground wire itself. I crawled under my dash (not an easy feet for my bulky self) and saw my ground wire hanging on to the bolt with just a few pieces of copper thread. I cut, cleaned, and regrounded and now my radio works and sounds AWESOME

Thanks for the ideas everyone, I'll keep them in mind if I run into any future trouble