Relay part numbers?

[Warren Lovell]

Does anyone have the relay part numbers for Gen 1 and Gen 2?

This is for an ongoing problem I'm having and am starting with the least expensive stuff first.

thanks for all your help!!!

warren

 

[mr.travo]

Stupid question....

What does the relay do and what are some give-a-ways when they go inop?

Sorry for the dumb question, just want to gain the knowledge. My buddies M1008 is turning into a FORD (Fix Or Repair Daily) and I would like to be able to help him out with his issues.

 

[ida34]

There is only a relay for Gen 2 to provide a 24 volt trigger when the ignition is on. The other relays next to it are for the starter and the voltage gauge.

AC-40 It is a standard GM relay and I think they use it for a horn relay. The number I just gave is for the starter relay and I think the other two relays are the same.

 

[Warthog]

The lights in the instrument cluster are part of the Gen1 and Gen2 circuits. If they are bad the alternators will not work.

Gen1 gets its power from the ignition switch, goes thru the Gen1 lamp and then to the #1 terminal on the driver side alternator.

Gen2 is simular but ithe ignition switch energizes the Gen2 relay and the relay supplies 24v thru the Gen2 light, Gen2 relay and then to the #1 terminal on the passenger side alternator

Right click on the picture and choose "Open Link in New Window"

Can you tell us what symptoms you are having with your ongoing issues?

 

[ratstalker]

Thanks for the diagrams. I had EVERYTHING working 9 months or so ago, then my voltmeter failed about 2 months ago, then the gen 1 light, along with a lack of charging. I replaced the components in alternator one, and still have the same problem, so get to dig deeper this weekend...

 

[Crash_AF]

Check to make sure that the Gen 1 bulb is not burned out. It is essential to make the charging circuit work.

The relays are standard Bosch relays commonly used for fog light relays or other automotive applications. Ask for an AC relay for a 1989 Jeep Cherokee at the parts store.

The starter relay is a common GM relay used for the HVAC controls. I believe that it is the same as the Heater Relay in a 1978 Chevy truck with AC.

There is no relay for the GEN 1 side. The three relays under the dash are for the 24V equipment to isolate the 24V from the 12V systems. 24V Voltmeter, GEN 2 and Starter Solenoid.

Pull the voltmeter out and check for voltage between the orange and black wires. Should be 24V there. If there isn't, check the relay under the dash (one of the two black relays). To test, you can swap the two and see if the voltmeter works and the Gen 2 light doesn't.

Gen 1 could be a bad ground or power connection on the alternator itself. But the first and easiest thing to check, especially since the lights in the instrument panel are troublesome sometimes, is the Gen 1 light in the cluster. A failed bulb WILL prevent the alternator from charging and an LED (probably not your problem, but I'll include for future searchers) will not work because it doesn't provide enough resistance.

Later,
Joe