Bad ignition switch?

durk80 · 10-06-2017, 09:01 PM

Maybe it's my imagination, but it seems like when I am driving and experiencing surging, if I cut off the ignition, and momentarily switch it back on, it drives much better. Could this be a faulty ignition switch? I looked up typical symptoms of a failing switch and it only referred to failing lights inside the cabin, which I don't have. The car is a 88 244.

Is there any test I can do to pinpoint the problem? I do have a decent multi-meter.

TestPoint · 10-06-2017, 10:11 PM

I have had an ignition switch fail. It would pass voltage but not current which caused a long trouble shooting problem. Voltage was read at the starter but there was not enough current to engage it.

Your come and go problem may be even harder to find.

coalminer · 10-07-2017, 11:13 AM

A faulty Fuel Pump relay can cause similar symptoms.

If one (or both) of the relay contacts is burned or pitted, switching the relay off and on (via the ignition switch) can sometimes cause the relay to reset the contacts in a more conductive (read less resistive) position.

This can increase current flow and lower voltage drop to the Fuel pumps, and also the Jetronic Module.

Just a thought

It may sound strange, but I've experienced it before.

durk80 · 10-07-2017, 06:48 PM

Thank you Testpoint and Coalminer for your suggestions. I will have to test for Amps as well as Voltage to see if there are any glaring errors.

The fuel pump relay I just replaced 2 weeks ago, and I am betting that the red power wire or others from the relay to battery might be corroded from the inside under the insulation.

TestPoint · 10-07-2017, 07:52 PM

Fuel pump relays have a long history of cracking the solder joint between the relay external contacts and the circuit board inside. Some cracks are just not visible. Remove the cover and flow the solder connection.

To old for this · 10-08-2017, 03:59 PM

Indications that the switch is failing is you know the radio or the a/c fan was on when you shut the car off. Upon restart they were off. If you wiggle the key they come on. Switch going.

10-06-2017, 09:01 PM	#1
durk80 Board Member Join Date: Nov 2015 Location: Athens, GA	Bad ignition switch? Maybe it's my imagination, but it seems like when I am driving and experiencing surging, if I cut off the ignition, and momentarily switch it back on, it drives much better. Could this be a faulty ignition switch? I looked up typical symptoms of a failing switch and it only referred to failing lights inside the cabin, which I don't have. The car is a 88 244. Is there any test I can do to pinpoint the problem? I do have a decent multi-meter.

10-06-2017, 10:11 PM	#2
TestPoint Board Member Join Date: Jul 2009 Location: Ellijay	I have had an ignition switch fail. It would pass voltage but not current which caused a long trouble shooting problem. Voltage was read at the starter but there was not enough current to engage it. Your come and go problem may be even harder to find. __________________ 1982 Volvo 245 with a Ford 302 V8 Ford V8 Conversion Manual - http://forums.turbobricks.com/showthread.php?t=250257 Bertone Restoration - http://forums.turbobricks.com/showthread.php?t=256460

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10-07-2017, 11:13 AM	#3
coalminer Board Member Join Date: Mar 2013 Location: North Georgia Mountains	A faulty Fuel Pump relay can cause similar symptoms. If one (or both) of the relay contacts is burned or pitted, switching the relay off and on (via the ignition switch) can sometimes cause the relay to reset the contacts in a more conductive (read less resistive) position. This can increase current flow and lower voltage drop to the Fuel pumps, and also the Jetronic Module. Just a thought It may sound strange, but I've experienced it before.

10-07-2017, 06:48 PM	#4
durk80 Board Member Join Date: Nov 2015 Location: Athens, GA	Thank you Testpoint and Coalminer for your suggestions. I will have to test for Amps as well as Voltage to see if there are any glaring errors. The fuel pump relay I just replaced 2 weeks ago, and I am betting that the red power wire or others from the relay to battery might be corroded from the inside under the insulation.

10-07-2017, 07:52 PM	#5
TestPoint Board Member Join Date: Jul 2009 Location: Ellijay	Fuel pump relays have a long history of cracking the solder joint between the relay external contacts and the circuit board inside. Some cracks are just not visible. Remove the cover and flow the solder connection.

10-08-2017, 03:59 PM	#6
To old for this Board Member Join Date: Sep 2016 Location: Texas Panhandle	Indications that the switch is failing is you know the radio or the a/c fan was on when you shut the car off. Upon restart they were off. If you wiggle the key they come on. Switch going.